Daily Archives: April 9, 2020

People began traveling in space in 1961 in tiny spacecraft called capsules, which were launched from Earth by powerful rockets. Russian crews still travel in this kind of craft, in Soyuz capsules, but Americans now travel into space in shuttles, which are rocket-powered space planes.

There is no oxygen in space, so all crewed spacecraft carry a life-support system. This supplies air for people to breathe. The system also includes equipment to keep the air at a comfortable temperature and pressure and to remove carbon dioxide and odors.

Gravity in space is much weaker than it is on Earth. When people travel in space, they seem to become weightless. This often makes them feel sick. Their bodies do not have to work as hard, because they are not fighting gravity to sit or stand up. If they stay in space for a long time, the lack of gravity makes their muscles start to waste away. Exercise and a special diet help to combat these effects.

Astronauts on the APOLLO PROJECT traveled to the Moon, about 239,000 miles (385,000 km) away. Russian cosmonaut Valeri Poliakov traveled a distance of about 174 million miles (280 million km) around Earth while in the Mir space station.

In the space race of the 1960s, the US Apollo Project beat the Soviet Union by landing the first astronauts on the Moon. The first Moon landing, by Apollo 11, took place on July 20, 1969, when Neil Armstrong and Buzz Aldrin became the first humans to set foot on another world.

The Apollo spacecraft was launched from Earth by the Saturn V rocket. On the launch pad, the whole assembly stood 365 ft (111 m) tall. The spacecraft itself weighed 50 tons (45 metric tons). It was made from three main modules (sections). The command module for flight control housed the three-person crew. The service module carried equipment, fuel, and a rocket motor. The lunar module detached from the craft and landed two astronauts on the Moons surface.

There were six Moon landings, beginning with Apollo 11 in July 1969 and ending with Apollo 17 in December 1972. During the missions, 12 astronauts explored the lunar surface for a total of over 80 hours and brought back nearly 880 lb (400 kg) of Moon rock and dust for examination on Earth.

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DK Space: Space Travel - Fact Monster

Paul M. Sutter is an astrophysicist at The Ohio State University, host of Ask a Spaceman and Space Radio, and author of "Your Place in the Universe." Sutter contributed this article to Space.com's Expert Voices: Op-Ed & Insights.

Interstellar space travel. Fantasy of every five-year-old kid within us. Staple of science fiction serials. Boldly going where nobody has gone before in a really fantastic way. As we grow ever more advanced with our rockets and space probes, the question arises: could we ever hope to colonize the stars? Or, barring that far-flung dream, can we at least send space probes to alien planets, letting them tell us what they see?

The truth is that interstellar travel and exploration is technically possible. There's no law of physics that outright forbids it. But that doesn't necessarily make it easy, and it certainly doesn't mean we'll achieve it in our lifetimes, let alone this century. Interstellar space travel is a real pain in the neck.

Related: Gallery: Visions of Interstellar Starship Travel

If you're sufficiently patient, then we've already achieved interstellar exploration status. We have several spacecraft on escape trajectories, meaning they're leaving the solar system and they are never coming back. NASA's Pioneer missions, the Voyager missions, and most recently New Horizons have all started their long outward journeys. The Voyagers especially are now considered outside the solar system, as defined as the region where the solar wind emanating from the sun gives way to general galactic background particles and dust.

So, great; we have interstellar space probes currently in operation. Except the problem is that they're going nowhere really fast. Each one of these intrepid interstellar explorers is traveling at tens of thousands of miles per hour, which sounds pretty fast. They're not headed in the direction of any particular star, because their missions were designed to explore planets inside the solar system. But if any of these spacecraft were headed to our nearest neighbor, Proxima Centauri, just barely 4 light-years away, they would reach it in about 80,000 years.

I don't know about you, but I don't think NASA budgets for those kinds of timelines. Also, by the time these probes reach anywhere halfway interesting, their nuclear batteries will be long dead, and just be useless hunks of metal hurtling through the void. Which is a sort of success, if you think about it: It's not like our ancestors were able to accomplish such feats as tossing random junk between the stars, but it's probably also not exactly what you imagined interstellar space travel to be like.

