How to build a Mars colony that lasts – forever

发布时间:2017-05-05 04:01:07来源:未知点击:

By Victoria Jaggard in Washington DC (Image: Bryan Versteeg/Spacehabs.com) “Mars can’t just be a one-shot mission,” says Apollo 11 astronaut Edwin “Buzz” Aldrin, the second person to walk on the moon. He’s part of a group who met last week in Washington DC for the first Human to Mars Summit, or H2M. The astronauts, researchers and space flight firms aim to chart a path to the Red Planet by 2030. And they are thinking beyond mere visits. Though it won’t be easy, they say establishing a permanent, sustainable outpost on the Red Planet may be our civilisation’s only chance of long-term continuity. “Single-planet species don’t survive,” says former astronaut John Grunsfeld, who still works at NASA. “That’s a pretty sound theorem – just look at the dinosaurs. But we don’t want to prove it.” As the only other planet in the solar system we are likely to be able to settle on, Mars looks like the best first step towards establishing an off-Earth foothold. But making Mars a sustainable destination will require a few advances beyond those needed for one-off trips. For a start, humans who plan on seeding a colony will need bigger living quarters – both to accommodate life-support systems and supplies, and to minimise psychological trouble, said David Dinges at the University of Pennsylvania in Philadelphia. He recently reported on the behaviours of participants in the mock Mars 500 project, in which six men spent 520 days in a 3.6-by-20-metre habitat on Earth. Despite screenings, four had extensive problems with lethargy, insomnia and productivity, which Dinges attributes in part to their tight confinement. Just imagine how this would play out on much longer missions. But building larger habitats will require a rethink in transport, as landing heavy loads on Mars is a huge challenge. The International Space Station, which was built in stages during a series of launches, provides some inspiration. The parts for a Martian base could be delivered similarly, by landing modules in a series of missions. Then it could be built by a crew already on the surface, by robots in orbit or even by a crew based on a Martian moon. At H2M, Aldrin suggested sending three people to spend 18 months on Phobos, where they would remotely construct a base on Mars. Phobos has a nearly constant view of the Martian surface and is easier to land on than Mars because its lack of an atmosphere removes the need for technologies such as heavy heat shields and supersonic retro-rockets. Assuming a large enough base can be built, the next challenge will be a sustainable food supply. Growing vegetables is an option, but plants may need to deal with higher radiation, low air pressure and reduced gravity. If Mars gardeners are to use Martian soil, a knowledge of how crops respond to its contents, such as sulphates and perchlorates will be required. To get around any difficulties, genetically modified crops may come in useful, says Robert Ferl, director of the Interdisciplinary Center for Biotechnology Research at the University of Florida in Gainesville: “This is the era of understanding what happens to organisms at the genetic level.” We now know the patterns of gene expression behind how many plants on Earth assimilate key nutrients such as sulphates. This could eventually allow the right genes to be added to crops bound for Mars. Terrestrial plants growing in extreme places could also be adapted or mined for their hardier genes. For a less conventional meal, Anjan Contractor of Systems and Materials Research Corporation in Austin, Texas, has NASA funding to develop a 3D printer for hot food on deep-space missions. The food powders are UV sterilised, fortified with nutrients and have a shelf life of at least 15 years, says Contractor. His team has so far printed noodles, turkey loaf, basil paste, bread and cake – though they won’t taste their creations until a new, food-only printer is used for the job. There could be longer-term challenges to sustaining a colony, however. Richard Zurek, Mars chief scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, fears a colony will only sustain itself if it can find a resource to trade with Earth. “But that seems unlikely unless the cost of transport between planets is greatly reduced,” he says. Still, high public interest and the emergence of private space flight suggest that the dream of reaching Mars is closer to becoming reality, says Aldrin. “By implementing a step-by-step vision for Mars, we’ll plunge further outward into the solar system,” he says. More on these topics: