If you're a "Star Trek" fan, then that opening voiceover by William Shatner probably still gives you goose bumps: "To explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before."
Enthralling as that notion may be, to most people, it probably seems like a sci-fi writer's wishful thinking. While astronauts have ventured as far away as the Moon and, over the last few decades, have routinely orbited Earth, they've yet to venture to other planets in our solar system, let alone into the vast emptiness between our solar system and those of other stars. The immense distances involved — 36 million miles (57.9 million kilometers) to Mars, 21.1 trillion miles (39.9 trillion kilometers) to Proxima Centauri, the nearest star — make deep space travel seem beyond reach of even the most extreme human ingenuity. What would power spacecraft over such long distances? What would keep astronauts safe from the perils of radiation and the muscle-and-bone-wasting effects of microgravity? How would crews avoid running out of food and water? And once they arrived at their destinations, how would they even be able to send messages back to Earth? It all sounds impossible.
Or not. NASA researchers and other brains are hard at work contemplating the challenges of deep space travel and dreaming up technologies to meet those challenges. They've already come up with a number of ideas — solar sails to power spacecraft, super-precise, atomic-powered instruments for navigation, and laser relays for long-distance communication — that are in the early stages of development and may be ready for testing in the next few years, according to NASA. Additionally, in 2011, the Defense Advanced Research Projects Agency, the Pentagon's research and development arm, promised to invest up to $500,000 in seed money in technologies needed for interstellar travel, according to the Los Angeles Times.
Many potential breakthroughs are still on the drawing board, and while they still have a ways to go, the fact that these inspirations come from credible scientists and engineers gives us hope that someday they'll become a reality — and humans will roam the cosmos. Here are 10 of the most interesting technological notions.
10: Spacecraft Equipped With Giant Solar Sails
Conventional rockets can put astronauts into orbit, but try using one to travel the enormous distances between planets and stars and you're likely to run out of fuel. That's why scientists have been working to develop alternative methods of propulsion and energy sources for rockets.
One promising, albeit outlandish, idea is to equip starships with giant sails, which would capture solar energy and use it for propulsion. This would be possible because light is made up of tiny, extremely energetic particles called photons, which in some ways behave like atomic particles. When light strikes a mirrorlike surface, the photons are reflected straight back. In the process, they transmit their momentum to the surface, pushing it forward, explains the Planetary Society.
One huge advantage of a solar sail would be that, unlike a rocket engine, it would cause a spacecraft to continually, steadily accelerate, so that the craft eventually would reach an extremely high rate of speed. One drawback of solar sails is that in order to provide sufficient force to propel a spacecraft forward, a sail would have to be many times larger than that spacecraft. Such sails might actually have to be built in space.
9: Super-high-speed Optical Communication
We all chuckled at the notion that E.T. was having trouble phoning home, but for interplanetary explorers, maintaining communication with Earth could be a major challenge. "If you can't communicate with the ship, then you don't know what the results are of your mission," Andreas Tziolas, a former research fellow at NASA who now heads Project Icarus, a private-sector effort to develop interstellar technology, told the Atlantic.
For that reason, NASA is funding a project called the Laser Communications Relay Demonstration, which would use laser beams to transfer data between spacecraft and stations on Earth at 10 to 100 times the speeds currently available. If the method proves to be feasible, astronauts on Mars could transmit data back to Earth at speeds of 100 Mbps or more, which is at least several times faster than the broadband Internet connections that the most technologically advanced ordinary Joes have in their homes. Conceivably, it would be possible to transmit a photographic image from Mars to Earth in about five minutes, compared to the 90-minute wait that scientists operating robotic rovers on the Red Planet presently must endure, according to PopSci.
8: Atomic-powered Clocks for Navigation in Deep Space
If you're going to travel in deep space, the last thing you want is to get lost along the way, crash on some strange planet, and have your robotic assistant running around wearing out its voice synthesizer, continually shouting "Danger, Will Robinson!" To avoid such a scenario, you need a really good a navigation system with a super-precise clock; this clock will be used to calculate distances.
That's why NASA is planning in 2015 to launch a spacecraft containing the experimental Deep Space Atomic Clock, a miniaturized, ultra-precise mercury-ion atomic clock that's 100 times more stable than existing navigational clocks. All clocks are imprecise to some degree. But this one is accurate to within a billionth of a second over a 10-day period. This means astronauts can use it to measure frequencies, which are used to calculate distances, with much greater precision.
7: Robotic Advance Teams
Founding a colony on a distant planet might be a daunting task for astronauts. They'd have to land in unfamiliar, possibly rough terrain, and then immediately set about erecting dwellings and a landing/launching pad to facilitate follow-up missions — all while searching for water, air and building materials. That's why NASA engineers, in league with Canadian and European colleagues, are at work developing robotic advance teams that would land in advance of human explorers to scope out the available resources and lay the groundwork for a settlement. On Mars or another planet, for example, rovers equipped with bulldozer blades or plows could go to work clearing and smoothing a landing spot, while others might amass rocks and other materials and process them to make a concrete runway. (Remember that the Space Shuttle's landing facility required 250,000 cubic yards of concrete, far too much to ever be transported from Earth.) Other robots might roam the surface, drilling and testing soil samples to look for usable oxygen and/or water, according to NASA.
6: Substitutes for Gravity
Watching Apollo astronauts hit golf balls fantastic distances might make microgravity look like great fun, but the truth is that it's extremely hard on your body. In fact, scientists say that some of the biggest potential problems facing astronauts in deep space are the physiological changes caused by weightlessness. Astronauts' muscles have a tendency to atrophy from lack of resistance, and they lose bone as well; in addition, weightlessness causes a loss of blood volume, so they feel lightheaded when they stand up. Additionally, it alters the human sense of balance, so that when space travelers return, they'll feel as if Earth is spinning out of control beneath their feet.
