Monthly Archives: May 2021

Is this how space travel will look some day? 'Sulu, punch it!' Shutterstock

Some climatologists argue it may be too late to reverse climate change, and its just a matter of time before the Earth becomes uninhabitable if hundreds of years from now. The recent movie Interstellar raised the notion that we may one day have to escape a dying planet. As astrophysicists and avid science fiction fans, we naturally find the prospect of interstellar colonization intriguing and exciting. But is it practical, or even possible? Or is there a better solution?

Science fiction has painted a certain picture of space travel in popular culture. Drawing on stories of exploration from an age of tall ships, with a good helping of anachronisms and fantastical science, space exploration is often depicted in a romantic style: a crew of human travelers in high-tech ships wandering the Galaxy, making discoveries and reporting back home. Perhaps they even find habitable words, some teeming with life (typically humans with different-colored skin), and they trade, colonize, conquer or are conquered. Pretty much, they do as humans have always done since the dawn of their time on Earth.

How close do these ideas resemble what we may be able to achieve in the next few hundred years? The laws of physics and the principles of engineering will go a long way to helping us answer this question.

Nature has given us a speed limit. We call it the speed of light about 186,000 miles per second because we first noticed this phenomenon by studying the properties of light, but it is a hard upper limit on all relative speeds. So, if it takes light one year to get somewhere, we cant possibly get there sooner than one year.

There is also the fact that the universe is big, really big. It takes light about eight minutes to get to our Sun, three years to get to the next-nearest star, 27,000 years to get to the center of our own Galaxy and more than 2,000,000 years to get to the next galaxy. The amazing thing about these distances is that, as far as the universe is concerned, this is all in the neighborhood.

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The vast distances between solar systems combined with the speed-of-light limit puts severe constraints on the realities of space travel. Every space-based science fiction writer has to decide early on how to deal with this white elephant standing proudly in the room. Much of the more recent science fiction employs some form of worm hole or warping space: bending the four-dimensional structure of space and time to create shortcuts between two spatial locations in the universe.

Such possibilities have been analyzed with some mathematical rigor, and although the studies are tantalizing, they show that these methods cannot work unless we discover a form of matter that behaves very differently than anything we have ever seen.

Practical space propulsion systems available today and for the foreseeable future are based on Newtons laws. In order to move forward, we have to throw something backwards or get hit by something moving forward. It turns out that even using the best propulsion systems available, there is not enough mass in the entire Universe to propel even a single human being up to half the speed of light. Even relative speeds of 0.01% of the speed of light start to get prohibitively expensive.

Things look slightly better with advanced propulsion concepts such as thermonuclear propulsion, but optimistic near-future designs still top out at a few percent of the speed of light.

Large distances combined with low speeds means that exploration is going to take time. Astrobiologists tell us that our galaxy has no shortage of habitable worlds: estimates range from at least 1 every 10,000 stars to as many as 1 every 10 stars. Even so, given the vast distances between stars and the low speeds achievable by realistic spacecraft, you should plan on voyages between worlds taking centuries to millennia.

Consider also what is meant by a habitable world. To an astrobiologist, this means a planet with water oceans orbiting a sun-like star. But habitability by humans requires more than just water, and the chances that ordinary humans could simply step out and populate such a world is slim. The atmosphere and living ecosystem of Earth is the result of its own unique evolutionary history, one that is unlikely to occur coincidentally on any other planet.

Despite its current problems, the Earth is still far closer to the ideal that our species grew up in than any world we are likely to discover out in the Galaxy. Climatologists warn us of the devastation that could result from increasing the carbon dioxide in our atmosphere by less than a tenth of a percent. Compared to that, another living world, with its own unique ecology, would most likely have an environment that is unbreathable and infertile at best, lethally toxic at worst.

Terraforming, or modifying such a world to be habitable to humans, would require reconstructing its atmosphere and biosphere practically from scratch, eradicating any native ecosystem. This would be a task orders of magnitude more challenging than the relatively minor tweaks needed to restore the Earths environment to a pristine state.

