"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."
Modular base
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.
Phobos first
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.
Printed noodles
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
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