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Space Adventures, Ltd. | Zero Gravity Flight

Aboard a specially modified Boeing 727-200, G-FORCE ONE, weightlessness is achieved by doing aerobatic maneuvers known as parabolas. Specially trained pilots perform these aerobatic maneuvers which are not simulated in any way. ZERO-G passengers experience true weightlessness.

Before starting a parabola, G-FORCE ONEflies level to the horizon at an altitude of 24,000 feet. The pilots then begins to pull up, gradually increasing the angle of the aircraft to about 45 to the horizon reaching an altitude of 34,000 feet. During this pull-up, passengers will feel the pull of 1.8 Gs. Next the plane is pushed over to create the zero gravity segment of the parabola. For the next 20-30 seconds everything in the plane is weightless. Next a gentle pull-out is started which allows the flyers to stabilize on the aircraft floor. This maneuver is repeated 12-15 times, each taking about ten miles of airspace to perform.

In addition to achieving zero gravity, G-FORCE ONEalso flies a parabola designed to offer Lunar gravity (one sixth your weight)and Martian gravity (one third your weight). This is created by flying a larger arc over the top of the parabola.

G-FORCE ONEflies in a FAA designated airspace that is approximately 100 miles long and ten miles wide. Usually three to five parabolas are flown consecutively with short periods of level flight between each set.

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Space Adventures, Ltd. | Zero Gravity Flight

Space Flight | Evergreen Aviation & Space Museum | Wings …

Mercury Space Capsule Designed to put Americas 1st astronauts in space, Project Mercury began in October, 1958 as one of the 1st programs of National Aeronautics and Space Administration (NASA). The one man capsule was created by NASA, and built by McDonnell Aircraft. A total of 20 capsules were built, but only nine would fly in space; six with humans aboard, two with chimpanzees and one unmanned. Modified Redstone and Atlas missile were used to boost the capsules into space, and they helped America get a foothold on the space frontier. This particular Mercury Capsule, serial number 10, was not flown. It is on loan from the National Air & Space Museum.

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Space Flight | Evergreen Aviation & Space Museum | Wings …

Spaceflight Now The leading source for online space news

The White Houses $19.9 billion NASA budget outline released Monday would continue development of NASAs heavy-lift Space Launch System rocket and Orion crew capsule and begin the deployment of a mini-space station around the moon as soon as 2022, but the proposal would cancel WFIRST, a flagship-class astronomy mission planned for launch in the mid-2020s.

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Spaceflight Now The leading source for online space news

Space Shuttle – Wikipedia

Space ShuttleFunctionCrewed orbital launch and reentryManufacturerUnited Space AllianceThiokol/Alliant Techsystems (SRBs)Lockheed Martin/Martin Marietta (ET)Boeing/Rockwell (orbiter)Country of originUnited StatesProject costUS$ 210 billion (2010)[1][2][3]Cost per launchUS$ 450 million (2011)[4] to 1.5 billion (2011)[2][3][5][6]SizeHeight56.1 m (184.2 ft)Diameter8.7 m (28.5 ft)Mass2,030 t (4,470,000 lb)Stages2CapacityPayload to LEO27,500kg (60,600lb)Payload to ISS16,050kg (35,380lb)Payload to GTO3,810kg (8,400lb)Payload to Polar orbit12,700kg (28,000lb)Payload to Earth return14,400kg (31,700lb)[7]Launch historyStatusRetiredLaunch sitesLC-39, Kennedy Space CenterSLC-6, Vandenberg AFB (unused)Total launches135Successes134 launches and 133 landingsFailures2Challenger (launch failure, 7 fatalities),Columbia (re-entry failure, 7 fatalities)First flightApril 12, 1981Last flightJuly 21, 2011Notable payloadsTracking and Data Relay SatellitesSpacelabHubble Space TelescopeGalileo, Magellan, UlyssesCompton Gamma Ray ObservatoryMir Docking ModuleChandra X-ray ObservatoryISS componentsBoosters – Solid Rocket BoostersNo. boosters2[8]Engines2 solidThrust12,500kN (2,800,000lbf) each, sea level liftoffSpecific impulse269 seconds (2.64km/s)Burn time124 sFuelSolid (Ammonium perchlorate composite propellant)First stage – Orbiter plus External TankEngines3 SSMEs located on OrbiterThrust5,250kN (1,180,000lbf) total, sea level liftoff [9]Specific impulse455 seconds (4.46km/s)Burn time480 sFuelLOX/LH2

The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U.S. National Aeronautics and Space Administration (NASA), as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development.[10] The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. In addition to the prototype whose completion was cancelled, five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST); conducted science experiments in orbit; and participated in construction and servicing of the International Space Station. The Shuttle fleet’s total mission time was 1322 days, 19 hours, 21 minutes and 23 seconds.[11]

Shuttle components included the Orbiter Vehicle (OV) with three clustered Rocketdyne RS-25 main engines, a pair of recoverable solid rocket boosters (SRBs), and the expendable external tank (ET) containing liquid hydrogen and liquid oxygen. The Space Shuttle was launched vertically, like a conventional rocket, with the two SRBs operating in parallel with the OV’s three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, which used the orbiter’s two Orbital Maneuvering System (OMS) engines. At the conclusion of the mission, the orbiter fired its OMS to de-orbit and re-enter the atmosphere. The orbiter then glided as a spaceplane to a runway landing, usually to the Shuttle Landing Facility at Kennedy Space Center, Florida or Rogers Dry Lake in Edwards Air Force Base, California. After landing at Edwards, the orbiter was flown back to the KSC on the Shuttle Carrier Aircraft, a specially modified version of the Boeing 747.

The first orbiter, Enterprise, was built in 1976, used in Approach and Landing Tests and had no orbital capability. Four fully operational orbiters were initially built: Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in mission accidents: Challenger in 1986 and Columbia in 2003, with a total of fourteen astronauts killed. A fifth operational (and sixth in total) orbiter, Endeavour, was built in 1991 to replace Challenger. The Space Shuttle was retired from service upon the conclusion of Atlantis’s final flight on July 21, 2011. The U.S. has since relied on the Russian Soyuz spacecraft to transport supplies and astronauts to the International Space Station.

The Space Shuttle was a partially reusable[12] human spaceflight vehicle capable of reaching low Earth orbit, commissioned and operated by the US National Aeronautics and Space Administration (NASA) from 1981 to 2011. It resulted from shuttle design studies conducted by NASA and the US Air Force in the 1960s and was first proposed for development as part of an ambitious second-generation Space Transportation System (STS) of space vehicles to follow the Apollo program in a September 1969 report of a Space Task Group headed by Vice President Spiro Agnew to President Richard Nixon. Nixon’s post-Apollo NASA budgeting withdrew support of all system components except the Shuttle, to which NASA applied the STS name.[10]

The vehicle consisted of a spaceplane for orbit and re-entry, fueled from expendable liquid hydrogen and liquid oxygen tanks, with reusable strap-on solid booster rockets. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982, all launched from the Kennedy Space Center, Florida. The system was retired from service in 2011 after 135 missions,[13] with Atlantis making the final launch of the three-decade Shuttle program on July 8, 2011.[14] The program ended after Atlantis landed at the Kennedy Space Center on July 21, 2011. Major missions included launching numerous satellites and interplanetary probes,[15] conducting space science experiments, and servicing and construction of space stations. The first orbiter vehicle, named Enterprise, was used in the initial Approach and Landing Tests phase but installation of engines, heat shielding, and other equipment necessary for orbital flight was cancelled.[16] A total of five operational orbiters were built, and of these, two were destroyed in accidents.

It was used for orbital space missions by NASA, the US Department of Defense, the European Space Agency, Japan, and Germany.[17][18] The United States funded Shuttle development and operations except for the Spacelab modules used on D1 and D2sponsored by Germany.[17][19][20][21][22] SL-J was partially funded by Japan.[18]

At launch, it consisted of the “stack”, including the dark orange external tank (ET) (for the first two launches the tank was painted white);[23][24] two white, slender solid rocket boosters (SRBs); and the Orbiter Vehicle, which contained the crew and payload. Some payloads were launched into higher orbits with either of two different upper stages developed for the STS (single-stage Payload Assist Module or two-stage Inertial Upper Stage). The Space Shuttle was stacked in the Vehicle Assembly Building, and the stack mounted on a mobile launch platform held down by four frangible nuts[25] on each SRB, which were detonated at launch.[26]

The Shuttle stack launched vertically like a conventional rocket. It lifted off under the power of its two SRBs and three main engines, which were fueled by liquid hydrogen and liquid oxygen from the ET. The Space Shuttle had a two-stage ascent. The SRBs provided additional thrust during liftoff and first-stage flight. About two minutes after liftoff, frangible nuts were fired, releasing the SRBs, which then parachuted into the ocean, to be retrieved by NASA recovery ships for refurbishment and reuse. The orbiter and ET continued to ascend on an increasingly horizontal flight path under power from its main engines. Upon reaching 17,500mph (7.8km/s), necessary for low Earth orbit, the main engines were shut down. The ET, attached by two frangible nuts[27] was then jettisoned to burn up in the atmosphere.[28] After jettisoning the external tank, the orbital maneuvering system (OMS) engines were used to adjust the orbit. The orbiter carried astronauts and payloads such as satellites or space station parts into low Earth orbit, the Earth’s upper atmosphere or thermosphere.[29] Usually, five to seven crew members rode in the orbiter. Two crew members, the commander and pilot, were sufficient for a minimal flight, as in the first four “test” flights, STS-1 through STS-4. The typical payload capacity was about 50,045 pounds (22,700kg) but could be increased depending on the choice of launch configuration. The orbiter carried its payload in a large cargo bay with doors that opened along the length of its top, a feature which made the Space Shuttle unique among spacecraft. This feature made possible the deployment of large satellites such as the Hubble Space Telescope and also the capture and return of large payloads back to Earth.

When the orbiter’s space mission was complete, it fired its OMS thrusters to drop out of orbit and re-enter the lower atmosphere.[29] During descent, the orbiter passed through different layers of the atmosphere and decelerated from hypersonic speed primarily by aerobraking. In the lower atmosphere and landing phase, it was more like a glider but with reaction control system (RCS) thrusters and fly-by-wire-controlled hydraulically actuated flight surfaces controlling its descent. It landed on a long runway as a conventional aircraft. The aerodynamic shape was a compromise between the demands of radically different speeds and air pressures during re-entry, hypersonic flight, and subsonic atmospheric flight. As a result, the orbiter had a relatively high sink rate at low altitudes, and it transitioned during re-entry from using RCS thrusters at very high altitudes to flight surfaces in the lower atmosphere.

The formal design of what became the Space Shuttle began with the “Phase A” contract design studies issued in the late 1960s. Conceptualization had begun two decades earlier, before the Apollo program of the 1960s. One of the places the concept of a spacecraft returning from space to a horizontal landing originated was within NACA, in 1954, in the form of an aeronautics research experiment later named the X-15. The NACA proposal was submitted by Walter Dornberger.

In 1958, the X-15 concept further developed into a proposal to launch an X-15 into space, and another X-series spaceplane proposal, named X-20 Dyna-Soar, as well as variety of aerospace plane concepts and studies. Neil Armstrong was selected to pilot both the X-15 and the X-20. Though the X-20 was not built, another spaceplane similar to the X-20 was built several years later and delivered to NASA in January 1966 called the HL-10 (“HL” indicated “horizontal landing”).

In the mid-1960s, the US Air Force conducted classified studies on next-generation space transportation systems and concluded that semi-reusable designs were the cheapest choice. It proposed a development program with an immediate start on a “ClassI” vehicle with expendable boosters, followed by slower development of a “ClassII” semi-reusable design and possible “ClassIII” fully reusable design later. In 1967, George Mueller held a one-day symposium at NASA headquarters to study the options. Eighty people attended and presented a wide variety of designs, including earlier US Air Force designs such as the X-20 Dyna-Soar.

In 1968, NASA officially began work on what was then known as the Integrated Launch and Re-entry Vehicle (ILRV). At the same time, NASA held a separate Space Shuttle Main Engine (SSME) competition. NASA offices in Houston and Huntsville jointly issued a Request for Proposal (RFP) for ILRV studies to design a spacecraft that could deliver a payload to orbit but also re-enter the atmosphere and fly back to Earth. For example, one of the responses was for a two-stage design, featuring a large booster and a small orbiter, called the DC-3, one of several Phase A Shuttle designs. After the aforementioned “Phase A” studies, B, C, and D phases progressively evaluated in-depth designs up to 1972. In the final design, the bottom stage consisted of recoverable solid rocket boosters, and the top stage used an expendable external tank.[30]

In 1969, President Richard Nixon decided to support proceeding with Space Shuttle development. A series of development programs and analysis refined the basic design, prior to full development and testing. In August 1973, the X-24B proved that an unpowered spaceplane could re-enter Earth’s atmosphere for a horizontal landing.

Across the Atlantic, European ministers met in Belgium in 1973 to authorize Western Europe’s manned orbital project and its main contribution to Space Shuttlethe Spacelab program.[31] Spacelab would provide a multidisciplinary orbital space laboratory and additional space equipment for the Shuttle.[31]

The Space Shuttle was the first operational orbital spacecraft designed for reuse. It carried different payloads to low Earth orbit, provided crew rotation and supplies for the International Space Station (ISS), and performed satellite servicing and repair. The orbiter could also recover satellites and other payloads from orbit and return them to Earth. Each Shuttle was designed for a projected lifespan of 100 launches or ten years of operational life, although this was later extended. The person in charge of designing the STS was Maxime Faget, who had also overseen the Mercury, Gemini, and Apollo spacecraft designs. The crucial factor in the size and shape of the Shuttle orbiter was the requirement that it be able to accommodate the largest planned commercial and military satellites, and have over 1,000 mile cross-range recovery range to meet the requirement for classified USAF missions for a once-around abort from a launch to a polar orbit. The militarily specified 1,085nmi (2,009km; 1,249mi) cross range requirement was one of the primary reasons for the Shuttle’s large wings, compared to modern commercial designs with very minimal control surfaces and glide capability. Factors involved in opting for solid rockets and an expendable fuel tank included the desire of the Pentagon to obtain a high-capacity payload vehicle for satellite deployment, and the desire of the Nixon administration to reduce the costs of space exploration by developing a spacecraft with reusable components.

Each Space Shuttle was a reusable launch system composed of three main assemblies: the reusable OV, the expendable ET, and the two reusable SRBs.[32] Only the OV entered orbit shortly after the tank and boosters are jettisoned. The vehicle was launched vertically like a conventional rocket, and the orbiter glided to a horizontal landing like an airplane, after which it was refurbished for reuse. The SRBs parachuted to splashdown in the ocean where they were towed back to shore and refurbished for later Shuttle missions.

Five operational OVs were built: Columbia (OV-102), Challenger (OV-099), Discovery (OV-103), Atlantis (OV-104), and Endeavour (OV-105). A mock-up, Inspiration, currently stands at the entrance to the Astronaut Hall of Fame. An additional craft, Enterprise (OV-101), was built for atmospheric testing gliding and landing; it was originally intended to be outfitted for orbital operations after the test program, but it was found more economical to upgrade the structural test article STA-099 into orbiter Challenger (OV-099). Challenger disintegrated 73 seconds after launch in 1986, and Endeavour was built as a replacement from structural spare components. Building Endeavour cost about US$1.7billion. Columbia broke apart over Texas during re-entry in 2003. A Space Shuttle launch cost around $450million.[33]

Roger A. Pielke, Jr. has estimated that the Space Shuttle program cost about US$170billion (2008 dollars) through early 2008; the average cost per flight was about US$1.5billion.[34] Two missions were paid for by Germany, Spacelab D1 and D2 (D for Deutschland) with a payload control center in Oberpfaffenhofen.[35][36] D1 was the first time that control of a manned STS mission payload was not in U.S. hands.[17]

At times, the orbiter itself was referred to as the Space Shuttle. This was not technically correct as the Space Shuttle was the combination of the orbiter, the external tank, and the two solid rocket boosters. These components, once assembled in the Vehicle Assembly Building originally built to assemble the Apollo Saturn V rocket, were commonly referred to as the “stack”.[37]

Responsibility for the Shuttle components was spread among multiple NASA field centers. The Kennedy Space Center was responsible for launch, landing and turnaround operations for equatorial orbits (the only orbit profile actually used in the program), the US Air Force at the Vandenberg Air Force Base was responsible for launch, landing and turnaround operations for polar orbits (though this was never used), the Johnson Space Center served as the central point for all Shuttle operations, the Marshall Space Flight Center was responsible for the main engines, external tank, and solid rocket boosters, the John C. Stennis Space Center handled main engine testing, and the Goddard Space Flight Center managed the global tracking network.[38]

The orbiter resembled a conventional aircraft, with double-delta wings swept 81 at the inner leading edge and 45 at the outer leading edge. Its vertical stabilizer’s leading edge was swept back at a 50 angle. The four elevons, mounted at the trailing edge of the wings, and the rudder/speed brake, attached at the trailing edge of the stabilizer, with the body flap, controlled the orbiter during descent and landing.

The orbiter’s 60-foot (18m)-long payload bay, comprising most of the fuselage, could accommodate cylindrical payloads up to 15 feet (4.6m) in diameter. Information declassified in 2011 showed that these measurements were chosen specifically to accommodate the KH-9 HEXAGON spy satellite operated by the National Reconnaissance Office.[39] Two mostly-symmetrical lengthwise payload bay doors hinged on either side of the bay comprised its entire top. Payloads were generally loaded horizontally into the bay while the orbiter was standing upright on the launch pad and unloaded vertically in the near-weightless orbital environment by the orbiter’s robotic remote manipulator arm (under astronaut control), EVA astronauts, or under the payloads’ own power (as for satellites attached to a rocket “upper stage” for deployment.)

Three Space Shuttle Main Engines (SSMEs) were mounted on the orbiter’s aft fuselage in a triangular pattern. The engine nozzles could gimbal 10.5 degrees up and down, and 8.5 degrees from side to side during ascent to change the direction of their thrust to steer the Shuttle. The orbiter structure was made primarily from aluminum alloy, although the engine structure was made primarily from titanium alloy.

The operational orbiters built were OV-102 Columbia, OV-099 Challenger, OV-103 Discovery, OV-104 Atlantis, and OV-105 Endeavour.[40]

Space Shuttle Endeavour being transported by a Shuttle Carrier Aircraft

An overhead view of Atlantis as it sits atop the Mobile Launcher Platform (MLP) before STS-79. Two Tail Service Masts (TSMs) to either side of the orbiter’s tail provide umbilical connections for propellant loading and electrical power.

Water is released onto the mobile launcher platform on Launch Pad 39A at the start of a sound suppression system test in 2004. During launch, 350,000 US gallons (1,300,000L) of water are poured onto the pad in 41 seconds.[41]

The main function of the Space Shuttle external tank was to supply the liquid oxygen and hydrogen fuel to the main engines. It was also the backbone of the launch vehicle, providing attachment points for the two solid rocket boosters and the orbiter. The external tank was the only part of the Shuttle system that was not reused. Although the external tanks were always discarded, it would have been possible to take them into orbit and re-use them (such as a wet workshop for incorporation into a space station).[28][42]

Two solid rocket boosters (SRBs) each provided 12,500kN (2,800,000lbf) of thrust at liftoff,[43] which was 83% of the total thrust at liftoff. The SRBs were jettisoned two minutes after launch at a height of about 46km (150,000ft), and then deployed parachutes and landed in the ocean to be recovered.[44] The SRB cases were made of steel about inch (13mm) thick.[45] The solid rocket boosters were re-used many times; the casing used in Ares I engine testing in 2009 consisted of motor cases that had been flown, collectively, on 48 Shuttle missions, including STS-1.[46]

Astronauts who have flown on multiple spacecraft report that Shuttle delivers a rougher ride than Apollo or Soyuz.[47][48] The additional vibration is caused by the solid rocket boosters, as solid fuel does not burn as evenly as liquid fuel. The vibration dampens down after the solid rocket boosters have been jettisoned.[49][50]

Two SRB on the crawler prior to mating with the Shuttle

SRB sections filled with solid propellant being assembled

Orbiter and the external tank, flanked by the two solid rocket boosters

The orbiter could be used in conjunction with a variety of add-ons depending on the mission. This included orbital laboratories (Spacelab, Spacehab), boosters for launching payloads farther into space (Inertial Upper Stage, Payload Assist Module), and other functions, such as provided by Extended Duration Orbiter, Multi-Purpose Logistics Modules, or Canadarm (RMS). An upper stage called Transfer Orbit Stage (Orbital Science Corp. TOS-21) was also used once with the orbiter.[51] Other types of systems and racks were part of the modular Spacelab system pallets, igloo, IPS, etc., which also supported special missions such as SRTM.[52]

A major component of the Space Shuttle Program was Spacelab, primarily contributed by a consortium of European countries, and operated in conjunction with the United States and international partners.[52] Supported by a modular system of pressurized modules, pallets, and systems, Spacelab missions executed on multidisciplinary science, orbital logistics, and international cooperation.[52] Over 29 missions flew on subjects ranging from astronomy, microgravity, radar, and life sciences, to name a few.[52] Spacelab hardware also supported missions such as Hubble (HST) servicing and space station resupply.[52] STS-2 and STS-3 provided testing, and the first full mission was Spacelab-1 (STS-9) launched on November 28, 1983.[52]

Spacelab formally began in 1973, after a meeting in Brussels, Belgium, by European heads of state.[31] Within the decade, Spacelab went into orbit and provided Europe and the United States with an orbital workshop and hardware system.[31] International cooperation, science, and exploration were realized on Spacelab.[52]

The Shuttle was one of the earliest craft to use a computerized fly-by-wire digital flight control system. This means no mechanical or hydraulic linkages connected the pilot’s control stick to the control surfaces or reaction control system thrusters. The control algorithm, which used a classical Proportional Integral Derivative (PID) approach, was developed and maintained by Honeywell.[citation needed] The Shuttle’s fly-by-wire digital flight control system was composed of 4 control systems each addressing a different mission phase: Ascent, Descent, On-Orbit and Aborts.[citation needed] Honeywell is also credited with the design and implementation of the Shuttle’s Nose Wheel Steering Control Algorithm that allowed the Orbiter to safely land at Kennedy Space Center’s Shuttle Runway.[citation needed]

A concern with using digital fly-by-wire systems on the Shuttle was reliability. Considerable research went into the Shuttle computer system. The Shuttle used five identical redundant IBM 32-bit general purpose computers (GPCs), model AP-101, constituting a type of embedded system. Four computers ran specialized software called the Primary Avionics Software System (PASS). A fifth backup computer ran separate software called the Backup Flight System (BFS). Collectively they were called the Data Processing System (DPS).[53][54]

The design goal of the Shuttle’s DPS was fail-operational/fail-safe reliability. After a single failure, the Shuttle could still continue the mission. After two failures, it could still land safely.

The four general-purpose computers operated essentially in lockstep, checking each other. If one computer provided a different result than the other three (i.e. the one computer failed), the three functioning computers “voted” it out of the system. This isolated it from vehicle control. If a second computer of the three remaining failed, the two functioning computers voted it out. A very unlikely failure mode would have been where two of the computers produced result A, and two produced result B (a two-two split). In this unlikely case, one group of two was to be picked at random.

The Backup Flight System (BFS) was separately developed software running on the fifth computer, used only if the entire four-computer primary system failed. The BFS was created because although the four primary computers were hardware redundant, they all ran the same software, so a generic software problem could crash all of them. Embedded system avionic software was developed under totally different conditions from public commercial software: the number of code lines was tiny compared to a public commercial software product, changes were only made infrequently and with extensive testing, and many programming and test personnel worked on the small amount of computer code. However, in theory it could have still failed, and the BFS existed for that contingency. While the BFS could run in parallel with PASS, the BFS never engaged to take over control from PASS during any Shuttle mission.

The software for the Shuttle computers was written in a high-level language called HAL/S, somewhat similar to PL/I. It is specifically designed for a real time embedded system environment.

The IBM AP-101 computers originally had about 424 kilobytes of magnetic core memory each. The CPU could process about 400,000 instructions per second. They had no hard disk drive, and loaded software from magnetic tape cartridges.

In 1990, the original computers were replaced with an upgraded model AP-101S, which had about 2.5 times the memory capacity (about 1 megabyte) and three times the processor speed (about 1.2million instructions per second). The memory was changed from magnetic core to semiconductor with battery backup.

Early Shuttle missions, starting in November 1983, took along the Grid Compass, arguably one of the first laptop computers. The GRiD was given the name SPOC, for Shuttle Portable Onboard Computer. Use on the Shuttle required both hardware and software modifications which were incorporated into later versions of the commercial product. It was used to monitor and display the Shuttle’s ground position, path of the next two orbits, show where the Shuttle had line of sight communications with ground stations, and determine points for location-specific observations of the Earth. The Compass sold poorly, as it cost at least US$8000, but it offered unmatched performance for its weight and size.[55] NASA was one of its main customers.[56]

During its service life, the Shuttle’s Control System never experienced a failure. Many of the lessons learned have been used to design today’s high speed control algorithms.[57]

The prototype orbiter Enterprise originally had a flag of the United States on the upper surface of the left wing and the letters “USA” in black on the right wing. The name “Enterprise” was painted in black on the payload bay doors just above the hinge and behind the crew module; on the aft end of the payload bay doors was the NASA “worm” logotype in gray. Underneath the rear of the payload bay doors on the side of the fuselage just above the wing is the text “United States” in black with a flag of the United States ahead of it.

The first operational orbiter, Columbia, originally had the same markings as Enterprise, although the letters “USA” on the right wing were slightly larger and spaced farther apart. Columbia also had black markings which Enterprise lacked on its forward RCS module, around the cockpit windows, and on its vertical stabilizer, and had distinctive black “chines” on the forward part of its upper wing surfaces, which none of the other orbiters had.

Challenger established a modified marking scheme for the shuttle fleet that was matched by Discovery, Atlantis and Endeavour. The letters “USA” in black above an American flag were displayed on the left wing, with the NASA “worm” logotype in gray centered above the name of the orbiter in black on the right wing. The name of the orbiter was inscribed not on the payload bay doors, but on the forward fuselage just below and behind the cockpit windows. This would make the name visible when the shuttle was photographed in orbit with the doors open.

In 1983, Enterprise had its wing markings changed to match Challenger, and the NASA “worm” logotype on the aft end of the payload bay doors was changed from gray to black. Some black markings were added to the nose, cockpit windows and vertical tail to more closely resemble the flight vehicles, but the name “Enterprise” remained on the payload bay doors as there was never any need to open them. Columbia had its name moved to the forward fuselage to match the other flight vehicles after STS-61-C, during the 198688 hiatus when the shuttle fleet was grounded following the loss of Challenger, but retained its original wing markings until its last overhaul (after STS-93), and its unique black wing “chines” for the remainder of its operational life.

Beginning in 1998, the flight vehicles’ markings were modified to incorporate the NASA “meatball” insignia. The “worm” logotype, which the agency had phased out, was removed from the payload bay doors and the “meatball” insignia was added aft of the “United States” text on the lower aft fuselage. The “meatball” insignia was also displayed on the left wing, with the American flag above the orbiter’s name, left-justified rather than centered, on the right wing. The three surviving flight vehicles, Discovery, Atlantis and Endeavour, still bear these markings as museum displays. Enterprise became the property of the Smithsonian Institution in 1985 and was no longer under NASA’s control when these changes were made, hence the prototype orbiter still has its 1983 markings and still has its name on the payload bay doors.

The Space Shuttle was initially developed in the 1970s,[58] but received many upgrades and modifications afterward to improve performance, reliability and safety. Internally, the Shuttle remained largely similar to the original design, with the exception of the improved avionics computers. In addition to the computer upgrades, the original analog primary flight instruments were replaced with modern full-color, flat-panel display screens, called a glass cockpit, which is similar to those of contemporary airliners. To facilitate construction of ISS, the internal airlocks of each orbiter except Columbia[59] were replaced with external docking systems to allow for a greater amount of cargo to be stored on the Shuttle’s mid-deck during station resupply missions.

The Space Shuttle Main Engines (SSMEs) had several improvements to enhance reliability and power. This explains phrases such as “Main engines throttling up to 104 percent.” This did not mean the engines were being run over a safe limit. The 100 percent figure was the original specified power level. During the lengthy development program, Rocketdyne determined the engine was capable of safe reliable operation at 104 percent of the originally specified thrust. NASA could have rescaled the output number, saying in essence 104 percent is now 100 percent. To clarify this would have required revising much previous documentation and software, so the 104 percent number was retained. SSME upgrades were denoted as “block numbers”, such as block I, block II, and block IIA. The upgrades improved engine reliability, maintainability and performance. The 109% thrust level was finally reached in flight hardware with the Block II engines in 2001. The normal maximum throttle was 104 percent, with 106 percent or 109 percent used for mission aborts.

For the first two missions, STS-1 and STS-2, the external tank was painted white to protect the insulation that covers much of the tank, but improvements and testing showed that it was not required. The weight saved by not painting the tank resulted in an increase in payload capability to orbit.[60] Additional weight was saved by removing some of the internal “stringers” in the hydrogen tank that proved unnecessary. The resulting “light-weight external tank” was first flown on STS-6 [61] and used on the majority of Shuttle missions. STS-91 saw the first flight of the “super light-weight external tank”. This version of the tank was made of the 2195 aluminum-lithium alloy. It weighed 3.4 metric tons (7,500lb) less than the last run of lightweight tanks, allowing the Shuttle to deliver heavy elements to ISS’s high inclination orbit.[61] As the Shuttle was always operated with a crew, each of these improvements was first flown on operational mission flights.