Related: Superfast Spacecraft Propulsion Concepts (Images)

To make interstellar spaceflight more reasonable, a probe has to go really fast. On the order of at least one-tenth the speed of light. At that speed, spacecraft could reach Proxima Centauri in a handful of decades, and send back pictures a few years later, well within a human lifetime. Is it really so unreasonable to ask that the same person who starts the mission gets to finish it?

Going these speeds requires a tremendous amount of energy. One option is to contain that energy onboard the spacecraft as fuel. But if that's the case, the extra fuel adds mass, which makes it even harder to propel it up to those speeds. There are designs and sketches for nuclear-powered spacecraft that try to accomplish just this, but unless we want to start building thousands upon thousands of nuclear bombs just to put inside a rocket, we need to come up with other ideas.

Perhaps one of the most promising ideas is to keep the energy source of the spacecraft fixed and somehow transport that energy to the spacecraft as it travels. One way to do this is with lasers. Radiation is good at transporting energy from one place to another, especially over the vast distances of space. The spacecraft can then capture this energy and propel itself forward.

This is the basic idea behind the Breakthrough Starshot project, which aims to design a spacecraft capable of reaching the nearest stars in a matter of decades. In the simplest outline of this project, a giant laser on the order of 100 gigawatts shoots at an Earth-orbiting spacecraft. That spacecraft has a large solar sail that is incredibly reflective. The laser bounces off of that sail, giving momentum to the spacecraft. The thing is, a 100-gigawatt laser only has the force of a heavy backpack. You didn't read that incorrectly. If we were to shoot this laser at the spacecraft for about 10 minutes, in order to reach one-tenth the speed of light, the spacecraft can weigh no more than a gram.

That's the mass of a paper clip.

Related: Breakthrough Starshot in Pictures: Laser-Sailing Nanocraft to Study Alien Planets

This is where the rubber meets the interstellar road when it comes to making spacecraft travel the required speeds. The laser itself, at 100 gigawatts, is more powerful than any laser we've ever designed by many orders of magnitude. To give you a sense of scale, 100 gigawatts is the entire capacity of every single nuclear power plant operating in the United States combined.

And the spacecraft, which has to have a mass no more than a paper clip, must include a camera, computer, power source, circuitry, a shell, an antenna for communicating back home and the entire lightsail itself.

That lightsail must be almost perfectly reflective. If it absorbs even a tiny fraction of that incoming laser radiation it will convert that energy to heat instead of momentum. At 100 gigawatts, that means straight-up melting, which is generally considered not good for spacecraft.

Once accelerated to one-tenth the speed of light, the real journey begins. For 40 years, this little spacecraft will have to withstand the trials and travails of interstellar space. It will be impacted by dust grains at that enormous velocity. And while the dust is very tiny, at those speeds motes can do incredible damage. Cosmic rays, which are high-energy particles emitted by everything from the sun to distant supernova, can mess with the delicate circuitry inside. The spacecraft will be bombarded by these cosmic rays non-stop as soon as the journey begins.

Is Breakthrough Starshot possible? In principle, yes. Like I said above, there's no law of physics that prevents any of this from becoming reality. But that doesn't make it easy or even probable or plausible or even feasible using our current levels of technology (or reasonable projections into the near future of our technology). Can we really make a spacecraft that small and light? Can we really make a laser that powerful? Can a mission like this actually survive the challenges of deep space?

The answer isn't yes or no. The real question is this: are we willing to spend enough money to find out if it's possible?

Learn more by listening to the episode "Is interstellar travel possible?" on the Ask A Spaceman podcast, available on iTunes and on the Web at http://www.askaspaceman.com. Thanks to @infirmus, Amber D., neo, and Alex V. for the questions that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following Paul @PaulMattSutter and facebook.com/PaulMattSutter.

Follow us on Twitter @Spacedotcom or Facebook.

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Is Interstellar Travel Really Possible? | Space

Mars as seen by the Hubble Telescope. NASA

Editors' note, December 19, 2015: This article was originally published August 6, 2015 and has been updated to include new developments in space travel efforts to Mars.