Perhaps a more fundamental question, then, is why humans would wish to colonize other worlds. Given the centuries-long treks between stars, interstellar voyagers would necessarily have moved beyond the need for a planet to support their lifestyle: their vessels would be their habitat, autonomous and self-sufficient. They would not have to seek out new homes, they would build them.

From an economic standpoint, this would be vastly more resource-efficient than converting entire planets. NASA-sponsored researchers have developed detailed plans for spinning habitats that could accommodate tens or hundreds of thousands of inhabitants, from material that could be mined on site from an asteroid a few hundred meters across. This type of construction would avoid one of the major expenses of space colonization: the cost of lifting millions of tons of building materials into space.

Since our Solar system contains millions of such asteroids, they could support a population many times that of Earth, in air-conditioned comfort, with a fraction of the effort and none of the exotic technologies envisioned to terraform Mars, for example.

Ultimately, travel to other stars and colonization of other planets will be driven not by need, but by desire: the intellectual impulse to explore strange new worlds, and perhaps an aesthetic preference for natural (albeit engineered) environments.

Where do we go now? The commercialization of space flight promises to bring the cost of space travel down considerably, from tens of thousands of dollars per kilogram to just hundreds of dollars per kilogram, through economies of scale and reusable rockets. This means that space will be more accessible to more and more people.

Already the lure of asteroid resources has fueled commercial competition. A single kilometer-sized metallic asteroid could supply hundreds of times the total known worldwide reserves of nickel, gold and other valuable metals. Space-based solar power could provide limitless renewable energy once the cost of construction in space becomes manageable.

The hyper-exponential growth that we have seen in other areas like automobiles and computers can now take place for space technology. The physical realities described above paint a very clear picture of the near future: orbital habitats perfectly designed for our lifestyle using resources obtained from our Sun, Earth, and the asteroids.

So if Earth ever become uninhabitable, we wont need to traverse the stars to find a new home. Orbital habitats will require a significant expansion of space industry, but this will happen soon enough, especially if we are forced to leave the planet for a little while so it can recover from our mistreatment.

Of course, if we discover warp drive, the picture will be entirely different.

This article is republished from The Conversation, a nonprofit news site dedicated to sharing ideas from academic experts.

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Fredrick Jenet is the creator/director of both the Center for Advanced Radio Astronomy at UT Brownsville and STARGATE, a public/private partnership with SpaceX. He works for UT Brownsville. He receives funding from the National Science Foundation (NSF), NASA, and the Department of Defense (DoD).

Teviet Creighton is a professor in the Center for Advanced Radio Astronomy at UT Brownsville and STARGATE, a public/private partnership with SpaceX. He works for UT Brownsville. He receives funding from the National Science Foundation (NSF), NASA, and the Department of Defense (DoD).

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If Earth falls, will interstellar space travel be our salvation? - Yahoo News

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Space is big. Really big. You just wont believe how vastly hugely mind-bogglingly big it is, writes Douglas Adams in the cult sci-fi novel, The Hitchhikers Guide to the Galaxy.

It might seem absurd, then, that space is also crowded at least, the region closest to Earth.

Why are we so intent on exploring space when we have so many problems right here on Earth? From resource management, to multispectral imaging, to radar mappers, our space-based tools can help us solve Earth-based problems. Soon, armadas of small satellites will connect the world by bringing the internet to everybody.

As we are realizing the benefits of our orbiting workforce, however, we must also be proactive in mitigating the rapid proliferation of space debris so we dont end up with a problem on the scale of air or ocean pollution before we even have the chance to inhabit the next frontier.

At present, more than 2,200 operational satellites are orbiting Earth. But the growing concern is the inoperative satellites, spent rockets and debris that also clutter the region collectively called space debris or space junk.

From the moment humanity entered space with the launch of Sputnik I in 1957, orbital debris began to accumulate. By 2020, those 2,200 operational satellites were joined by approximately 34,000 pieces of debris 10 cm in diameter or larger, roughly 900,000 objects from 1 cm to 10 cm, and more than 128,000,000 pieces under 1 cm. The mass of debris in Earth orbit totals nearly 7 million kilograms. While orbits eventually decay and debris can re-enter and burn up in Earths atmosphere, the process can take years.

Both satellites and space junk are primarily concentrated in two regions.

In Earths equatorial plane, just under 30,000 km above Earth surface, hundreds of satellites are in geostationary orbit. Most are communications and weather satellites,but they share their orbit with deceased predecessors.

The amount of junk in geostationary orbit pales in comparison to the satellites and debris in the zone that extends just above Earths atmosphere upwards to 2,000 km above its surface known as low-Earth orbit, or LEO. To get to higher orbits, the Moon, or other planets, spacecraft must pass through low-Earth orbit, where debris is most dense and orbital velocities are greatest. So, space junk imperils not merely spacecraft in LEO, but all forms of space travel.

As long as humans launch objects into orbit, space debris is inevitable.

Rocket launches leave boosters, fairings, interstages, and other debris in LEO. So do rocket explosions, which currently account for seven of the top 10 debris-creating events.

Human presence also creates orbital flotsam such as cameras, pliers, an astronauts glove, a wrench, a spatula, even a tool bag lost during space walks.

Some debris is created naturally from the impacts of micrometeoroids dust-sized fragments of asteroids and comets.

With limited lifetimes, operational satellites can become space debris. Satellites run out of maneuvering fuel, batteries wear out, solar panels degrade causing an orbital debris feedback loop, in which the problem is exacerbated when solar panels are sandblasted by micrometeoroids and tiny debris. As with rocket debris, spent satellites eventually re-enter Earths atmosphere and burn up, but the process can take years and the higher they orbit above Earth, the longer those orbits take to decay.

Space junk can impact operational spacecraft, yielding even more debris of all sizes, further increasing the impact risk. This is known as the Kessler syndrome, named for NASA scientist Donald J. Kessler, who hypothesized spacecraft and orbital debris could reach a density such that each impact generates more debris and a greater likelihood of colliding with other objects rendering the use of LEO impossible for decades. (This was depicted in the 2013 filmGravity, in which astronauts portrayed by George Clooney and Sandra Bullock are stranded in space after debris hits their shuttle.)

Even the tiniest space debris is a hazard: particles the size of dust grains, even paint chips, can scour hard-to-protect components like optics and solar panels, shortening operational lifetimes and creating even more tiny flecks of debris. An impact by a 1 kg object travelling at 7.0 km/s releases the same amount of energy as the detonation of 6 kg of TNT.

Now, LEO is about to become even more crowded. SpaceX, Amazons Project Kuiper, OneWeb Corporation and Canadas Telesat plan on placing constellations totaling upwards of 50,000 satellites in LEO. Meanwhile, near misses between spacecraft and extant space junk are already occurring with greater regularity. In September 2020, NASA fired the engines of theProgressresupply module docked with the International Space Station, to boost the stations altitude in order to avert a collision with a rocket fragment.

Also read: 2 Indians are trying to predict how junk flies in space, could help ISRO protect satellites

In the mid-1990s, NASA issued the first guidelines to mitigate the growing orbital debris hazard; other international agencies followed. In 2002, the Inter-Agency Space Debris Coordination Committee, comprised of 10 member nations, adopted a consensus set of guidelines for the coordination of activities related to the issues of man-made and natural debris in space. If the guidelines are followed, we can have a cleaner and more compliant environment in space for the future.

Aerospace corporations are now designing small satellites to address space junk proactively. Satellites are incorporatingelectric propulsion systemslike ion and Hall Effectthrustersas well asplasma thrustersto minimize small particles from chemical rockets, and as end-of-life de-orbit thrusters to push failing or inoperative spacecraft into Earths atmosphere.Researchers in Japan are even experimenting with wooden spacecraft to minimize the levels of toxic debris introduced into Earths upper atmosphere when spacecraft de-orbit.

But what about extant debris as well as the debris that the introduction of tens of thousands of new satellites will, inevitably, generate?

Some companies,are planning to leverage spacecraft to pick up space junk. Others are devising methods to capture orbital debris, includingnets,harpoonsandmagnets. Researchers at Tohoku University in Japan are devising a contactless de-orbiting solution, whereby a satellite fires a particle beam at debris, causing them to slow, lower their orbit and enter Earths atmosphere.

To keep space junk to a minimum and allow us to effectively utilize low-Earth orbit for future exploration we need concerted, collaborative efforts on multiple fronts to both eliminate existing space debris and prevent the generation of future debris.

While space debris present hazards, space debris mitigation presents an opportunity for clever entrepreneurs to solve both in the next frontier and, perhaps, right here at home.

Dr. Max Polyakov, Founder, Noosphere Ventures, Firefly Aerospace, EOS Data Analytics

This article was previously published in the World Economic Forum.

Also read: Space exploration is commercial now. Thats how it should be

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Not just Earth, humans are polluting space too. Heres how we can stop - ThePrint

Elon Musk and his company SpaceX recently announced their first all-civilian-crewed space flight. This will be the first mission to space where the passengers wont be NASA-trained astronauts. The crew for the Inspiration4 mission will be trained on site to be prepared to go to space.

SpaceX has launched two crewed flights to the International Space Station comprising U.S. and international astronauts. However, this Inspiration4 will be the first crew of civilians who arent trained astronauts.

The aims of Inspiration4 mission are noble: to promote a charity for the Saint Jude Childrens Hospital. The flight will be captained by Jared Issacman, a tech entrepreneur. He started an initial donation of $10,000,000 to promote the event. Then anyone who donated $10 had a chance to be picked for a position on the space crew.

The crew has now been selected, and the flight is set to launch in the fourth quarter of this year. The three other members including Issacman are Hayley Arceneaux, a physician assistant, Sian Proctor, a geoscientist, and Chris Sembroski, an aeronautical engineer.

Inspiration4 is a historic event for space exploration and for the human race. Space missions for the past hundred years have been the domain of federal governments and exclusive personnel. Now for the first time, a group of regular people like you and me, are going to be able to leave the planet.

This mission opens the door for potential future private enterprises into space. The upcoming economic implications of civilian space travel are promising. SpaceX already employs 10,000 people. The global space economy including satellite communication and technology makes 423.8 billion dollars a year. Similar private space companies are cropping up all over the country like Blue Origin and Virgin Orbit. This mission could inspire countless future scientists and engineers.

Private space ventures help the development of various sciences such as astronomy, geology, biology, etc. The basic research capable of being done outside of the atmosphere is immensely valuable. Private space allows space travel for research to be cheaper and more accessible. If there are more crews going into space, there is more potential for research to be done connected to these new missions. In the 2018 budget request, NASA showed broad support for private sectors of space travel.

Space exploration is the next crucial and necessary step for our species. Think of how the human race will change its priorities if a large portion of us could see the planet in context. This may seem like fluffy semantics, but it truly could change the paradigm attitude of our existence. Carl Sagan once said, There is perhaps no better a demonstration of the folly of human conceits than this distant image of our tiny world.

Perhaps this new mission will create a future where more of us can see that demonstration.

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OPINION: SpaceX is making history The Appalachian - The Appalachian Online

By Jonny Lupsha, Current Events WriterBeing unloaded from a US Air Force Douglas C-133B-DL Cargomaster, in Cape Canaveral, Florida, this first Atlas launch vehicle was intended to launch an unmanned Mercury spacecraft into orbit, but it exploded at launch. Photo by NASA / Wikimedia Commons / Public Domain

For the first time in its history, Smithsonians National Air and Space Museum in downtown Washington, D.C. will soon feature a full-size aircraft not based on real-life air or space travel. An X-wing, one of the fighter spaceships from George Lucass Star Wars universe, will be exhibited at the world-famous museum alongside historical artifacts like Neil Armstrongs Apollo 11 spacesuit.

The National Air and Space Museum makes for a crucial stop when visiting the nations capital. In his video series Experiencing America: A Smithsonian Tour through American History, Dr. Richard Kurin, the Smithsonians Under Secretary for History, Art, and Culture, said that exhibits include several capsules from NASAs Mercury missions.

Visitors to the Air and Space Museums sister site, the Steven F. UdvarHazy Center in Chantilly, Virginia, are bound to see a real capsule from NASAs Mercury missions. How did they come about?

President Dwight D. Eisenhower formed the National Aeronautics and Space Administration (NASA)as a civilian government agency on October 1, 1958, Dr. Kurin said. Its first mission, Project Mercury, was to put an American into orbit. NASA designed and built a small nose-cone capsule that would be launched into space atop a rocketthe challenge, aside from achieving a successful launch and orbit, would be to return the astronaut to Earth alive.

According to Dr. Kurin, NASA engineers came up with the idea of a conical spacecraft with a cylindrical nose. On the other end, a broad, flat base was covered by a fiberglass and resin heat shield. This would create a shock wave to slow down the spacecraft during re-entry.

NASA recruited astronauts from the military, especially test pilots, who helped work on the Mercury designs and make them more operator-friendly; and in 1961, Alan Shepard became the first American to enter space.

Downtown at the Air and Space Museum, another historic item from the Mercury missions is on display in the Boeing Milestones of Flight Hall: the space capsule Friendship 7.

On February 20, 1962, 41-year-old former jet fighter pilot John Glenn was propelled into space from Cape Canaveral, Florida, Dr. Kurin said. Glenns space capsule, the Friendship 7, was fabricated by McDonnell Aircraft Corporation. Its skin and structure were made of titanium, with nickel-steel alloy and beryllium shingles.

Dr. Kurin said it was a small aircraftjust 11 feet along and six feet across at its base. It was so small, in fact, that astronauts would joke that you dont get in the Friendship 7 so much as you put it on. Glenn orbited the Earth three times in approximately five hours, communicating by radio with NASAs Mercury Mission Control and taking pictures with two cameras and a rigged pistol grip that helped accommodate his bulky gloves. It splashed down safely in the Atlantic Ocean and Glenn was retrieved by the USS Noa.

Friendship 7 went on what became known as the fourth orbit, which is really a goodwill tour around the world, Dr. Kurin said. It arrived at the Smithsonian in November 1962 and was placed on display; in 1976, the space capsule was moved into the National Air and Space Museum, which opened up on the National Mall for the Bicentennial of the United States.

It was a testament to Americas spirit of discovery.

Edited by Angela Shoemaker, The Great Courses Daily

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Air and Space Museum in Spotlight as X-wing Exhibition Announced - The Great Courses Daily News

The report claims China wants to create destructive antisatellite weapons.Low-Orbit Security Threat

The US Director of National Intelligence released a report last month claiming Chinas upcoming space station poses a threat to national security.

China intends to launch a space station into low-Earth orbit in order to gain the military, economic, and prestige benefits that Washington has accrued from space leadership, according to the Annual Threat Assessment of the US Intelligence Communityreport released by the Office of the Director of National Intelligence.

The report said that its a part of Beijings bigger effort to compromise US security.

[The Peoples Liberation Army] will continue to integrate space services such as satellite reconnaissance and positioning, navigation, and timing (PNT) and satellite communications into its weapons and command-and-control systems to erode the US militarys information advantage, the report said.

The report also said that China is readying counterspace weapons to target US satellites.

Beijing continues to train its military space elements and field new destructive and nondestructive ground- and space-based antisatellite (ASAT) weapons, the report said.

That means theyre developing things such as spacecraft that can intercept and capture US satellites and/or Earth-based lasers that can disrupt them.

The report continued, China has already fielded ground-based ASAT missiles intended to destroy satellites in LEO and ground-based ASAT lasers probably intended to blind or damage sensitive space-based optical sensors on LEO satellites.

This is part of a growing call from experts for the US to prepare a space defense system. In fact, many claim that the USs current satellite infrastructure is very vulnerable to attacks from opposing nations.

Researchers at the Center for Strategic and International Studies released a report titled Defense Against the Dark Arts in Space: Protecting Space Systems from Counterspace Weapons in February. It details countermeasures the US can take to defend against antisatellite weapons.

As technologies surrounding space travel become more sophisticated, its only a matter of time before we figure out a way to weaponize them. It wouldnt be a bad idea then if we figured out a few defense systems while were at it.

READ MORE: Annual Threat Assessment of the US Intelligence Community [The Office of the Director of National Intelligence]

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US Intel Chief: Chinese Space Station is a Threat to National Security - Futurism