The solid rocket boosters underwent improvements as well. Design engineers added a third O-ring seal to the joints between the segments after the 1986 Space Shuttle Challenger disaster.

Several other SRB improvements were planned to improve performance and safety, but never came to be. These culminated in the considerably simpler, lower cost, probably safer and better-performing Advanced Solid Rocket Booster. These rockets entered production in the early to mid-1990s to support the Space Station, but were later canceled to save money after the expenditure of $2.2billion.[62] The loss of the ASRB program resulted in the development of the Super LightWeight external Tank (SLWT), which provided some of the increased payload capability, while not providing any of the safety improvements. In addition, the US Air Force developed their own much lighter single-piece SRB design using a filament-wound system, but this too was canceled.

STS-70 was delayed in 1995, when woodpeckers bored holes in the foam insulation of Discovery’s external tank. Since then, NASA has installed commercial plastic owl decoys and inflatable owl balloons which had to be removed prior to launch.[63] The delicate nature of the foam insulation had been the cause of damage to the Thermal Protection System, the tile heat shield and heat wrap of the orbiter. NASA remained confident that this damage, while it was the primary cause of the Space Shuttle Columbia disaster on February 1, 2003, would not jeopardize the completion of the International Space Station (ISS) in the projected time allotted.

A cargo-only, unmanned variant of the Shuttle was variously proposed and rejected since the 1980s. It was called the Shuttle-C, and would have traded re-usability for cargo capability, with large potential savings from reusing technology developed for the Space Shuttle. Another proposal was to convert the payload bay into a passenger area, with versions ranging from 30 to 74 seats, three days in orbit, and cost US$1.5million per seat.[64]

On the first four Shuttle missions, astronauts wore modified US Air Force high-altitude full-pressure suits, which included a full-pressure helmet during ascent and descent. From the fifth flight, STS-5, until the loss of Challenger, one-piece light blue nomex flight suits and partial-pressure helmets were worn. A less-bulky, partial-pressure version of the high-altitude pressure suits with a helmet was reinstated when Shuttle flights resumed in 1988. The Launch-Entry Suit ended its service life in late 1995, and was replaced by the full-pressure Advanced Crew Escape Suit (ACES), which resembled the Gemini space suit in design, but retained the orange color of the Launch-Entry Suit.

To extend the duration that orbiters could stay docked at the ISS, the Station-to-Shuttle Power Transfer System (SSPTS) was installed. The SSPTS allowed these orbiters to use power provided by the ISS to preserve their consumables. The SSPTS was first used successfully on STS-118.

Orbiter[65] (for Endeavour, OV-105)

External tank (for SLWT)

Solid Rocket Boosters

System Stack

All Space Shuttle missions were launched from Kennedy Space Center (KSC). The weather criteria used for launch included, but were not limited to: precipitation, temperatures, cloud cover, lightning forecast, wind, and humidity.[70] The Shuttle was not launched under conditions where it could have been struck by lightning. Aircraft are often struck by lightning with no adverse effects because the electricity of the strike is dissipated through its conductive structure and the aircraft is not electrically grounded. Like most jet airliners, the Shuttle was mainly constructed of conductive aluminum, which would normally shield and protect the internal systems. However, upon liftoff the Shuttle sent out a long exhaust plume as it ascended, and this plume could have triggered lightning by providing a current path to ground. The NASA Anvil Rule for a Shuttle launch stated that an anvil cloud could not appear within a distance of 10 nautical miles.[71] The Shuttle Launch Weather Officer monitored conditions until the final decision to scrub a launch was announced. In addition, the weather conditions had to be acceptable at one of the Transatlantic Abort Landing sites (one of several Space Shuttle abort modes) to launch as well as the solid rocket booster recovery area.[70][72] While the Shuttle might have safely endured a lightning strike, a similar strike caused problems on Apollo 12, so for safety NASA chose not to launch the Shuttle if lightning was possible (NPR8715.5).

Historically, the Shuttle was not launched if its flight would run from December to January (a year-end rollover or YERO). Its flight software, designed in the 1970s, was not designed for this, and would require the orbiter’s computers be reset through a change of year, which could cause a glitch while in orbit. In 2007, NASA engineers devised a solution so Shuttle flights could cross the year-end boundary.[73]

After the final hold in the countdown at T-minus 9 minutes, the Shuttle went through its final preparations for launch, and the countdown was automatically controlled by the Ground Launch Sequencer (GLS), software at the Launch Control Center, which stopped the count if it sensed a critical problem with any of the Shuttle’s onboard systems. The GLS handed off the count to the Shuttle’s on-board computers at T minus 31 seconds, in a process called auto sequence start.

At T-minus 16 seconds, the massive sound suppression system (SPS) began to drench the Mobile Launcher Platform (MLP) and SRB trenches with 300,000 US gallons (1,100m3) of water to protect the Orbiter from damage by acoustical energy and rocket exhaust reflected from the flame trench and MLP during lift off.[74][75]

At T-minus 10 seconds, hydrogen igniters were activated under each engine bell to quell the stagnant gas inside the cones before ignition. Failure to burn these gases could trip the onboard sensors and create the possibility of an overpressure and explosion of the vehicle during the firing phase. The main engine turbopumps also began charging the combustion chambers with liquid hydrogen and liquid oxygen at this time. The computers reciprocated this action by allowing the redundant computer systems to begin the firing phase.

The three main engines (SSMEs) started at T-6.6 seconds. The main engines ignited sequentially via the Shuttle’s general purpose computers (GPCs) at 120 millisecond intervals. All three SSMEs were required to reach 90% rated thrust within three seconds, otherwise the onboard computers would initiate an RSLS abort. If all three engines indicated nominal performance by T-3 seconds, they were commanded to gimbal to liftoff configuration and the command would be issued to arm the SRBs for ignition at T-0.[76] Between T-6.6 seconds and T-3 seconds, while the SSMEs were firing but the SRBs were still bolted to the pad, the offset thrust caused the entire launch stack (boosters, tank and orbiter) to pitch down 650mm (25.5in) measured at the tip of the external tank. The three second delay after confirmation of SSME operation was to allow the stack to return to nearly vertical. At T-0 seconds, the 8 frangible nuts holding the SRBs to the pad were detonated, the SSMEs were commanded to 100% throttle, and the SRBs were ignited. By T+0.23 seconds, the SRBs built up enough thrust for liftoff to commence, and reached maximum chamber pressure by T+0.6 seconds.[77] The Johnson Space Center’s Mission Control Center assumed control of the flight once the SRBs had cleared the launch tower.

Shortly after liftoff, the Shuttle’s main engines were throttled up to 104.5% and the vehicle began a combined roll, pitch and yaw maneuver that placed it onto the correct heading (azimuth) for the planned orbital inclination and in a heads down attitude with wings level. The Shuttle flew upside down during the ascent phase. This orientation allowed a trim angle of attack that was favorable for aerodynamic loads during the region of high dynamic pressure, resulting in a net positive load factor, as well as providing the flight crew with a view of the horizon as a visual reference. The vehicle climbed in a progressively flattening arc, accelerating as the mass of the SRBs and main tank decreased. To achieve low orbit requires much more horizontal than vertical acceleration. This was not visually obvious, since the vehicle rose vertically and was out of sight for most of the horizontal acceleration. The near circular orbital velocity at the 380 kilometers (236mi) altitude of the International Space Station is 27,650km/h (17,180mph), roughly equivalent to Mach 23 at sea level. As the International Space Station orbits at an inclination of 51.6 degrees, missions going there must set orbital inclination to the same value in order to rendezvous with the station.

Around 30 seconds into ascent, the SSMEs were throttled downusually to 72%, though this variedto reduce the maximum aerodynamic forces acting on the Shuttle at a point called Max Q. Additionally, the propellant grain design of the SRBs caused their thrust to drop by about 30% by 50 seconds into ascent. Once the Orbiter’s guidance verified that Max Q would be within Shuttle structural limits, the main engines were throttled back up to 104.5%; this throttling down and back up was called the “thrust bucket”. To maximize performance, the throttle level and timing of the thrust bucket was shaped to bring the Shuttle as close to aerodynamic limits as possible.[78]

At around T+126 seconds, pyrotechnic fasteners released the SRBs and small separation rockets pushed them laterally away from the vehicle. The SRBs parachuted back to the ocean to be reused. The Shuttle then began accelerating to orbit on the main engines. Acceleration at this point would typically fall to .9 g, and the vehicle would take on a somewhat nose-up angle to the horizon it used the main engines to gain and then maintain altitude while it accelerated horizontally towards orbit. At about five and three-quarter minutes into ascent, the orbiter’s direct communication links with the ground began to fade, at which point it rolled heads up to reroute its communication links to the Tracking and Data Relay Satellite system.

At about seven and a half minutes into ascent, the mass of the vehicle was low enough that the engines had to be throttled back to limit vehicle acceleration to 3 g (29.4m/s or 96.5ft/s, equivalent to accelerating from zero to 105.9km/h (65.8mph) in a second). The Shuttle would maintain this acceleration for the next minute, and main engine cut-off (MECO) occurred at about eight and a half minutes after launch.[79] The main engines were shut down before complete depletion of propellant, as running dry would have destroyed the engines. The oxygen supply was terminated before the hydrogen supply, as the SSMEs reacted unfavorably to other shutdown modes. (Liquid oxygen has a tendency to react violently, and supports combustion when it encounters hot engine metal.) A few seconds after MECO, the external tank was released by firing pyrotechnic fasteners.

At this point the Shuttle and external tank were on a slightly suborbital trajectory, coasting up towards apogee. Once at apogee, about half an hour after MECO, the Shuttle’s Orbital Maneuvering System (OMS) engines were fired to raise its perigee and achieve orbit, while the external tank fell back into the atmosphere and burned up over the Indian Ocean or the Pacific Ocean depending on launch profile.[65] The sealing action of the tank plumbing and lack of pressure relief systems on the external tank helped it break up in the lower atmosphere. After the foam burned away during re-entry, the heat caused a pressure buildup in the remaining liquid oxygen and hydrogen until the tank exploded. This ensured that any pieces that fell back to Earth were small.

The Shuttle was monitored throughout its ascent for short range tracking (10 seconds before liftoff through 57 seconds after), medium range (7 seconds before liftoff through 110 seconds after) and long range (7 seconds before liftoff through 165 seconds after). Short range cameras included 22 16mm cameras on the Mobile Launch Platform and 8 16mm on the Fixed Service Structure, 4 high speed fixed cameras located on the perimeter of the launch complex plus an additional 42 fixed cameras with 16mm motion picture film. Medium range cameras included remotely operated tracking cameras at the launch complex plus 6 sites along the immediate coast north and south of the launch pad, each with 800mm lens and high speed cameras running 100 frames per second. These cameras ran for only 410 seconds due to limitations in the amount of film available. Long range cameras included those mounted on the external tank, SRBs and orbiter itself which streamed live video back to the ground providing valuable information about any debris falling during ascent. Long range tracking cameras with 400-inch film and 200-inch video lenses were operated by a photographer at Playalinda Beach as well as 9 other sites from 38 miles north at the Ponce Inlet to 23 miles south to Patrick Air Force Base (PAFB) and additional mobile optical tracking camera was stationed on Merritt Island during launches. A total of 10 HD cameras were used both for ascent information for engineers and broadcast feeds to networks such as NASA TV and HDNet. The number of cameras significantly increased and numerous existing cameras were upgraded at the recommendation of the Columbia Accident Investigation Board to provide better information about the debris during launch. Debris was also tracked using a pair of Weibel Continuous Pulse Doppler X-band radars, one on board the SRB recovery ship MV Liberty Star positioned north east of the launch pad and on a ship positioned south of the launch pad. Additionally, during the first 2 flights following the loss of Columbia and her crew, a pair of NASA WB-57 reconnaissance aircraft equipped with HD Video and Infrared flew at 60,000 feet (18,000m) to provide additional views of the launch ascent.[80] Kennedy Space Center also invested nearly $3million in improvements to the digital video analysis systems in support of debris tracking.[81]

Once in orbit, the Shuttle usually flew at an altitude of 320km (170nmi) and occasionally as high as 650km (350nmi).[82] In the 1980s and 1990s, many flights involved space science missions on the NASA/ESA Spacelab, or launching various types of satellites and science probes. By the 1990s and 2000s the focus shifted more to servicing the space station, with fewer satellite launches. Most missions involved staying in orbit several days to two weeks, although longer missions were possible with the Extended Duration Orbiter add-on or when attached to a space station.

Almost the entire Space Shuttle re-entry procedure, except for lowering the landing gear and deploying the air data probes, was normally performed under computer control. However, the re-entry could be flown entirely manually if an emergency arose. The approach and landing phase could be controlled by the autopilot, but was usually hand flown.

The vehicle began re-entry by firing the Orbital maneuvering system engines, while flying upside down, backside first, in the opposite direction to orbital motion for approximately three minutes, which reduced the Shuttle’s velocity by about 200mph (322km/h). The resultant slowing of the Shuttle lowered its orbital perigee down into the upper atmosphere. The Shuttle then flipped over, by pushing its nose down (which was actually “up” relative to the Earth, because it was flying upside down). This OMS firing was done roughly halfway around the globe from the landing site.

The vehicle started encountering more significant air density in the lower thermosphere at about 400,000ft (120km), at around Mach 25, 8,200m/s (30,000km/h; 18,000mph). The vehicle was controlled by a combination of RCS thrusters and control surfaces, to fly at a 40-degree nose-up attitude, producing high drag, not only to slow it down to landing speed, but also to reduce reentry heating. As the vehicle encountered progressively denser air, it began a gradual transition from spacecraft to aircraft. In a straight line, its 40-degree nose-up attitude would cause the descent angle to flatten-out, or even rise. The vehicle therefore performed a series of four steep S-shaped banking turns, each lasting several minutes, at up to 70 degrees of bank, while still maintaining the 40-degree angle of attack. In this way it dissipated speed sideways rather than upwards. This occurred during the ‘hottest’ phase of re-entry, when the heat-shield glowed red and the G-forces were at their highest. By the end of the last turn, the transition to aircraft was almost complete. The vehicle leveled its wings, lowered its nose into a shallow dive and began its approach to the landing site.

Simulation of the outside of the Shuttle as it heats up to over 1,500C during re-entry.

A Space Shuttle model undergoes a wind tunnel test in 1975. This test is simulating the ionized gasses that surround a Shuttle as it reenters the atmosphere.

A computer simulation of high velocity air flow around the Space Shuttle during re-entry.