This year, scientists made one of the most important space discoveries in a long time, one that brings the mission of landing humans on the surface of another planet into laser focus -- and I'm not talking about Pluto's heart. They found compelling evidence that there is liquid water flowing on Mars, and that means there's the potential for life on the Red Planet.

You don't have to be a Space Camp alum like I am to feel your heart race at the very thought. Potentially finding water on Mars is an enormous triumph any way you look at it, and its discovery is sure to spur manned exploration of Mars' surface, something that's eluded us in the 46 years since landing on the moon.

Click here for more stories in CNET's Most Exciting Tech series

Outside of the scientific community's renewed interest in Martian exploration, there's another reason why I'm hopeful we'll set foot on Mars in my lifetime: we already have technology far more advanced than the spacecraft and control systems that got us to the moon, most of which ran on computers no more powerful than a calculator. These days, we also have the entrepreneurial hunger it takes to put people on the dusty red planet. A handful of smart people who share my passion for outer space have the drive and resources (ahem, money) to make it happen.

In my lifetime, human exploration of Earth's closest neighbor isn't just the province of space disaster movies like the Martian (thanks, Matt Damon), or abduction films like Mars Attacks and Mars Needs Moms. It's closer to reality than ever. Here are some of the important programs and people on our planet that will help put us on the Red Planet.

Like me, entrepreneur Elon Musk, the man behind SpaceX, the first private company to send supplies to the International Space Station (ISS), dreams of a Mars landing. Musk believes that humans could reach the planet in as few as 10 years.

Then there's billionaire Richard Branson, whose tourism venture, Virgin Galactic, is currently working on sending civilians (not just astronauts) into sub-orbital flight with a private spacecraft. Virgin Galactic isn't setting its sights on Mars just yet, but the company's work could one day help us get to the Red Planet.

Apollo 11 astronaut Buzz Aldrin is vocal about Mars too, advocating in his book " Mission to Mars" that it should be our next exploration goal. Meanwhile, Dutch non-profit foundation Mars One is planning and raising money for a one-way mission where some brave people establish a permanent base there, never to return to Earth. The Mars One group faces criticism from the scientific community, though, for not having a feasible plan to actually reach the planet with volunteers and sufficient supplies.

More credibly, NASA, the long-standing agency in charge of the US's space travel efforts, is optimistic about getting us to at least orbit Mars by President Obama's mid-2030 timeline, and has early-stage plans to make it real.

Though no one company or organization has an imminently viable action plan to get us to Mars just yet, these advancements and advocacy by the big players will hopefully pave the way for a mission to Mars.

Right now, the biggest challenges in getting to Mars are paying for the costly trip (the cheapest proposed plan would cost $76 million), keeping the astronauts healthy, and figuring out the right type of fuel for a round-trip voyage. Mars is an average 140 million miles from Earth (depending on its position in its orbit around the sun, and it would take a crew of astronauts around 200 days or 6 months to get there, at least. In order to cover that distance, we need sufficient fuel to power a spacecraft, and NASA is researching the best kind of ship and propulsion for such a trip.

SpaceX's Dragon Capsule.

SpaceX believes it has the right ship with the Dragon capsule, a manned spacecraft that could one day carry astronauts on interplanetary trips. Similarly, Texas-based rocket company Ad Astra Rocket is building the Vasmir electric engine that could possibly power a spaceship to Mars.

Meanwhile, SpaceWorks, an aerospace engineering firm out of Atlanta, has proposed the possibility of putting astronauts in torpor -- a hibernation-like state -- during the trip to conserve food and supplies and reduce the health risks associated with traveling in zero-gravity, like bone density loss. Though it sounds like something out of science fiction (in fact, astronauts were in a torpor state in the movies "Interstellar" and "2001: A Space Odyssey"), it could be a real, practical way to get humans to Mars as safely as possible.

The six-month trip to Mars won't be easy on the astronauts, as they face long stints of isolation, extended stays in cramped quarters and harsh weather conditions on the Martian surface. In order to keep them healthy, happy and safe, several organizations are currently conducting experiments that simulate conditions of being on Mars and traveling to the planet.

The NASA-funded Hawaii Space Exploration Analog and Simulation missions are studying a group of six humans living together in a confined, enclosed habitat, similar to what astronauts would live in on the surface of Mars during a mission. Meanwhile, astronauts from the European Space Agency (ESA) are in Antarctica at the Concordia research facility, a highly isolated compound that simulates what it's like to be on long space journeys in harsh conditions, hundreds of miles away from other humans.

The road to Mars through both private and government-funded space travel hasn't been easy so far. SpaceX's unmanned Falcon 9 rocket exploded just after launch in June 2015 during a resupply mission to the ISS. Likewise, Virgin Galactic's SpaceShipTwo crashed in the fall of 2014 during a test flight in California, killing one person.

NASA's Columbia Shuttle broke up during re-entry during the STS-107 mission in 2003. The launch is shown here.

These accidents stir up memories of the prominent tragedies NASA has endured over the last 50 years; Apollo 1 catching on fire on the launchpad during testing, the Challenger space shuttle exploding 73 seconds after launch and the Columbia space shuttle disintegrating during re-entry into the Earth's atmosphere. Each of those accidents claimed the lives of the crews on board.

The unfortunate truth is that in the quest for space travel, there will be near misses, failures and disasters. NASA carried on from its setbacks and so will SpaceX, Virgin Galactic and others, driven by the deep desire to explore uncharted territory.

Scientists, space agencies and private companies are still in the early stages of any kind of Mars mission, but their advancements in space travel are nothing short of astounding. Roughly 50 years ago, we were scrambling to send people on the week-long journey to the moon.

Now, we've sent astronauts to orbit the Earth for more than a year at a time, launched unmanned rovers to Mars to gather data about the planet's ability to host our species, and currently maintain a crew of people continuously living at the ISS (and posting pictures of the spectacular view to Twitter).

There are still untold hurdles to tackle before we can put a small crew of trained astronauts on the Red Planet, and many more after that until commercial rockets blast off for Mars with civilian spectators inside. But give it 50 more years, and I'm betting that we'll have a ship breaking away from Earth on a flight plan straight towards Mars. And when those first humans touch down, I'll be with the other fervent stargazers, watching every minute of it.

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Let's go to Mars! The future of space travel - CNET

"The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever," wrote Sovietspace travel pioneerKonstantin Tsiolkovsky in a letter in 1911. Scientists have long written and spoken about a perceived necessity to travel to other planets for the long-term survival of the human species.

While NASA, SpaceX, and other companies have relatively short-term plans to get us to Mars, what of the need to explore beyond our star, the Sun, which is estimated to die out in 7.5 billion years?

RELATED: DESTINATION MARS: 15 INCREDIBLE SPACEX MILESTONES, PAST AND FUTURE

Interstellar travel might not happen within our lifetimes, but space agencies and private companies are developing theories and methods to get to other stars. Here are 17 facts about how we might one day travel to other stars.

On his return from landing on the Moon, Neil Armstrong eloquently described the immense distance from our Moon to the Earth by saying,"it suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didnt feel like a giant. I felt very, very small."

The distance from the Earth to the Moon (383,400 km) is only a minuscule fraction of the distance to our Sun, and the distance from the Earth to the Sun (149.81 million km) is a proverbial drop in the ocean when compared with the distance to the closest star to the Sun.

The closest star to our Solar System is Proxima Centauri. It is part of a triple star system called Alpha Centauri and is about 4.24 light-years (or 1.3 parsecs) away from Earth. As NASA explains, that means that Proxima Centauri is40,208,000,000,000 (4 trillion) kmaway from Earth.

Our fastest current most reliable and fastest form of space travel is theion drive, which took theDeep Space 1mission to Comet Borrellyin 1998.Due to the immense distance from Earth to Proxima Centauri, using the ion drive to travel to our nearest neighboring star would take 18,000 years approximately2,700 human generations.