On short-term trips, astronauts have been combating such debilitating changes by using specially designed exercise equipment and by taking medications to combat bone loss. On a longer trip, however, it might make more sense to equip a ship with some sort of rotational mechanism to simulate gravity inside. Alternatively, scientists have proposed installing circular exercise tracks inside spaceships, upon which astronauts would peddle bikes in circles to simulate gravity's effect on their muscles and bones.
5: Suspended Animation for Long Trips
One of the major problems with traveling vast distances in space is that trips could take a long, long time. In a lot of science fiction movies, such as "Alien" and "Planet of the Apes," scriptwriters get around this problem by depicting astronauts slumbering for long stretches in suspended animation, like hibernating animals. Unfortunately, slowing the human metabolism and keeping a person alive for lengthy periods in that state is easier imagined than done. Surface-induced deep hypothermia — in layman's terms, freezing — probably isn't a good option, for example, since ice crystals begin to form inside the cells, and then destroy them as they grow, according to Michio Kaku, author of "Physics of the Impossible."
But there may be other methods of maintaining a person in suspended animation without the ice. In 2006, for example, researchers at Massachusetts General Hospital in Boston slowed down the metabolism and cardiovascular systems of mice by administering small, controlled doses of hydrogen sulfide, the foul-smelling toxic gas produced by rotting eggs and sewage, and then were able to reverse the state of suspended animation afterward, according to Science Daily. In subsequent experiments, the researchers accomplished this feat even without a reduction in body temperature.
4: Force Fields to Block Hazardous Radiation
Force fields are a staple of science fiction, in which they're usually used to protect a spaceship or space station from attackers. In "Star Wars," for example, the Death Star on which Darth Vader did his heavy breathing was protected by such a shield. But in actual deep space travel, scientists are looking to force fields to solve another problem — how to protect astronauts' bodily cells from the continual radiation bombardment in space that might cause them to develop cancers and other health problems.
For the most part, dangerous radiation in space comes from electrically charged particles: high-speed electrons and protons put out by the Sun, and huge, positively charged atomic nuclei put out by distant supernovas. Hypothetically, if a spaceship were equipped with a powerful electrical field that had the same charge as the incoming radiation, it might be able to deflect that radiation. Unlike the force fields in movies, however, a practical force field might involve some visible objects. In one scheme developed by NASA scientists in the mid-2000s, spheres made of a thin, strong material and coated with a very thin layer of a conductor such as gold would be floated at low altitude over a base camp on another planet and then charged with electricity, according to NASA. Portable versions of the same device could be used on spaceships and rover vehicles.
3: Warp Drives
In "Star Trek," the Starship Enterprise travels enormous distances in weeks and months, even visiting other galaxies — a feat that would be impossible at the speeds that spacecraft currently travel. The Enterprise does this by using warp drive, in which the spacecraft basically takes shortcuts through holes caused by distortions of space-time. (This is a tricky concept to grasp; imagine space and time as a giant tablecloth, one that you can stretch, twist and poke pathways through.)
This might seem like a totally goofy, ridiculous idea, but physicists actually have been contemplating it since at least the 1920s. In 1994, theoretical physicist and Trekkie Miguel Alcubierre actually published a scientific paper showing that a warp drive could be created without contradicting Einsteinian physics, which would seem to dictate that faster-than-light travel is impossible. According to Alcubierre, it would be possible to get around this limitation if a spacecraft used energy to create a sort of bubble around it, which would cause space-time to expand behind it and contract in the direction that the spacecraft wanted to go. One drawback of this speculative technology is that it would require enormous amounts of energy.
2: Growing Food on Spaceships
Like everybody else, astronauts in deep space would need to eat, and finding room inside a spacecraft to bring along the vast quantities of supplies needed to sustain them on trips lasting multiple years would be a major headache. That's why NASA scientists are looking for ways for astronauts to grow their own food while en route to other planets, without using soil or large amounts of water.
Aeroponic crops would be grown from special seeds suspended in the air in plastic frames, instead of being planted and fertilized with chemicals. Research has shown that aeroponically grown plants actually absorb more minerals and vitamins than ones grown in the ground, making them potentially more nutritious, according to NASA. But man does not live by broccoli alone, so scientists will have to come up with a way to provide a good protein source as well. Perhaps another promising technology is test-tube meat, grown in strips from stem cells in a laboratory. A Dutch professor recently announced that he had grown small strips of muscle tissue from a pig's stem cells, which could eventually lead to artificial, cruelty-free artificial beef, pork, chicken or lamb.
1: Recycling Air and Water in Deep Space
Another thing that astronauts will need in space is supplies of both breathable air and drinkable water, and obviously they can't haul Earth behind them to provide a continuously refreshed supply. That's why NASA scientists are working to develop air recovery systems that will filter, extract and restore to a ship's internal atmosphere as much oxygen as possible. By 2014, researchers expect to have the ability to recover as much as 75 percent of the oxygen from the carbon dioxide that astronauts breathe out, and by 2019, they hope to achieve 100 percent recovery, according to Space.com.
Additionally, great strides are being made in water recycling in space. The International Space Station, for example, is now equipped with a special system that recycles both urine and waste water from washing. It rotates them in a special distillation unit that compensates for the absence of gravity and separates the actual water from waste materials, microorganisms and other contaminants, according to Water-Technology.net.