The orbiter’s maximum glide ratio/lift-to-drag ratio varies considerably with speed, ranging from 1:1 at hypersonic speeds, 2:1 at supersonic speeds and reaching 4.5:1 at subsonic speeds during approach and landing.[83]

In the lower atmosphere, the orbiter flies much like a conventional glider, except for a much higher descent rate, over 50m/s (180km/h; 110mph) or 9,800 fpm. At approximately Mach 3, two air data probes, located on the left and right sides of the orbiter’s forward lower fuselage, are deployed to sense air pressure related to the vehicle’s movement in the atmosphere.

When the approach and landing phase began, the orbiter was at a 3,000m (9,800ft) altitude, 12km (7.5mi) from the runway. The pilots applied aerodynamic braking to help slow down the vehicle. The orbiter’s speed was reduced from 682 to 346km/h (424 to 215mph), approximately, at touch-down (compared to 260km/h or 160mph for a jet airliner). The landing gear was deployed while the Orbiter was flying at 430km/h (270mph). To assist the speed brakes, a 12m (39ft) drag chute was deployed either after main gear or nose gear touchdown (depending on selected chute deploy mode) at about 343km/h (213mph). The chute was jettisoned once the orbiter slowed to 110km/h (68.4mph).

Media related to Landings of space Shuttles at Wikimedia Commons

After landing, the vehicle stayed on the runway for several hours for the orbiter to cool. Teams at the front and rear of the orbiter tested for presence of hydrogen, hydrazine, monomethylhydrazine, nitrogen tetroxide and ammonia (fuels and by-products of the reaction control system and the orbiter’s three APUs). If hydrogen was detected, an emergency would be declared, the orbiter powered down and teams would evacuate the area. A convoy of 25 specially designed vehicles and 150 trained engineers and technicians approached the orbiter. Purge and vent lines were attached to remove toxic gases from fuel lines and the cargo bay about 4560 minutes after landing. A flight surgeon boarded the orbiter for initial medical checks of the crew before disembarking. Once the crew left the orbiter, responsibility for the vehicle was handed from the Johnson Space Center back to the Kennedy Space Center.[84]

If the mission ended at Edwards Air Force Base in California, White Sands Space Harbor in New Mexico, or any of the runways the orbiter might use in an emergency, the orbiter was loaded atop the Shuttle Carrier Aircraft, a modified 747, for transport back to the Kennedy Space Center, landing at the Shuttle Landing Facility. Once at the Shuttle Landing Facility, the orbiter was then towed 2 miles (3.2km) along a tow-way and access roads normally used by tour buses and KSC employees to the Orbiter Processing Facility where it began a months-long preparation process for the next mission.[84]

NASA preferred Space Shuttle landings to be at Kennedy Space Center.[85] If weather conditions made landing there unfavorable, the Shuttle could delay its landing until conditions are favorable, touch down at Edwards Air Force Base, California, or use one of the multiple alternate landing sites around the world. A landing at any site other than Kennedy Space Center meant that after touchdown the Shuttle must be mated to the Shuttle Carrier Aircraft and returned to Cape Canaveral. Space Shuttle Columbia (STS-3) once landed at the White Sands Space Harbor, New Mexico; this was viewed as a last resort as NASA scientists believed that the sand could potentially damage the Shuttle’s exterior.

There were many alternative landing sites that were never used.[86][87]

An example of technical risk analysis for a STS mission is SPRA iteration 3.1 top risk contributors for STS-133:[88][89]

An internal NASA risk assessment study (conducted by the Shuttle Program Safety and Mission Assurance Office at Johnson Space Center) released in late 2010 or early 2011 concluded that the agency had seriously underestimated the level of risk involved in operating the Shuttle. The report assessed that there was a 1 in 9 chance of a catastrophic disaster during the first nine flights of the Shuttle but that safety improvements had later improved the risk ratio to 1 in 90.[90]

Below is a list of major events in the Space Shuttle orbiter fleet.

Sources: NASA launch manifest,[94] NASA Space Shuttle archive[95]

On January 28, 1986, Challenger disintegrated 73 seconds after launch due to the failure of the right SRB, killing all seven astronauts on board. The disaster was caused by low-temperature impairment of an O-ring, a mission critical seal used between segments of the SRB casing. Failure of the O-ring allowed hot combustion gases to escape from between the booster sections and burn through the adjacent external tank, causing it to explode.[96] Repeated warnings from design engineers voicing concerns about the lack of evidence of the O-rings’ safety when the temperature was below 53F (12C) had been ignored by NASA managers.[97]

On February 1, 2003, Columbia disintegrated during re-entry, killing its crew of seven, because of damage to the carbon-carbon leading edge of the wing caused during launch. Ground control engineers had made three separate requests for high-resolution images taken by the Department of Defense that would have provided an understanding of the extent of the damage, while NASA’s chief thermal protection system (TPS) engineer requested that astronauts on board Columbia be allowed to leave the vehicle to inspect the damage. NASA managers intervened to stop the Department of Defense’s assistance and refused the request for the spacewalk,[98] and thus the feasibility of scenarios for astronaut repair or rescue by Atlantis were not considered by NASA management at the time.[99]

NASA retired the Space Shuttle in 2011, after 30 years of service. The Shuttle was originally conceived of and presented to the public as a “Space Truck”, which would, among other things, be used to build a United States space station in low earth orbit in the early 1990s. When the US space station evolved into the International Space Station project, which suffered from long delays and design changes before it could be completed, the retirement of the Space Shuttle was delayed several times until 2011, serving at least 15 years longer than originally planned. Discovery was the first of NASA’s three remaining operational Space Shuttles to be retired.[100]

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Space Adventures, Ltd. | Zero Gravity Flight

Aboard a specially modified Boeing 727-200, G-FORCE ONE, weightlessness is achieved by doing aerobatic maneuvers known as parabolas. Specially trained pilots perform these aerobatic maneuvers which are not simulated in any way. ZERO-G passengers experience true weightlessness.

Before starting a parabola, G-FORCE ONEflies level to the horizon at an altitude of 24,000 feet. The pilots then begins to pull up, gradually increasing the angle of the aircraft to about 45 to the horizon reaching an altitude of 34,000 feet. During this pull-up, passengers will feel the pull of 1.8 Gs. Next the plane is pushed over to create the zero gravity segment of the parabola. For the next 20-30 seconds everything in the plane is weightless. Next a gentle pull-out is started which allows the flyers to stabilize on the aircraft floor. This maneuver is repeated 12-15 times, each taking about ten miles of airspace to perform.

In addition to achieving zero gravity, G-FORCE ONEalso flies a parabola designed to offer Lunar gravity (one sixth your weight)and Martian gravity (one third your weight). This is created by flying a larger arc over the top of the parabola.

G-FORCE ONEflies in a FAA designated airspace that is approximately 100 miles long and ten miles wide. Usually three to five parabolas are flown consecutively with short periods of level flight between each set.

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Space Adventures, Ltd. | Zero Gravity Flight

Space Adventures, Ltd. | Zero Gravity Flight

Aboard a specially modified Boeing 727-200, G-FORCE ONE, weightlessness is achieved by doing aerobatic maneuvers known as parabolas. Specially trained pilots perform these aerobatic maneuvers which are not simulated in any way. ZERO-G passengers experience true weightlessness.

Before starting a parabola, G-FORCE ONEflies level to the horizon at an altitude of 24,000 feet. The pilots then begins to pull up, gradually increasing the angle of the aircraft to about 45 to the horizon reaching an altitude of 34,000 feet. During this pull-up, passengers will feel the pull of 1.8 Gs. Next the plane is pushed over to create the zero gravity segment of the parabola. For the next 20-30 seconds everything in the plane is weightless. Next a gentle pull-out is started which allows the flyers to stabilize on the aircraft floor. This maneuver is repeated 12-15 times, each taking about ten miles of airspace to perform.

In addition to achieving zero gravity, G-FORCE ONEalso flies a parabola designed to offer Lunar gravity (one sixth your weight)and Martian gravity (one third your weight). This is created by flying a larger arc over the top of the parabola.

G-FORCE ONEflies in a FAA designated airspace that is approximately 100 miles long and ten miles wide. Usually three to five parabolas are flown consecutively with short periods of level flight between each set.

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Space Adventures, Ltd. | Zero Gravity Flight

Spaceflight Now The leading source for online space news

The White Houses $19.9 billion NASA budget outline released Monday would continue development of NASAs heavy-lift Space Launch System rocket and Orion crew capsule and begin the deployment of a mini-space station around the moon as soon as 2022, but the proposal would cancel WFIRST, a flagship-class astronomy mission planned for launch in the mid-2020s.

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Spaceflight Now The leading source for online space news

Marshall Space Flight Center – Wikipedia

Coordinates: 343849N 864027W / 34.64688N 86.67416W / 34.64688; -86.67416

The George C. Marshall Space Flight Center (MSFC), located in Huntsville, Alabama, is the U.S. government’s civilian rocketry and spacecraft propulsion research center.[1] The largest NASA center, MSFC’s first mission was developing the Saturn launch vehicles for the Apollo moon program. Marshall has been the agency’s lead center for Space Shuttle propulsion and its external tank; payloads and related crew training; International Space Station (ISS) design and assembly; and computers, networks, and information management. Located on the Redstone Arsenal near Huntsville, Alabama, MSFC is named in honor of General of the Army George Marshall.

The center also contains the Huntsville Operations Support Center (HOSC), a facility that supports ISS launch, payload and experiment activities at the Kennedy Space Center. The HOSC also monitors rocket launches from Cape Canaveral Air Force Station when a Marshall Center payload is on board.

After the end of the war with Germany in May 1945, a program was initiated to bring to the United States a number of scientists and engineers who had been at the center of Germany’s advanced military technologies. The largest and best-known activity was called Operation Paperclip. In August 1945, 127 missile specialists led by Wernher von Braun signed work contracts with the U.S. Army’s Ordnance Corps. Most of them had worked on the V-2 missile development under von Braun at Peenemnde. Von Braun and the other Germans were sent to Fort Bliss, Texas, joining the Army’s newly formed Research and Development Division Sub-office (Rocket).

For the next five years, von Braun and the German scientists and engineers were primarily engaged in adapting and improving the V-2 missile for U.S. applications; testing was conducted at nearby White Sands Proving Grounds, New Mexico. Von Braun had long had a great interest in rocketry for space science and exploration. Toward this, he was allowed to use a WAC Corporal rocket as a second stage for a V-2; the combination, called Bumper, reached a record-breaking 250 miles (400km) altitude.[2]

During World War II, the production and storage of ordnance shells was conducted by three arsenals nearby to Huntsville, Alabama. After the war, these were closed, and the three areas were combined to form Redstone Arsenal. In October 1948, the Chief of Ordnance designated Redstone Arsenal as the center of research and development activities in free-flight rockets and related items, and the following June, the Ordnance Rocket Center was opened. A year later, the Secretary of the Army approved the transfer of the rocket research and development activities from Fort Bliss to the new center at Redstone Arsenal. Beginning in April 1950, about 1,000 persons were involved in the transfer, including von Braun’s group. At this time, R&D responsibility for guided missiles was added, and studies began on a medium-range guided missile that eventually became the Redstone rocket.

Over the next decade, the missile development on Redstone Arsenal greatly expanded. Many small free-flight and guided rockets were developed, and work on the Redstone rocket got underway. Although this rocket was primarily intended for military purposes, von Braun kept space firmly in his mind, and published a widely read article on this subject.[3] In mid-1952, the Germans who had initially worked under individual contracts were converted to civil service employees, and in 1954-55, most became U.S. citizens. Von Braun was appointed Chief of the Guided Missile Development Division.[4]

In September 1954, von Braun proposed using the Redstone as the main booster of a multi-stage rocket for launching artificial satellites. A year later, a study for Project Orbiter was completed, detailing plans and schedules for a series of scientific satellites. The Army’s official role in the U.S. space satellite program was delayed, however, after higher authorities elected to use the Vanguard rocket then being developed by the Naval Research Laboratory (NRL).

In February 1956, the Army Ballistic Missile Agency (ABMA) was established; von Braun was the director of the Development Operations Division. One of the primary programs was a 1,500-mile (2,400km), single-stage missile that was started the previous year; intended for both the U.S. Army and U.S. Navy, this was designated the PGM-19 Jupiter. Guidance component testing for this Jupiter intermediate range ballistic missile (IRBM) began in March 1956 on a modified Redstone missile dubbed Jupiter A while re-entry vehicle testing began in September 1956 on a Redstone with spin-stabilized upper stages named Jupiter-C. The first Jupiter IRBM flight took place from Cape Canaveral in March 1957 with the first successful flight to full range on 31 May.[5] Jupiter was eventually taken over by the U.S. Air Force. The ABMA developed Jupiter-C was composed of a Redstone rocket first stage and two upper stages for RV tests or three upper stages for Explorer satellite launches. ABMA had originally planned the 20 September 1956 flight as a satellite launch but, by direct intervention of Eisenhower, was limited to the use of 2 upper stages for an RV test flight traveling 3,350 miles (5,390km) and attaining an altitude of 682 miles (1,098km). While the Jupiter C capability was such that it could have placed the fourth stage in orbit, that mission had been assigned to the NRL.[6][7] Later Jupiter-C flights would be used to launch satellites.

The Soviet Union launched Sputnik 1, the first man-made earth satellite, on October 4, 1957. This was followed on November 3 with the second satellite, Sputnik 2. The United States attempted a satellite launch on December 6, using the NRL’s Vanguard rocket, but it barely struggled off the ground, then fell back and exploded. On January 31, 1958, after finally receiving permission to proceed, von Braun and the ABMA space development team used a Jupiter C in a Juno I configuration (addition of a fourth stage) to successfully place Explorer 1, the first American satellite, into orbit around the earth.

Effective at the end of March 1958, the U.S. Army Ordnance Missile Command (AOMC), was established at Redstone Arsenal. This encompassed the ABMA and its newly operational space programs. In August, AOMC and Advanced Research Projects Agency (ARPA, a Department of Defense organization) jointly initiated a program managed by ABMA to develop a large space booster of approximately 1.5-million-pounds thrust using a cluster of available rocket engines. In early 1959, this vehicle was designated Saturn.

On April 2, President Dwight D. Eisenhower recommended to Congress that a civilian agency be established to direct nonmilitary space activities, and on July 29, the President signed the National Aeronautics and Space Act, creating the National Aeronautics and Space Administration (NASA). The nucleus for forming NASA was the National Advisory Committee for Aeronautics (NACA), with its 7,500 employees and Ames Research Center (ARC), Langley Research Center (LaRC), and Lewis Flight Propulsion Laboratory (later LRC, then Glenn RC) becoming the initial operations of NASA.

Despite the existence of an official space agency, the Army continued with certain far-reaching space programs. In June 1959, a secret study on Project Horizon was completed by ABMA, detailing plans for using the Saturn booster in establishing a manned Army outpost on the moon. Project Horizon, however, was rejected, and the Saturn program was transferred to NASA.