At our current rate of technological innovationsetting out on that trip would be futile as we would likely develop a technology that could catch up with, and overtake, the ion drive spacecraft years after it takes off from Earth.

In August of 2016 scientists documented a potentially habitable Earth-sized planet orbiting Proxima Centauri, which was subsequently dubbed Proxima b. Proxima b is an exoplanet, meaning the planet falls within theparameters of temperature required for life to develop.

Though this doesn't by any means mean we're going to find life on the planet its proximity to its sun also means its atmosphere might be exposed to deadly amounts of radiation the discovery did refresh hopes that we might one day travel to an alien planet orbiting a neighboring star.

Though Proxima Centauri is the closest star, besides the Sun, to Earth, its neighbor Alpha Centauri is much brighter and might also be a goal for missions of the distant future.

In his book Magnificent Desolation: The Long Journey Home from the Moon, Apollo 11 astronaut Buzz Aldrin wrote:

"I believe that space travel will one day become as common as airline travel is today. I'm convinced, however, that the true future of space travel does not lie with government agencies NASA is still obsessed with the idea that the primary purpose of the space program is science but real progress will come from private companies competing to provide the ultimate adventure ride, and NASA will receive the trickle-down benefits."

Elon Musk's private company, SpaceX, has already reignited the race to get to Mars and beyondwith its tried and tested reusable rocket boosters and plans for a historic a manned mission to the ISS with its reusable Crew Dragon capsule in May of this year.

It's not the only company that's looking to take great strides in space travel. Privately funded and volunteer initiatives includetheTau Zero Foundation, the ominously-namedProject IcarusandBreakthrough Starshot. All of these are aimed at achieving lift-off for interstellar travel.

Though the ultimate aim is to get humans to other planets and solar systems, one company, Breakthrough Starshot, thinks it can be the first to get an unmanned spacecraft to our nearest neighboring star, Proxima Centauri, using an intriguing method.

The $100 million initiative, which is privately funded byRussian billionaires Yuri and Julia Milner, aims to propel a tiny probe to the star by zapping its extremely lightweight sail using a powerful laser beam shot from Earth.

The company is relying on the miniaturization of future technologies, which would allow a spacecraft so light weighing less than a gram that it could be propelled by a laser's impact to eventually accelerate at around one-fifth of the speed of light. At this speed Breakthrough Starshot's spacecraft could reach Proxima Centauri in about 20 years.

In order for this to be achievable, Breakthrough Starshot needs technological advances that would allow a tiny spacecraft to carry thrusters, a power supply, navigation and communication equipment so it can beam back what it sees when it reaches Proxima b.

In July of last year, the Planetary Society launched and tested a Carl Sagan-inspired solar sailthat was successfully shown to be able to change its orbital trajectory using a light sail that converted the energy of photons from sunlight into propulsive energy.

Though the relatively easy and cheap manufacture of solar sails makes them a cost-effective method for space travel, they are unlikely to ever have the propulsive energy needed to carry humans. They also rely on light from stars, meaning that Breakthrough Starshot's laser-based alternative (in point 4) is the more viable option.

In order to gain the speed needed to travel long distances, they would also need time to accelerate. Right now, solar sails are viewed as a more viable method for transporting satellites within our Solar System, rather than humans to distant star systems.

The magnetic sail is a variation on the solar sail that is propelled by solar wind rather than by sunlight. The solar wind is a stream of charged particles that has its own magnetic field. As per New Scientist,a magnetic sail would surround a spacecraft with a magnetic field that repels the field of the solar wind, leading to magnetic propulsion of the spacecraft away from the Sun.

As with solar sails, the magnetic sail, unfortunately, has its limitations as a method for interstellar travel. As a magnetic sail-propelled spacecraft gets farther away from the Sun, the intensity of sunlight and of solar wind would drop dramatically, meaning that they would not be able to pick up the necessary speed to be propelled to another star.

The theory of special relativity states that particles of light, photons, travel through a vacuum at a constant speed of670,616,629 miles per hour. If we could somehow harness a craft that could travel near this speed, interstellar travel would be a completely different proposition to what it is today.