The U.S. manned satellite space program, using the Redstone as a booster, was officially named Project Mercury on November 26, 1958. With a future goal of manned flight, monkeys Able and Baker were the first living creatures recovered from outer space on May 28, 1959. They had been carried in the nose cone on a Jupiter missile to an altitude of 300 miles (480km) and a distance of 1,500 miles (2,400km), successfully withstanding 38 times the normal pull of gravity. Their survival during speeds over 10,000 miles per hour was America’s first biological step toward putting a man into space.

On October 21, 1959, President Eisenhower approved the transfer of all Army space-related activities to NASA. This was accomplished effective July 1, 1960, when 4,670 civilian employees, about $100 million worth of buildings and equipment, and 1,840 acres (7.4km2) of land transferred from AOMC/ABMA to NASA’s George C. Marshall Space Flight Center. MSFC officially opened at Redstone Arsenal on this same date, then was dedicated on September 8 by President Eisenhower in person. The Center was named in honor of General of the Army George C. Marshall, Army Chief of Staff during World War II, United States Secretary of State, and Nobel Prize winner for his world-renowned Marshall Plan.

From its initiation, MSFC has been NASA’s lead center for the development of rocket propulsion systems and technologies. During the 1960s, the activities were largely devoted to the Apollo Program man’s first visit to the Moon. In this, the Saturn Family of launch vehicles were designed and tested at MSFC. Following the highly successful Moon landing, including initial scientific exploration, MSFC had a major role in Post-Apollo activities; this included Skylab, the United States’ first space station. With a permanent space station as an objective, the Space Shuttle was developed as a reusable transportation vehicle, and with it came Spacelab and other experimental activities making use of the Shuttle cargo bay. These and other projects are described in a later section. But first, MSFC’s present capabilities and projects are addressed.

Marshall Space Flight Center has capabilities and projects supporting NASA’s mission in three key areas: lifting from Earth (Space Vehicles), living and working in space (International Space Station), and understanding our world and beyond (Advanced Scientific Research).[8]

MSFC is NASA’s designated developer and integrator of launch systems. The state-of-the-art Propulsion Research Laboratory serves as a leading national resource for advanced space propulsion research. Marshall has the engineering capabilities to take space vehicles from initial concept to sustained service. For manufacturing, the world’s largest-known welding machine of its type was installed at MSFC in 2008; it is capable of building major, defect-free components for manned-rated space vehicles.

In early March 2011, NASA Headquarters announced that MSFC will lead the efforts on a new heavy-lift rocket that, like the Saturn V of the lunar exploration program of the late 1960s, will carry large, man-rated payloads beyond low-Earth orbit. The Center will have the program office for what is being called the Space Launch System (SLS).[9]

Before it was cancelled by President Barack Obama in early 2010, the Constellation Program had been a major activity in NASA since 2004. In this program, MSFC was responsible for propulsion on the heavy-lift vehicles. These vehicles were designated Ares I and Ares V, and would replace the aging Space Shuttle fleet as well as transport humans to the Moon, Mars, and other deep-space destinations.[10]

Starting in 2006, the MSFC Exploration Launch Projects Office began work on the Ares projects. On October 28, 2009, an Ares I-X test rocket lifted off from the newly modified Launch Complex 39B at Kennedy Space Center (KSC) for a two-minute powered flight; then continued for four additional minutes traveling 150 miles (240km) down range.

MSFC had responsibility for the Space Shuttle’s propulsion engines. On February 1, 2003, the Space Shuttle Columbia disaster occurred, with the orbiter disintegrating during reentry and resulting in the death of its seven crew members. Flights of the other Shuttles were put on hold for 29 months. Based on a seven-month investigation, including a ground search that recovered debris from about 38 percent of the Orbiter, together with telemetry data and launch films, indicated that the failure was caused by a piece of insulation that broke off the external tank during launch and damaged the thermal protection on the Orbiter’s left wing.

MSFC was responsible for the external tank, but few or no changes to the tank were made; rather, NASA decided that it was inevitable that some insulation might be lost during launch and thus required that an inspection of the orbiter’s critical elements be made prior to reentry on future flights.

NASA retired the Space Shuttle in 2011, leaving America dependent upon the Russian Soyuz spacecraft for manned space missions.

The initial plans for the Space Station envisaged a small, low-cost Crew Return Vehicle (CRV) that would provide emergency evacuation capability. The 1986 Challenger disaster led planners to consider a more capable spacecraft. The Orbital Space Plane (OSP) development got underway in 2001, with an early version expected to enter service by 2010. With the initiation of the Constellation program in 2004, the knowledge gained on the OSP was transferred to Johnson Space Center (JSC) for use in the development of the Crew Exploration Vehicle. No operational OSP was ever built.[11]

The International Space Station is a partnership of the United States, Russian, European, Japanese, and Canadian Space Agencies. The station has continuously had human occupants since November 2, 2000. Orbiting 16 times daily at an average altitude of about 250mi (400km), it passes over some 90 percent of the world’s surface. It weighs over 800,000 pounds (360,000kg), and a crew of six conducts research and prepares the way for future explorations.

NASA began the plan to build a space station in 1984. The station was named Freedom in 1988, and changed to the International Space Station (ISS) in 1992. The ISS is composed in modules, and the assembly in orbit started with the delivery of Russian module Zarya in November 1998. This was followed in December by the first U.S. module, Unity also called Node 1, built by Boeing in facilities at MSFC.[12]

As the 21st century started, Space Shuttle flights carried up supplies and additional small equipment, including a portion of the solar power array. The two-module embryonic ISS remained unmanned until the next module, Destiny, the U.S. Laboratory, arrived on February 7, 2001; this module was also built by Boeing at MSFC. The three-module station allowed a minimum crew of two astronauts or cosmonauts to be on the ISS permanently. In July, Quest air-lock was added to Unity, providing the capability for extra-vehicular activity (EVA).

Since 1998, 18 major U.S. components on the ISS have been assembled in space. In October 2007, Harmony or Node 2, was attached to Destiny; also managed by MSFC, this gave connection hubs for European and Japanese modules as well as additional living space, allowing the ISS crew to increase to six. The 18th and final major U.S. and Boeing-built element, the Starboard 6 Truss Segment, was delivered to the ISS in February 2009. With this, the full set of solar arrays could be activated, increasing the power available for science projects to 30kW. That marked the completion of the U.S. “core” of the station.

On 5 March 2010, Boeing turned over to NASA the U.S. on-orbit segment of the ISS.[13] It is planned that the International Space Station will be operated at least through the end of 2020. With the retirement of the Space Shuttle fleet in 2011, future manned missions to the ISS will depend upon the Russian Soyuz spacecraft for the immediate future.

MSFC is involved in some of the most advanced space research of our time. Scientist/Astronaut researchers aboard the International Space Station are engaged in hundreds of advanced experiments, most of which could not be conducted except for the zero-gravity environment. The deep-space images from the Hubble Space Telescope and the Chandra X-ray Observatory are made possible in part by the people and facilities at Marshall. The Center was not only responsible for the design, development, and construction of these telescopes, but it is also now home to the only facility in the world for testing large telescope mirrors in a space-simulated environment. Preliminary work has started on a Hubble successor, the James Webb Space Telescope (JWST); this will be the largest primary mirror ever assembled in space. In the future, the facility will likely be used for another successor, the Advanced Technology Large-Aperture Space Telescope (AT-LAST).

The National Space Science and Technology Center (NSSTC) is a joint research venture between NASA and the seven research universities of the State of Alabama. The primary purpose of NSSTC is to foster collaboration in research between government, academia, and industry. It consists of seven research centers: Advanced Optics, Biotechnology, Global Hydeology & Climate, Information Technology, Material Science, Propulsion, and Space Science. Each center is managed by either MSFC, the host NASA facility, or the University of Alabama in Huntsville, the host university.

The Hubble Space Telescope was launched in April 1990, but gave flawed images. It had been designed at MSFC, but used a primary mirror that had spherical aberration due to incorrect grinding and polishing by the contractor. The defect was found when the telescope was in orbit. The design was such that repairs were possible, and three maintenance missions were flown in Shuttles during the 1990s. Another servicing mission (STS-109) was flown on March 1, 2002. Each mission resulted in considerable improvements, with the images receiving worldwide attention from astronomers as well as the public.

Based on the success of earlier maintenance missions, NASA decided to have a fifth service mission to Hubble; this was STS-125 flown on May 11, 2009. The maintenance and addition of equipment resulted in Hubble performance considerably better than planned at its origin. It is now expected that the Hubble will remain operational until its successor, the James Webb Space Telescope (JWST), is available in 2018.[14][15]

The Chandra X-ray Observatory, originating at MSFC, was launched on July 3, 1999, and is operated by the Smithsonian Astrophysical Observatory. With an angular resolution of 0.5 arcsecond (2.4 rad), it has a thousand times better resolution than the first orbiting X-ray telescopes. Its highly eliptical orbit allows continuous observations up to 85 percent of its 65-hour orbital period. With its ability to make X-ray images of star clusters, supernova remnants, galactic eruptions, and collisions between clusters of galaxies – in its first decade of operation it has transformed astronomer’s view of the high-energy universe.[16]

The Fermi Gamma-ray Space Telescope, initially called the Gamma-Ray Large Area Space Telescope (GLAST), is an international, multi-agency space observatory used to study the cosmos. It was launched June 11, 2008, has a design life of 5 years and a goal of 10 years. The primary instrument is the Large Area Telescope (LAT) that is sensitive in the photon energy range of 8 to greater than 300 GeV. It can view about 20% of the sky at any given moment.[17]

The LAT is complemented by the GLAST Burst Monitor (GBM) which can detect burst of X-rays and gamma rays in the 8-keV to 3-MeV energy range, overlapping with the LAT. The GBM is a collaborative effort between the U.S. National Space Science and Technology Center and the Max Planck Institute for Extraterrestrial Physics in Germany. MSFC manages the GBM, and Charles A. Meegan of MSFC is the Principal Investigator. Many new discoveries have been made in the initial period of operation. For example, on May 10, 2009, a burst was detected that, by its propagation characteristics, is believed to negate some approaches to a new theory of gravity.[18]

The Burst and Transient Source Experiment (BATSE), with Gerald J. Fishman of MSFC serving as Principal Investigator, is an ongoing examination of the many years of data from gamma-ray bursts, pulsars, and other transient gamma-ray phenomena.[19] The 2011 Shaw Prize, often called “Asia’s Nobel Prize,” was shared by Fishman and Italian astronomer Enrico Costa for their gamma-ray research.[20]

For 10 years, MSFC has supported activities in the U.S. Laboratory (Destiny) and elsewhere on the International Space Station through the Payload Operations Center (POC). The research activities include experiments on topics ranging from human physiology to physical science. Operating around the clock, scientists, engineers, and flight controllers in the POC link Earth-bound researchers throughout the world with their experiments and astronauts aboard the ISS. As of March2011[update], this has included the coordination of more than 1,100 experiments conducted by 41 space-station crew members involved in over 6,000 hours of science research.

Teams at Marshall manage NASA’s programs for exploring the Sun, the Moon, the planets, and other bodies throughout our solar system. These have included Gravity Probe B, an experiment to test two predictions of Einstein’s general theory of relativity, and Solar-B, an international mission to study the solar magnetic field and origins of the solar wind, a phenomenon that affects radio transmission on the Earth. The MSFC Lunar Precursor and Robotic Program Office manages projects and directs studies on lunar robotic activities across NASA.

MSFC also develops systems for monitoring the Earth’s climate and weather patterns. At the Global Hydrology and Climate Center (GHCC), researchers combine data from Earth systems with satellite data to monitor biodiversity conservation and climate change, providing information that improves agriculture, urban planning, and water-resource management.[21]

On November 19, 2010, MSFC entered the new field of microsatellites with the successful launch of FASTSAT (Fast, Affordable, Science and Technology Satellite). Part of a joint DoD/NASA payload, it was launched by a Minotaur IV rocket from the Kodiak Launch Complex on Kodiak Island, Alaska. FASTSAT is a platform carrying multiple small payloads to low-Earth orbit, creating opportunities to conduct low-cost scientific and technology research on an autonomous satellite in space. FASTSAT, weighing just under 400 pounds (180kg), serves as a full scientific laboratory containing all the resources needed to carry out scientific and technology research operations. It was developed at the MSFC in partnership with the Von Braun Center for Science & Innovation and Dynetics, Inc., both of Huntsville, Alabama. Mark Boudreaux is the project manager for MSFC.

There are six experiments on the FASTSAT bus, including NanoSail-D2, which is itself a nanosatellite the first satellite launched from another satellite. It was deployed satisfactorily on January 21, 2011.[22]

In addition to supporting NASA’s key missions, the spinoffs from these activities at MSFC have contributed broadly to technologies that improve the Nation and the World. In the last decade alone, Marshall generated more than 60 technologies featured as NASA spinoffs. MSFC research has benefited firefighters, farmers, plumbers, healthcare providers, soldiers, teachers, pilots, divers, welders, architects, photographers, city planners, disaster relief workers, criminal investigators, and even video-gamers and golfers.[23]

The Space Shuttle is likely the most complex spacecraft ever built. Although MSFC was not responsible for developing the centerpiece the Orbiter Vehicle (OV) it was responsible for all of the rocket propulsion elements: the OV’s three main engines, the External Tank (ET), and the Solid-Rocket Boosters (SRBs). MSFC was also responsible for Spacelab, the research facility carried in the Shuttle’s cargo bay on certain flights. From the start of the program in 1972, the management and development of Space Shuttle propulsion was a major activity at MSFC. Alex A. McCool, Jr. was manager of MSFC’s Space Shuttle Projects Office.

Throughout 1980, engineers at MSFC participated in tests related to plans to launch the first Space Shuttle. During these early tests and prior to each later Shuttle launch, personnel in the Huntsville Operations Support Center monitored consoles to evaluate and help solve any problems at the Florida launch that might involve Shuttle propulsion

On April 12, 1981, Columbia made the first orbital test flight of a full Space Shuttle with two astronauts. This was designated STS-1 (Space Transportation System-1), and verified the combined performance of the entire system. This was followed by STS-2 on November 12, also using Columbia, primarily to demonstrate safe re-launch of a Shuttle. During 1982, two more test flights (STS-3 & STS-4) were made. STS-5, launched November 11, was the first operational mission; carrying four astronauts, two commercial satellite were deployed. In all three of these flights, on-board experiments were carried and conducted on pallets in the Shuttle’s cargo bay.[24]

Space Shuttle Challenger was launched on mission STS-51-L on January 28, 1986. (The sequential numbering changed after 1983, but otherwise this would have been STS-25). One-minute, 13-seconds into flight, the entire Challenger was enveloped in a fireball and broke into several large segments, killing the seven astronauts. Subsequent analysis of the high-speed tracking films and telemetry signals indicated that a leak occurred in a joint on one of the solid rocket boosters (SRBs), the escaping flame impinged on the surface of the external tank (ET); there followed a complex series of very rapid structural failures, and in milliseconds the hydrogen and oxygen streaming from the ruptured tank exploded.