As NASA points out, throughout space there are, in fact, instances of particles, that aren't photons, being accelerated to near the speed of light. From black holes to our near-Earth environment, particles that are being accelerated to incredible speeds 99.9 percent the speed of light likely thanks to phenomena such as magnetic reconnection, might point to future research that could help us harness methods for reaching such speeds.

Many theories and hypothetical methods for interstellar travel near the speed of light have already been proposed several of these are mentioned in the points below.

Aside from predicting the existence of black holes, years before we ever saw one in an image, Einstein's theory of general relativity also allowed for the prediction of the existence of wormholes. This term, "wormhole", which describes tunnel-like shortcuts that traverse space and time, was coined byquantum physicistJohn Wheeler, who also coined the term black hole.

While wormholes are a tantalizing idea for space travel that has lit up the imagination of many a sci-fi enthusiast over the years, the likelihood that we could ever travel through one is incredibly slim. Firstly, we're not even certain wormholes exist; secondly, it is theorized that any type of matter that entered a wormhole would cause it to immediately close up.

Though it might be possible to stabilize the matter surrounding a wormhole and keep it open using a negative energy field called ghost radiation, all theories are very much in the hypothesis stage and most likely won't be tested in any true form for many years to come.

Wormholes are also problematic as the fact that they could transport matter across space would mean they are also a form of time machine, and would, therefore, be a violation of the laws of cause and effect. That hasn't stopped some scientists from devising theories and methods for methods of interstellar travel that utilize wormholes more on that in section 14.

NASA and other organizations are working on a proposed fuel-free engine that might just be impossible. Why? Because the payoff, if they were to succeed, would be so revolutionary it would completely change our capability for interstellar travel and would usher in a new era for humanity.

The 'helical' engine, dubbed the EmDrive, was first proposed byBritish scientist Roger Shawyer in 2001. Shawyer hypothesized that we could generate thrust by pumping microwaves into a conical chamber. In theory, the microwaves shouldbounce off the chamber walls exponentially. In doing so, they would create enough propulsion to power a spacecraft without fuel.

If that weren't enough, NASA engineer David Burns, who is part of laboratory tests on the theoretical engine, says that, given the EMDrive needs no fuel, a spacecraft powered by such a device could eventually reach a speed of 99.9 percent the speed of light.

While some researchersclaim to have generated thrustduringEmDrive experiments, the amount was so low that detractors claim the energy might have really been generated by external factors, such as Earth's seismic vibrations.

In a study titled Dark Matter as a Possible New Energy Source for Future Rocket Technology,scientists set out a method for a form of travel that would harness the energy of the universe's mysterious dark matter.

The researchers behind the paper proposed a variation on the EmDrive (see point 9) that would harness the energy of dark matter in order to fuel a rocket. The advantage? Much like the EmDrive it would be an engine that doesn't rely on chemical combustion, meaning it would remove the shackles from our current methods for interstellar travel.

The problem with dark matter rockets? We know next to nothing about dark matter, aside from the fact that it's there. This form of travel relies greatly on future discoveries. It is worth researching though, simply because dark matter is everywhere; if it could be used as a fuel, we'd have an endless supply.

Fusion rockets are a type of spacecraft that would rely on nuclear fusion reactions to take us to the far reaches of space. The possibility of developing such a rocket was explored in the 1970s bytheBritish Interplanetary Societyunderits Project Daedalus.

These rockets would rely on the vast amounts of energy released during nuclear fusion. The main method to have been put forth for releasing this energy in rockets is a method called inertial confinement fusion. This method would see high-powered lasers blast a small pellet of fuel to make its outer layers explode. In turn, this would crush the pellet's inner layers and trigger fusion.

Magnetic fields would then be used to direct the energy flow out of the back of the spacecraft in order to propel it forwards. Such a craft could travel the distance to Proxima Centauri in 50 years.The main problem with this method? In spite of decades of work, we are yet to see a working rocket fusion reactor.

By far the most reckless, and craziest, form of interstellar travel we've seen proposed is Nuclear pulse propulsion. This method would see a spacecraft propelled by the periodic throwing of a nuclear bomb out of the back of the craft before setting it off at just the right distance.

This method was seriously studied bytheUS governments military technology agency DARPA, under the code nameProject Orion. A spacecraft using nuclear pulse propulsion would need to be fitted witha giant shock absorber, that would allow for heavy radiation shielding that would protect the passengers.

Though such a spacecraft could theoreticallyreach speeds of up to 10percent of the speed of light, the concept was largely dropped after nuclear test bans came into force in the 1960s.

The Bussard ramjet is another solution for one of the limitations of relying on chemical combustion namely the weight of fuel. With our current best method for interstellar travel, the farther we want to get, the more fuel we need, the heavier the spacecraft, and the slower the acceleration.

The Bussard ramjet, proposed by physicist Robert Bussard in 1960, takes the concept of the fusion rocket (point 11) and gives it a twist; instead of carrying a supply of nuclear fuel, the spacecraft would ionize hydrogen from the surrounding space, and then suck it in using a largeelectromagnetic field scoop (as in the image).

The main problem with this as a method for interstellar travel is that, as levels of hydrogen are so sparse, the scoop might have to be hundreds of kilometers across.

TheAlcubierre drivewasfirst proposed in 1994by Miguel Alcubierre, a physicist at the University of Wales in Cardiff. The proposed drive would use "exotic matter," which are types of particles that have anegative massand exert a negative pressure. Rather importantly, "exotic matter" has not yet been discovered, meaning theAlcubierre Drive relies on a future discovery that might never happen.

The particles of "exotic matter" could distort space-time, making space ahead of the spacecraft contract and space behind it to expand. This would mean the craft was inside a "warp bubble" that could theoretically travel faster than light without breaking the laws of relativity.

The main problem? Aside from there being no evidence of "exotic matter" existing, the Alcubierre drive, which is basically a real-life warp drive from Star Trek, would need energy equal to the total energy of the universe to sustain it. Despite this, in 2012,NASA scientist Harold Sonny White and colleagues released a paper, titledWarp Field Mechanics 101, detailing work into the possibility of anAlcubierre drive.

For all of the theories of warp drives and EmDrives that could allow for travel at immense speed, the fact is that future astronauts will likely need to be prepared for incredibly long journeys. Even if we could travel at 99.9 percent of the speed of light, it would take us approximately 4 years to get to our nearest star system,Alpha Centauri.

As researcher andprofessor of experimental architecture Dr. Rachel Armstrong told the BBC, we need to start thinking about theecosystem that interstellar humanity will occupy out there in between the stars.

Were moving from an industrial view of reality to an ecological view of reality, Armstrong explained. "Its about the inhabitation of spaces, not just the design of an iconic object."

Rather than the hulking metallic spacecraft of films likeAlienand2001: A Space Odyssey,Armstrong envisions habitats with plenty of space for large biomes full of organic life that can sustain human beings on long interstellar journeys.

Taking yet another leaf out of sci-fi movies and novels, the idea of cryosleep has been seriously considered as a way to allow human beings to travel huge distances without aging and without having to be awake for trips that can last for months.

In 2016, NASA funded research into a type ofsuspended animationwhere entire crews are put into cryogenic sleep for the duration of long space missions. The firm behind this,SpaceWorks, is working on developing a method for putting astronauts into acontrolled state of advanced hypothermia that would allow them to hibernate during the long journeys through space.

From the outset of human existence weve looked up at the stars and projected our hopes and fears, anxieties and dreams there, researcher Dr. Rachel Armstrong toldthe BBC. Thanks to the great number of theories, theoretical models, and methods that are being devised today, Armstrong explains, interstellar travel"is no longer just a dream, this is an experiment now."

As Carl Sagan once wrote, "all civilizations become either spacefaring or extinct." That's why interstellar travel is important; whether we reach beyond our solar system a hundred or more than a thousand years from now, the fate of our future civilization ultimately depends on the development of interstellar travel technology that can take us distances that today seem unimaginable, and to places that we can only dream of.

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17 Facts About Interstellar Travel that Will Have You Dreaming of Space - Interesting Engineering