The basic cause of the disaster was determined to be an O-ring failure in the right SRB; cold weather was a contributing factor. The redesign effort, directed by MSFC, involved an extensive test program to verify that the SRBs were safe. There were no Space Shuttle missions in the remainder of 1986 or in 1987. Flights resumed in September 1988, with sequential numbering starting with STS-26.

As a reusable space-launch vehicle, the space shuttles carried a wide variety of payloads from scientific research equipment to highly classified military satellites. The flights were assigned a Space Transportation System (STS) number, in general sequenced by the planned launch date. The Wikipedia list of space shuttle missions shows all flights, their missions, and other information.

The first orbital flight (STS-1) by Shuttle Columbia on April 12, 1981, did not have a payload, but all flights that followed generally had multiple payloads. Through 1989, there were 32 flights; this includes the one on January 28, 1986, when Challenger was lost, and the delay until September 29, 1988, when flights resumed. During the 1990s, there were 58 flights, giving a total of 95 successful flights through 1999.[25]

For the Magellan planetary spacecraft, MSFC managed the adaptation of the Inertial Upper Stage. This solid-rocket was used in May 1989 to propel the spacecraft from Orbiter Atlantis on a 15-month loop around the Sun and eventually into orbit around Venus for four years of radar surface-mapping.

Many Shuttle flights carried equipment for performing on-board research. Such equipment was accommodated in two forms: on pallets or other arrangements in the Shuttle’s cargo bay (most often in addition to hardware for the primary mission), or within a reusable laboratory called Skylab. All such experimental payloads were under the general responsibility of MSFC.

Pallet experiments covered a very wide spread of types and complexity, but many of them were in fluid physics, materials science, biotechnology, combustion science, and commercial space processing. For some missions, an aluminum bridge fitting across the cargo bay was used. This could carry 12 standard canisters holding isolated experiments, particularly those under the Getaway Special (GAS) program. GAS flights were made available at low cost to colleges and universities, American industries, individuals, foreign governments, and others.

On some flights, a variety of pallet experiments constituted the full payload; examples of these include the following:

In addition to the pallet experiments, many other experiments were flown and performed using Spacelab. This was a reusable laboratory consisting of multiple components, including a pressurized module, an unpressurized carrier, and other related hardware. Under a program managed by MSFC, ten Europeans nations jointly designed, built, and financed the first Spacelab through the European Space Research Organisation (ESRO. In addition, Japan funded a Spacelab for STS-47, a dedicated mission.[26]

Over a 15-year period, Spacelab components flew on 22 shuttle missions, the last in April 1998. Examples of Spacelab missions follow:

In early 1990, MSFC’s new Spacelab Mission Operations Control Center took over the responsibility for controlling all Spacelab missions. This replaced the Payload Operations Control Center formerly situated at the JSC from which previous Spacelab missions were operated.[27]

The advent of the Space Shuttle made possible several major space programs in which MSFC had significant responsibilities. These were the International Space Station, the Hubble Space Telescope, the Chandra X-Ray Observatory, and the Compton Gamma-Ray Observatory. The latter three are part of NASA’s series of Great Observatories; this series also includes the Spitzer Space Telescope, but this was not launched by a Space Shuttle and MSFC had no significant role in its development.

A manned space station had long been in the plans of visionaries. Wernhar von Braun, in his widely read Collier’s Magazine 1953 article, envisioned this to be a huge wheel, rotating to produce gravity-like forces on the occupants.[28] In Project Horizon, prepared by the U.S. Army in 1959, a space station would be built by assembling spent booster rockets. Following this same basic concept, in 1973 MSFC used a modified stage of Saturn V to put into orbit Skylab, but this was preceded by the Soviet Union’s Salyut in 1971, then followed by their Mir in 1986. Even during Skylab, MSFC began plans for a much more complete space station. President Ronald Reagan announced plans to build Space Station Freedom in 1984. Luther B. Powell was MSFC’s space station program manager.

By the late 1990s, planning for four different stations were underway: the American Freedom, the Soviet/Russian Mir-2, the European Columbus, and the Japanese Kib. In June 1992, with the Cold War over, American President George H. W. Bush and Russian President Boris Yeltsin agreed to cooperate on space exploration. Then in September 1993, American Vice-President Al Gore, Jr., and Russian Prime Minister Viktor Chernomyrdin announced plans for a new space station. In November, plans for Freedom, Mir-2, and the European and Japanese modules were incorporated into a single International Space Station. Boeing began as NASA’s prime contractor for U.S. hardware in January 1995.

The ISS is composed of a number of modules, sharing primary power from large arrays of solar power cells. The first module, Zarya from Russia, was delivered to orbit by a Proton rocket on November 20, 1998. On December 4, the first Anmerican component, Unity, a connecting module, was carried up by Space Shuttle Endeavour on flight STS-88; it was then joined with Zarya to form an embrionic ISS. Unity was built by Boeing in MSFC facilities. Additional building supplies were carried to the ISS in May 1999, aboard STS-96.

The ISS continued to be assembled throughout the next decade, and has been continuously occupied since February 7, 2001. In March 2010, Boeing completed its contract and officially turned over to NASA the U.S. on-orbit segment of the ISS.

Shortly after NASA was formed, the Orbiting Solar Observatory was launched, and was followed by the Orbiting Astronomical Observatory (OAO) that carried out ultraviolet observations of stars between 1968 and 1972. These showed the value of space-based astronomy, and led to the planning of the Large Space Telescope (LST) that would be launched and maintained from the forthcoming space shuttle. Budget limitations almost killed the LST, but the astronomy community especially Lyman Spitzer and the National Science Foundation pressed for a major program in this area. Congress finally funded LST in 1978, with an intended launch date of 1983.

MSFC was given responsibility for the design, development, and construction of the telescope, while Goddard Space Flight Center (GFC) was to control the scientific instrument and the ground-control center. As the Project Scientist, MSFC brought on board C. Robert ODell, then chairman of the Astronomy Department at the University of Chicago. Several different people, at various times, served as the project manager. The telescope assembly was designed as a Cassegrain reflector with hyperbolic mirror polished to be diffraction limited; the primary mirror had a diameter of 2.4m (94in). The mirrors were developed by the optics firm, Perkin-Elmer. MSFC did not have a facility to check the end-to-end performance of the mirror assembly, so the telescope could not be totally checked until launched and placed in service.[29]

The LST was named the Hubble Space Telescope in 1983, the original launch date. There were many problems, delays, and cost increases in the program, and the Challenger disaster delayed the availability of the launch vehicle. Finally, on April 24, 1990, on Mission STS-31, Shuttle Discovery launched the Hubble telescope successfully into its planned orbit. Almost immediately it was realized that the optical performance was not as expected; analysis of the flawed images showed that the primary mirror had been ground to the wrong shape, resulting in spherical aberration.

Fortunately, the Hubble telescope had been designed to allow in-space maintenance, and in December 1993, mission STS-61 carried astronauts to the Hubble to make corrections and change some components. A second repair mission, STS-82, was made in February 1997, and a third, STS-103, in December 1999. For these repair missions, the astronauts practiced the work in MSFC’s Neutral Buoyancy Facility, simulating the weightless environment of space.

Through the 1990s, the Hubble did provide astronomy images that had never before been seen. During the next decade, two additional repair missions were made (March 2002 and in May 2009), eventually bringing the telescope to even better that its initially intended performance.

Even before HEAO-2 (the Einstein Observatory) was launched in 1978, MSFC began preliminary studies for a larger X-ray telescope. To support this effort, in 1976 an X-Ray Test Facility, the only one of its size, was constructed at Marshall for verification testing and calibration of X-ray mirrors, telescope systems, and instruments. With the success of HEAO-2, MSFC was given responsibility for the design, development, and construction of what was then known as the Advanced X-ray Astrophysics Facility (AXAF). The Smithsonian Astrophysical Observatory (SAO) partners with MSFC, providing the science and operational management.

Work on the AXAF continued through the 1980s. A major review was held in 1992, resulting in many changes; four of the twelve planned mirrors were eliminated, as were two of the six scientific instruments. The planned circular orbit was changed to an elliptical one, reaching one-third of the way to the Moon at its farthest point; this eliminated the possibility of improvement or repair using the Space Shuttle, but it placed the spacecraft above the Earth’s radiation belts for most of its orbit.

AXAF was renamed Chandra X-ray Observatory in 1998. It was launched July 23, 1999, by the Shuttle Columbia (STS-93). An Inertial Upper Stage booster adapted by MSFC was used to transport Chandra to its high orbit Weighing about 22,700kg (50,000lb), this was the heaviest payload ever launched by a Shuttle. Operationally managed by the SAO, Chandra has been returning excellent data since being activated. It initially had an expected life of five years, but this has now been extended to 15 years or longer.[30]

The Compton Gamma Ray Observatory (CGRO) is another of NASA’s Great Observatories; it was launched April 5, 1991, on Shuttle flight STS-37. At 37,000 pounds (17,000kg), it was the heaviest astrophysical payload ever flown at that time. CGRO was 14 years in development by NASA; TRW was the builder. Gamma radiation (rays) is the highest energy-level of electromagnetic radiation, having energies above 100 keV and thus frequencies above 10 exahertz (1019 Hz). This is produced by sub-atomic particle interactions, including those in certain astrophysical processes. The continuous flow of cosmic rays bombarding space objects, such as the Moon, generate this radiation Gamma rays also result in bursts from nuclear reactions. The CGRO was designed to image continuous radiation and to detect bursts.

MSFC was responsible for the Burst and Transient Source Experiment, (BATSE). This triggered on sudden changes in gamma count-rates lasting 0.1 to 100 s; it was also capable of detecting less impulsive sources by measuring their modulation using the Earth occultation technique. In nine years of operation, BATSE triggered about 8000 events, of which some 2700 were strong bursts that were analyzed to have come from distant galaxies.

Unlike the Hubble Space Telescope, the CGRO was not designed for on-orbit repair and refurbishment. Thus, after one of its gyroscopes failed, NASA decided that a controlled crash was preferable to letting the craft come down on its own at random. On June 4, 2000, it was intentionally de-orbited, with the debris that did not burn up falling harmlessly into the Pacific Ocean. At MSFC, Gerald J. Fishman is the principal investigator of a project to continue examination of data from BATSE and other gamma-ray projects. The 2011 Shaw Prize was shared by Fishman and Italian Enrico Costa for their gamma-ray research.

Shortly before activating its new Field Center in July 1960, NASA described the MSFC as the only self-contained organization in the nation that was capable of conducting the development of a space vehicle from the conception of the idea, through production of hardware, testing, and launching operations.

Initially, engineers from Huntsville traveled to Florida to conduct launch activities at the Cape Canaveral Air Force Station. The first NASA launch facility there (Launch Complex 39) was designed and operated by MSFC, then in on July 1, 1962, the overall site achieving equal status with other NASA centers and was named the Launch Operations Center, later renamed the Kennedy Space Center (KSC).

Another major NASA facility, the Manned Spacecraft Center (MSC) located near Houston, Texas, was officially opened in September 1963. Designated the primary center for U.S. space missions and systems involving astronauts, it coordinates and monitors crewed missions through the Mission Control Center. MSC was renamed the Lyndon B. Johnson Space Center (JSC) in February 1973. Through the years, there have been a number of turf battles between MSFC and MSC/JSC concerning mission responsibilities.

When the Marshall Space Flight Center began official operations in July 1960, Wernher von Braun was the Director and Eberhard Rees was his Deputy for Research and Development. The administrative activities in MSFC were led by persons with backgrounds in traditional U.S. Government functions, but all of the technical heads were individuals who had assisted von Braun in his success at ABMA. The initial technical activities and leaders at MSFC were as follows:[31]

With the exception of Koelle, all of the technical leaders had come to the United States under Operation Paperclip after working together at Peenemnde. Von Braun knew well the capabilities of these individuals and had great confidence in them. This confidence was shown to be appropriate; in the following decade of developing hardware and technical operations that established new levels of complexity, there was never a single failure of their designs during manned flight.

The initial projects at MSFC were primarily continuations of work initiated earlier at ABMA. Of immediate importance was the final preparation of a Redstone rocket that, under Project Mercury would lift a space capsule carrying the first American into space. Originally scheduled to take place in October 1960, this was postponed several time and on May 5, 1961, astronaut Alan Shepard made America’s first sub-orbital spaceflight. The delays led to a circumstance similar to that of the first satellite; on April 12, 1961, Soviet cosmonaut Yuri Gagarin had become the first person to orbit the Earth.

By 1965, MSFC had about 7,500 government employees. In addition, most of the prime contractors for launch vehicles and related major items (including North American Aviation, Chrysler, Boeing, Douglas Aircraft, Rocketdyne, and IBM) collectively had approximately a similar number of employees working in MSFC facilities.

Several support contracting firms were also involved in the programs; the largest of these was Brown Engineering Company (BECO, later Teledyne Brown Engineering), the first high-technology firm in Huntsville and by this time having some 3,500 employees. In the Saturn-Apollo activities, BECO/TBE provided about 20-million man-hours of support. Milton K. Cummings was the BECO president, Joseph C. Moquin the executive vice president, William A. Girdini led the engineering design and test work, and Raymond C. Watson, Jr., directed the research and advanced systems activities. Cummings Research Park, the second largest park of this type in the Nation, was named for Cummings in 1973.

On May 25, 1961, just 20 days after Shepard’s flight, President John F. Kennedy committed the Nation to “achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth”.[32] In what would be called the Apollo Program, the primary mission of MSFC was developing the heavy-lift rockets the Saturn family. This required the development and equalization of three new liquid-fueled rocket engines, the J-2, the F-1, and the H-1 (rocket engine); in addition, an existing engine, the RL10, was improved for use on Saturns. Leland F. Belew managed the Engine Development Office.[33] The F-1 engine was, and still is the most powerful single-nozzle liquid-fueled rocket engine ever used in service; each produced 1.5-million-pounds thrust. Originally started by the U.S. Air Force, responsibility for the development was taken over by ABMA in 1959, and the first test firings at MSFC were in December 1963.

The original vehicle, designated Saturn I, consisted of two propulsion stages and an instrument unit; it was first tested in flight on October 27, 1961. The first stage (S-I) had a cluster of eight H-1 engines, giving approximately 1.5-million-pounds thrust total. The four outboard engines were gimbaled to allow vehicle steering. The second stage (SIV) had six gimbaled LR10A-3 engines, producing a combined 90-thousand-pounds thrust. Ten Saturn Is were used in flight-testing of Apollo boilerplate units. Five of the test flights also carried important auxiliary scientific experiments.

The Saturn IB (alternatively known as the Uprated Saturn I) also had two propulsion stages and an instrument unit. The first stage (S-IB) also had eight H-1 engines with four gimballed, but the stage had eight fixed fins of equal size fitted to the sides to provide aerodynamic stability. The second stage (S-IVB) had a single J-2 engine that gave a more powerful 230-thousand-pounds thrust. The J-2 was gimbaled and could also be restarted during flight. The vehicle was first flight-tested on February 26, 1966. Fourteen Saturn 1Bs (or partial vehicles) were built, with five used in unmanned testing and five others used in manned missions, the last on July 15, 1975.

The Saturn V was the pinnacle of developments at MSFC. This was an expendable, man-rated heavy-lift vehicle that was the most vital element in the Apollo Program. Designed under the direction of Arthur Rudolph, the Saturn V holds the record as the largest and most powerful launch vehicle ever brought to operational status from a combined height, weight, and payload standpoint.

The Saturn V consisted of three propulsion stages and an instrument unit. The first stage (S-IC), had five F-1 engines, giving a combined total of 7.5-million-pounds thrust. These engines were arranged in a cross pattern, with the center engine fixed and the outer four gimballed. The second stage (S-II), had five J-2 engines with the same arrangement as the F-1s and giving a total of 1.0-million-pounds thrust. The third stage (S-IVB) had a single gimballed J-2 engine with 200-thousand-pounds thrust. As previously noted, the J-2 engine could be restarted in flight. The basic configuration for this heavy-lift vehicle was selected in early 1963, and the name Saturn V was applied at that time (configurations that might have led to Saturn II, III, and IV were discarded).

The Apollo Spacecraft was atop the launch vehicle, and was composed of the Lunar Module (LM) and the Command/Service Module (CSM) inside the Spacecraft Lunar Module Adapter, with the Launch Escape System at the very top. The Apollo Spacecraft and its components were developed by other NASA centers, but were flight-tested on Saturn I and IB vehicles from MSFC.

While the three propulsion stages were the “muscle” of the Saturn V, the Instrument Unit (IU) was the “brains.” The IU was on a 260-inch (6.6-m) diameter, 36-inch (91-cm) high, ring that was held between the third propulsion stage and the LM. It contained the basic guidance system components a stable platform, accelerometers, a digital computer, and control electronics as well as radar, telemetry, and other units. Basically the same IU configuration was used on the Saturn I and IB. With IBM as the prime contractor, the IU was the only full Saturn component manufactured in Huntsville.

The first Saturn V test flight was made on November 9, 1967. On July 16, 1969, as its crowning achievement in the Apollo space program, a Saturn V vehicle lifted the Apollo 11 spacecraft and three astronauts on their journey to the Moon. Other Apollo launches continued through December 6, 1972. The last Saturn V flight was on May 14, 1973, in the Skylab Program (described later). A total of 15 Saturn Vs were built; 13 functioned flawlessly, and the other two (intended as backup) remain unused.

Wernher von Braun believed that the personnel designing the space vehicles should have direct, hands-on participation in the building and testing of the hardware. For this, MSFC had facilities comparable with the best to be found in private industries. Included were precision machine shops, giant metal-forming and welding machines, and all types of inspection equipment. For every type of Saturn vehicle, one or more prototypes were fabricated in MSFC shops. Large, special-purpose computers were used in the checkout procedures.

Static test towers had been constructed at ABMA for the Redstone and Jupiter rockets. In 1961, the Jupiter stand was modified to test Saturn 1 and 1B stages. A number of other test stands followed, the largest being the Saturn V Dynamic Test Stand completed in 1964. At 475 feet (145m) in height, the entire Saturn V could be accommodated. Also completed in 1964, the S1C Static Test Stand was for live firing of the five F-1 engines of the first stage. Delivering a total of 7.5-million-pounds thrust, the tests produced earthquake-like rumbles throughout the Huntsville area and could be heard as far as 100 miles (160km) away.[34]

As the Saturn activities progressed, external facilities were needed. In 1961, The Michoud Rocket Factory near New Orleans, Louisiana, was selected as the Saturn production site. A 13,500 acres (55km2) isolated area in Hancock County, Mississippi was selected to conduct Saturn tests. Known as the Mississippi Test Facility (later renamed the John C. Stennis Space Center), this was primarily to test the vehicles built at the rocket factory.

On January 5, 1972, President Richard M. Nixon announced plans to develop the Space Shuttle, a reusable Space Transportation System (STS) for routine access to space. The Shuttle was composed of the Orbiter Vehicle (OV) containing the crew and payload, two Solid Rocket Boosters (SRBs), and the External Tank (ET) that carried liquid fuel for the OV’s main engines. MSFC was responsible for the SRBs, the OV’s three main engines, and the ET. The Center also received responsibility for Spacelab, a versatile laboratory that would be carried on some flights within the Shuttle’s cargo bay. Other assignments included the adaptation of the Inertial Upper Stage Booster, a two-stage rocket that would lift Shuttle payloads into higher orbits or interplanetary voyages.

The first test firing of an OV main engine was in 1975. Two years later, the first firing of a SRB took place and tests on the ET began at MSFC. The first Enterprise OV flight, attached to a Shuttle Carrier Aircraft (SCA an extensively modified Boeing 747), was in February 1977; this as followed by a free landings in August and October. In March 1978, the Enterprise OV was flown atop a SCA to MSFC. Mated to an ET, the partial Space Shuttle was hoisted onto the modified Saturn V Dynamic Test Stand where it was subjected to a full range of vibrations comparable to those in a launch. The second space shuttle, Columbia, was completed and placed at the KSC for checking and launch preparation. On April 12, 1981, the Columbia made the first orbital test flight.

From the start, MSFC has had strong research projects in science and engineering. Two of the early activities, Highwater and Pegasus, were performed on a non-interference basis while testing the Saturn I vehicle.

In Project Highwater, the dummy second stage was filled with 23,000 US gallons (87m3) of water as ballast, and, after burnout of the first stage, explosive charges released the water into the upper atmosphere. The project answered questions about the diffusion of liquid propellants in the event that a rocket was destroyed at high altitude. Highwater experiments were carried out in April and November,1962.

Under the Pegasus Satellite Program, the second stage was instrumented to study the frequency and penetration depth of micrometeoroids. Two large panels were folded into the empty stage and, when in orbit, unfolded to present 2,300-square-feet (210-m2) of instrumented surface. Three Pegasus satellites were launched during 1965, and stayed in orbit from 3 to 13 years.

The overall Apollo Program was the largest scientific and engineering research activity in history. The actual landing on the Moon led to investigations that could have only been conducted on location. There were six Apollo missions that landed on the Moon: Apollo 11, 12, 14, 15, 16, and 17. Apollo 13 had been intended as a landing, but only circled the Moon and returned to Earth after an oxygen tank ruptured and crippled power in the CSM.

Except for Apollo 11, all of the missions carried an Apollo Lunar Surface Experiments Package (ALSEP), composed of equipment for seven scientific experiments plus a central control station (they were controlled from the Earth) with a radioisotope thermoelectric generator (RTG). Scientists from MSFC were among the co-investigators.

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Space flight simulation game – Wikipedia

A space flight simulation game is a genre of flight simulator video games that lets players experience space flight to varying degrees of realism. Many games feature space combat, and some games feature commerce and trading in addition to combat.

Some games in the genre aim to recreate a realistic portrayal of space flight, involving the calculation of orbits within a more complete physics simulation than pseudo space flight simulators. Others focus on gameplay rather than simulating space flight in all its facets. The realism of the latter games is limited to what the game designer deems to be appropriate for the gameplay, instead of focusing on the realism of moving the spacecraft in space. Some “flight models” use a physics system based on Newtonian physics, but these are usually limited to maneuvering the craft in its direct environment, and do not take into consideration the orbital calculations that would make such a game a simulator. Many of the pseudo simulators feature faster than light travel.

Examples of true simulators which aim at piloting a space craft in a manner that conforms with the laws of nature include Orbiter, Kerbal Space Program and Microsoft Space Simulator. Examples of more fantastical video games that bend the rules of physics in favor of streamlining and entertainment, include Wing Commander, Star Wars: X-Wing and Freelancer.

The modern space flight game genre emerged at the point when home computers became sufficiently powerful to draw basic wireframe graphics in real-time.[1] The game Elite is widely considered to be the breakthrough game of the genre,[1][2][3] and as having successfully melded the “space trading” and flight sim genres.[4] Elite was highly influential upon later games of its type, although it did have some precursors. Games similar to Elite are sometimes called “Elite-clones”.[5][6][7][8]

Space flight games and simulators, at one time popular, had for much of the new millennium been considered a “dead” genre.[9][10][11][12][13] However, open-source and enthusiast communities managed to produce some working, modern titles (e.g. Orbiter Spaceflight Simulator); and 2011’s commercially released Kerbal Space Program was notably well-received, even by the aerospace community.[14] Some more recent games, most notably Star Citizen, Elite: Dangerous, and No Mans Sky, have brought new attention to the space trading and combat game subgenre.

Realistic space simulators seek to represent a vessel’s behaviour under the influence of the Laws of Physics. As such, the player normally concentrates on following checklists or planning tasks. Piloting is generally limited to dockings, landings or orbital maneuvers. The reward for the player is on mastering real or realistic spacecraft, celestial mechanics and astronautics.

Classical games with this approach include Space Shuttle: A Journey into Space (1982), Rendezvous: A Space Shuttle Simulation (1982),[4] The Halley Project (1985), Shuttle (1992) and Microsoft Space Simulator (1994).

If the definition is expanded to include decision making and planning, then Buzz Aldrin’s Race Into Space (1992) is also notable for historical accuracy and detail. On this game the player takes the role of Administrator of NASA or Head of the Soviet Space Program with the ultimate goal of being the first side to conduct a successful manned moon landing.

Most recently Orbiter and Space Shuttle Mission 2007 provide more elaborate simulations, with realistic 3D virtual cockpits and external views.

Kerbal Space Program[15] can be considered a space simulator, even though it portrays an imaginary universe with tweaked physics, masses and distances to enhance gameplay. Nevertheless, the physics and rocket design principles are much more realistic than in the space combat or trading subgenres.

The game Lunar Flight (2012) simulates flying around the lunar surface in a craft resembling the Apollo Lunar Module.

Most games in the space combat[16] genre feature futuristic scenarios involving space flight and extra planetary combat. Such games generally place the player into the controls of a small starfighter or smaller starship in a military force of similar and larger spaceships and don’t take into account the physics of space flight, usually often citing some technological advancement to explain the lack thereof. The prominent Wing Commander, X-Wing and Freespace series all use this approach. Exceptions include the first Independence War and the Star Trek: Bridge Commander series, which model craft at a larger scale and/or in a more strategic fashion. It should be noted that I-War also features Newtonian style physics for the behaviour of the space craft, but not orbital mechanics.

Space combat games tend to be mission-based, as opposed to the more open-ended nature of space trading and combat games.

The general formula for the space trading and combat game,[17][18][19][20] which has changed little since its genesis, is for the player to begin in a relatively small, outdated ship with little money or status and for the player to work his or her way up, gaining in status and power through trading, exploration, combat or a mix of different methods.[21][22][1] The ship the player controls is generally larger than that in pure space combat simulator. Notable examples of the genre include Elite, Wing Commander: Privateer, and Freelancer.

In some instances, plot plays only a limited role and only a loose narrative framework tends to be provided. In certain titles of the X series, for instance, players may ignore the plot for as long as they wish and are even given the option to disable the plot completely and instead play in sandbox mode.[21] Many games of this genre place a strong emphasis on factional conflict, leading to many small mission-driven subplots that unravel the tensions of the galaxy.

Games of this type often allow the player to choose among multiple roles to play and multiple paths to victory. This aspect of the genre is very popular, but some people have complained that, in some titles, the leeway given to the player too often is only superficial, and that, in reality, the roles offered to players are very similar, and open-ended play too frequently restricted by scripted sequences.[21] As an example, Freelancer has been criticised for being too rigid in its narrative structure,[22][23] being in one case compared negatively with Grand Theft Auto,[23] another series praised for its open-ended play.[24]

All space trading and combat games feature the core gameplay elements of directly controlling the flight of some sort of space vessel, generally armed, and of navigating from one area to another for a variety of reasons. As technology has improved it has been possible to implement a number of extensions to gameplay, such as dynamic economies and cooperative online play. Overall, however, the core gameplay mechanics of the genre have changed little over the years.

Some recent games, such as 2003’s EVE Online, have expanded the scope of the experience by including thousands of simultaneous online players in what is sometimes referred to as a “living universe”[21][25][26]a dream some have held since the genre’s early beginnings.[27] Star Citizen, a title currently in open, crowd-funded development by Chris Roberts and others involved in Freelancer and Wing Commander, aims to bridge the gap between the EVE-like living universe game and the fast action of other games in the genre.[28]

An additional sub-class of space trading games eliminate combat entirely, focusing instead entirely on trading and economic manipulation in order to achieve success.[citation needed]

Most modern space flight games on the personal computer allow a player to utilise a combination of the WASD keys of the keyboard and mouse as a means of controlling the game (games such as Microsoft’s Freelancer use this control system exclusively[23]). By far the most popular control system among genre enthusiasts, however, is the joystick.[12] Most fans prefer to use this input method whenever possible,[23] but expense and practicality mean that many are forced to use the keyboard and mouse combination (or gamepad if such is the case). The lack of uptake among the majority of modern gamers has also made joysticks a sort of an anachronism, though some new controller designs[12] and simplification of controls offer the promise that space sims may be playable in their full capacity on gaming consoles at some time in the future.[12] In fact, X3: Reunion, sometimes considered one of the more cumbersome and difficult series to master within the trading and combat genre,[29][30] was initially planned for the Xbox but later cancelled.[31] Another example of space simulators is an arcade space flight simulation action game called Star Conflict, where the players can fight in both PvE and PvP modes.

Realistic simulators feature spacecraft systems and instrument simulation, using a combination of extensive keyboard shortcuts and mouse clicks on virtual instrument panels. Most of the maneuvers and operations consist of setting certain systems into the desired configuration, or in setting autopilots. Real time hands on piloting can happen, depending on the simulated spacecraft. For example, it’s common to use a joystick analog control to land a space shuttle (or any other spaceplane) or the LEM (or similar landers). Dockings can be performed more precisely using the numerical keypad. Overall, the simulations have more complex control systems than game, with the limit being the physical reproduction of the actual simulated spacecraft (see SimPit ).

Early attempts at 3D space simulation date back as far as 1974’s Spasim, an online multi-player space simulator in which players attempt to destroy each other’s ships.

The earliest known space trader dates to 1974’s Star Trader, a game where the entire interface was text-only and included a star map with multiple ports buying and selling 6 commodities. It was written in BASIC.

Elite has made a lasting impression on developers, worldwide, extending even into different genres. In interviews, senior producers of CCP Games cited Elite as one of the inspirations for their acclaimed MMORPG, EVE Online.[3][33][34] rlfur Beck, CCP’s co-founder, credits Elite as the game that impacted him most on the Commodore 64.[3] Developers of Jumpgate Evolution, Battlecruiser 3000AD, Infinity: The Quest for Earth, Hard Truck: Apocalyptic Wars and Flatspace likewise all claim Elite as a source of inspiration.[2][35][36][37][38]

Elite was named one of the sixteen most influential games in history at Telespiele, a German technology and games trade show,[39] and is being exhibited at such places as the London Science Museum in the “Game On” exhibition organized and toured by the Barbican Art Gallery.[40] Elite was also named #12 on IGN’s 2000 “Top 25 PC Games of All Time” list,[41] the #3 most influential video game ever by the Times Online in 2007,[42] and “best game ever” for the BBC Micro by Beebug Magazine in 1984.[43] Elite’s sequel, Frontier: Elite II, was named #77 on PC Zone’s “101 Best PC Games Ever” list in 2007.[44] Similar praise has been bestowed elsewhere in the media from time to time.[45][46][47][48][49]

Elite is one of the most popularly requested games to be remade,[30] and some argue that it is still the best example of the genre to date, with more recent titlesincluding its sequelnot rising up to its level.[22][1] It has been credited as opening the door for future online persistent worlds, such as Second Life and World of Warcraft,[42] and as being the first truly open-ended game.[24][50] It is to this day one of the most ambitious games ever made, residing in only 22 kilobytes of memory and on a single floppy disk.[25] The latest incarnation of the franchise, titled Elite: Dangerous was released on the 16 of December 2014, following a successful Kickstarter campaign.

Though not as well known as Elite, Trade Wars is noteworthy as the first multiplayer space trader. A BBS door, Trade Wars was released in 1984[51] as an entirely different branch of the space trader tree, having been inspired by Hunt the Wumpus, the board game Risk, and the original space trader, Star Trader. As a pure space trader, Trade Wars lacked any space flight simulator elements, instead featuring abstract open world trading and combat set in an outer space populated by both human and NPC opponents.[citation needed] In 2009, it was named the #10 best PC game by PC World Magazine.[52]

Elite was not the first game to take flight game mechanics into outer space. Other notable earlier examples include Star Raiders (1979), Space Shuttle: A Journey into Space (1982), Rendezvous: A Space Shuttle Simulation (1982),[4] and Star Trek: Strategic Operations Simulator (1982),[53] which featured five different controls to learn, six different enemies, and 40 different simulation levels of play, making it one of the most elaborate vector games ever released.[54] Other early examples include Nasir Gebelli’s 1982 Apple II computer games Horizon V which featured an early radar mechanic and Zenith which allowed the player ship to rotate,[55][56] and Ginga Hyoryu Vifam, which allowed first-person open space exploration with a radar displaying the destination and player/enemy positions as well as an early physics engine where approaching a planet’s gravitational field pulls the player towards it.[57] Following Elite were games such as The Halley Project (1985), Echelon (1987) and Microsoft Space Simulator (1994). Star Luster, released for the NES console and arcades in 1985, featured a cockpit view, a radar displaying enemy and base locations, the ability to warp anywhere, and a date system keeping track of the current date.[58][59][60]

Some tabletop and board games, such as Traveller or Merchant of Venus, also feature themes of space combat and trade. Traveller influenced the development of Elite (the main character in Traveller is named “Jamison”; the main character in Elite is named “Jameson”) and Jumpgate Evolution.[2][61]

The Wing Commander (1990-2007) series from Origin Systems, Inc. was a marked departure from the standard formula up to that point, bringing space combat to a level approaching the Star Wars films. Set beginning in the year 2654, and characterized by designer Chris Roberts as “World War II in space,” it features a multinational cast of pilots from the “Terran Confederation” flying missions against the predatory, aggressive Kilrathi, a feline warrior race (heavily inspired by the Kzinti of Larry Niven’s Known Space universe).[citation needed] Wing Commander (1990) was a best seller and caused the development of competing space combat games, such as LucasArts’ X-Wing.[62] Wing Commander eventually became a media franchise consisting of space combat simulation video games, an animated television series, a feature film, a collectible card game, a series of novels, and action figures.

Game designer Chris Crawford said in an interview that Wing Commander “raised the bar for the whole industry,” as the game was five times more expensive to create than most of its contemporaries. Because the game was highly successful, other publishers had to match its production value in order to compete. This forced a large portion of the video game industry to become more conservative, as big-budget games need to be an assured hit for it to be profitable in any way. Crawford opined that Wing Commander in particular affected the marketing and economics of computer games and reestablished the “action game” as the most lucrative type of computer game.[63]

The seeming decline of the space flight simulators and games in the late 1990s also coincided with the rise of the RTS, FPS and RPG game genres, with such examples as Warcraft, Doom and Diablo.[12] The very things that made these games classics, such as their open-endedness, complex control systems and attention to detail, have been cited as reasons for their decline.[12][13] It was believed that no major new space sim series would be produced as long as the genre relied on complex control systems such as the keyboard and joystick.[12] There were outliers, however, such as the X (1999-2016)[12] and Eve Online video game series.

Crowdfunding has been a good source for space sims in recent years, however. In November 2012 Star Citizen set a new record, managing to raise more than $114 million as of May 2016,[64] and is still under development. Elite: Dangerous was also successfully crowdfunded on Kickstarter in November and December 2012. The game was completed and released in 2014, and expansions are being released in stages, or “seasons”. Born Ready Games also closed a successful Kickstarter campaign at the end of 2012, having raised nearly $180,000 to assist with the completion of Strike Suit Zero.[65] The game was completed and released in January 2013. Lastly, the non-linear roguelike-like space shooter Everspace garnered almost $250,000 dollars on Kickstarter, and is currently in Early Access.[66]

No Man’s Sky (2016) is another self-published, open-ended space sim (though this one was not crowdfunded). According to the developers, through procedural generation the game is able to produce more than 18 quintillion (18*10^15 or 18,000,000,000,000,000) planets for players to explore.[67] However, several critics found that the nature of the game can become repetitive and monotonous, with the survival gameplay elements being lackluster and tedious. As summarized by Jake Swearingen in New York, “You can procedurally generate 18.6 quintillion unique planets, but you cant procedurally generate 18.6 quintillion unique things to do.”[68] Further, there was considerable disappointment upon its release among players, as players did not feel it lived up to its perceived hype.[69] Players felt that promotional materials were misleading, and the game was not like what was promised during development.[69] In November 2016, the game’s developer released the Foundation Update, which added some of the missing features players had initially hoped for.[70] A second update featuring working multiplayer may be forthcoming.[71]

Star Citizen, Elite: Dangerous and No Man’s Sky are three ambitious games that many players hoped would fulfill the long-held dream of an open, persistent universe that they can explore, share, and fight each other in.[72] All three succeed and fail at fulfilling this promise in different ways. In a Polygon opinion article, Charlie Hall compared the three games, praising Elite: Dangerous for its look and feel, as well as its combat, but criticizing it for not allowing players to step outside of their ships. He praises Star Citizen’s combat module, Arena Commander, but says the persistent universe module is currently unfinished and unstable. He praises No Man’s Sky for the letting the player explore and walk on a planet’s surface while encountering alien life forms, but says it is least like the others, having poor combat and a smaller scope overall. (The game does not yet have working multiplayer, for instance.[71]) He concludes by writing that players disappointed with any one of the three should be satisfied to try all of them, since each fills its own niche and brings something new and unique to the table.[72]

PC Gamer writer Luke Winkie also compared Star Citizen to No Man’s Sky, describing Star Citizen as “the other super ambitious, controversial space sim on the horizon”, and indicating that fans of the genre, disappointed in No Man’s Sky were turning to the as-yet-unfinished Star Citizen, while sometimes expressing concerns should the latter fail to deliver.[73] Dan Whitehead of Eurogamer gave the initial release of Elite: Dangerous a score of 8/10 and considered it to be “probably the most immersive and compelling recreation of deep space ever seen in gaming”, while finding some of the gameplay repetitive.[74] Other sandbox space sims include the Evochron series (2005-2015), and the as-of-yet unfinished Infinity.[75]

On March 10, 2013, the space flight simulator Kerbal Space Program reached the top 5 best selling games after its release on Steam.[76]

The open source community has also been active, with projects such as FS2 Open and Vega Strike serving as platforms for non-professional efforts.[13] Unofficial remakes of Elite[citation needed] and Privateer[77] are being developed using the Vega Strike engine, and the latter has reached the stage where it is offered as a working title to the public. In 2013 a hobbyist space flight simulator project was realized under usage of the open source Pioneer software.[78]

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Space flight simulation game – Wikipedia

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Ethereum Crash 2018: Why ETH Can Easily Survive the Crypto Carnage

Making Sense of the Cryptocurrency Crash 2018
How eerie is it that exactly 10 days ago, I was sitting in the exact same spot around the exact same time and writing about the possibility of an Ethereum crash? 10 days later, it has occurred and here I am, reiterating my stance. There’s little that has changed in my Ethereum price forecast for 2018 and I can tell you why.

As of now, a cryptocurrency carnage of epic proportions is underway. There’s blood splattered everywhere. Red digits are flashing on computer screens, hearts are sinking,.

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Ethereum Crash 2018: Why ETH Can Easily Survive the Crypto Carnage

Crypto Crash 2018: Ripple and Ethereum Still Have Huge Potential

Crypto Crash 2018: A Correction or Something More Ominous?
The sky is falling in the cryptocurrency world, as the prices are in the grips of a painful sell-off. Given the parabolic nature of the rise, investors continue to grapple with the bubble theory.

In a matter of days, the entire basket of cryptocurrencies has shed half of its market capitalization. The carnage has been widespread, and none of the major cryptocurrencies have been spared.

Bearish articles are making the rounds, and cryptocurrencies such as Ripple (XRP) and.

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Ethereum Price Forecast: DApps Might Send ETH Price Soaring in 2018

Ethereum Price Forecast
Given the recent rollercoaster in Ethereum prices, it’s time to consider what makes ETH more valuable than the 1,400 other cryptocurrencies on the market. I call this theory “trickle-down cryptonomics”—others call it “fat protocol theory.”

What am I talking about?

To put it simply, Ethereum’s greatest strength is that it serves as a launching pad for other cryptos. Namely, cryptos that operate as part of decentralized applications (DApps).

DApps are identical to regular apps, except for one small difference—they.

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Ethereum Price Forecast: DApps Might Send ETH Price Soaring in 2018

Ripple Price Prediction: Big Business Ensures Higher XRP Prices in 2018

Ripple News Update
Cryptocurrencies passed through all stages of Dante’s Inferno this week, but that doesn’t mean investors are confined to hell in perpetuity. There is a way out, and its name is Big Business.

Or to put it in crypto terms, “enterprise use-cases of blockchain technology may expedite token adoption” by “leveraging the power of existing institutions.” (My god, this industry needs better language.)

What am I talking about?

Let me explain…

When the market crashes, investors believe that cryptocurrencies are failing. This is true in some cases and horribly untrue in others.
Ripple (XRP) Price Chart.

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Kraken Exchange Review: Facts to Know Before Buying Any Cryptocurrency

Kraken Exchange Review
Kraken is one of the most popular exchanges where users can buy and sell cryptocurrencies. It is arguably the largest Bitcoin exchange, based on liquidity. Kraken was also the first Bitcoin exchange to have its trading price and volume displayed in the “Bloomberg Terminal”.

Having established its reputation in the cryptocurrency world, Kraken is the first choice of many international cryptocurrency traders.

The following table is a Kraken exchange review with all the basic info you need.
Kraken.

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Litecoin Price Forecast: Bad News Is Scaring Jumpy Investors, But Worry Not

Daily Litecoin News Update
A dark cloud is once again hanging over crypto-land. After two days of recovery following the massive crash, cryptocurrencies are back in the red zone. But this cloud has a silver lining that investors must not miss.

Here are three major negative headlines that have sparked pessimism in the crypto-world in the past couple days.

First, South Korea continued the tradition by leading the charge against cryptocurrencies. To begin with, South Korea’s largest bank will no longer be supporting bank accounts linked with cryptocurrency exchanges.

Secondly, the largest Korean exchange, Korbit, says it will no longer be entertaining.

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Litecoin Price Forecast: Bad News Is Scaring Jumpy Investors, But Worry Not

Litecoin Price Prediction: Upcoming Litecoin Upgrade To Make it Even Cheaper Than Bitcoin

Daily Litecoin News Update
It’s a quiet day in the cryptocurrency world. The storm has settled and the sun is out. Investors are finally out of choppy waters and trading with more peace of mind. Top cryptos, including Litecoin are trading in the green. At this point another piece of good news may serve as the icing on the cake that Litecoin investors may have been longing to taste.

Litecoin founder Charlie Lee updates from the headquarters that Litecoin’s next upgrade is on its way. As promised, the developers will be cutting down transaction fees to further make LTC transactions cheaper for users.

Later, he also updates that Litecoin, like Bitcoin, would be integrating.

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Litecoin Price Prediction: Upcoming Litecoin Upgrade To Make it Even Cheaper Than Bitcoin

Ripple Price Forecast: Korbit, IMF & Other Causes of XRP Price Crash

Ripple News Update
At the end of last week, it looked like cryptocurrencies would outrun the storm of government regulations bearing down on them. But that analysis was all wrong—it’s now clear that we were sitting in the eye of the storm.

However, the momentary calm wasn’t so bad. It led to a short-lived rally in Ripple prices, which in turn revived some enthusiasm on Reddit and other discussion boards.

Then a barrage of bad news broke over the weekend. Not only did this snap the optimism, but it reminded us that governments are getting.

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Ripple Price Forecast: Korbit, IMF & Other Causes of XRP Price Crash

Ethereum Price Forecast: ETH Poised to Become Safe-Haven Asset in 2018

Ethereum News Update
From the outside, all digital assets look the same. A lot of volatility. A lot of upside potential. Not a lot of variety.

This two-dimensional view of cryptocurrencies is pretty common among newbie investors, but experienced hands know it’s not true. There’s a world of difference between Monero and XRP, or between NEM and Dash. Cryptos are not one and the same.

Investors learn these nuances over time. Another important lesson is about “safe-haven assets.”

According to conventional wisdom, Bitcoin is the safe-haven asset of.

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Ethereum Price Forecast: ETH Poised to Become Safe-Haven Asset in 2018

Stellar Lumens Applications: Businesses That Accept XLM Currency

What is Stellar Lumens
Stellar is an open source network with the same blockchain technology used by bitcoin. But unlike bitcoin, Stellar’s transactions settle in 2 to 5 seconds allowing users to quickly exchange government-backed currencies. Stellar’s native coins are officially called lumens, or xlm. The best way to answer ‘what is Stellar lumens’ is to compare it with Ripple. Stellar lumens (xlm) is to the layman what Ripple (xrp) is to banks and financial institutions.

The year 2017 saw big names like IBM and Deloitte becoming.

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