This article was first published in the November 2015 issue of WIRED magazine. Be the first to read WIRED's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.
There's something about the red planet -- so close and yet so far, inhospitable yet perhaps not totally uninhabitable -- that keeps us dreaming about getting there one day. Here's what that trajectory might look like, from the fictional world of best-seller The Martian (now a film starring Matt Damon) to the technology we still need to crack.
[h2]1. Andy Weir, Author of The Martian[/h3]
It opens on a nightmare: an astronaut is left on Mars and must survive on the hostile planet. The author of The Martian, Andy Weir, a former software engineer, includes so many technical details in his book -- orbital trajectories, the molecular tricks for turning air into water - that you might think a manned mission to Mars would be a cinch. Not so fast, Weir says. We shouldn't get hung up on humans reaching the surface.
WIRED: In the book, Mars missions have become almost routine. Do you think that we'll send astronauts to Mars anytime soon?
Weir: I suspect that the first manned exploration will actually be sophisticated robots on the surface and humans in orbit.
Why's that?
One of the challenges of unmanned exploration is the robots have to land themselves -- Mars is kind of a graveyard for probes. But imagine that they send seven probes into a parking orbit above the planet. Then they send humans. Now we have humans in orbit and in instant communication with the probes. The humans make sure that the probes land correctly.
Then is it even worth sending astronauts to the surface?
Oh yeah. Why did Sir Edmund Hillary climb Everest? [Laughs.] But it's hard to justify the additional costs and risk. Still, I would like to have humanity able to survive if there's a catastrophe on Earth. It's not within our technological reach to colonise Mars right now, despite what some groups say, but we can do it eventually.
Do you think science fiction can influence policy?
Things capture public attention, and if that's a side effect of my book, I'm happy. There's nothing Nasa is going to learn from me -- I'm just a space enthusiast. All I have to do is make shit up convincingly enough so you think it's true.
2. How can we get to Mars?
Just because all signs point to Mars's being a barren wasteland doesn't mean that people don't have plenty of ideas of how to get there. Here's an overview.
3. Look on the bright side
Life on Mars poses challenges. All you need is an open mind -- and to know you're not in Kansas anymore and will not see it again.
- **Pro:**If Earth is hit by a meteor or a deadly epidemic, people on Mars will probably be fine. Humanity will live to destroy yet another planet.
- **Con:**Light -- and radio waves -- can take from three to 22 minutes to travel from one planet to the other. That's one annoying Skype session.
- **Pro:**Future Martian athletes might grow taller and be able to jump higher with similar effort. Basketball will be fun.
- **Con:**If they have to play an NBA team on Earth, Martians are screwed --competing at full g will be like wearing cement shoes.
- **Pro:**A low-density atmosphere makes it easier to launch into orbit from the surface, which could facilitate resupply trips.
- **Con:**Far less protection from cosmic radiation, which could make those resupply trips likely to include a truckload of aluminium foil.
Earthlings have held much of the technology to become Martians for more than 30 years, according to Stephen Petranek, author of How We'll Live on Mars. It's the willpower and drive that are missing. Now that private efforts, such as Elon Musk's SpaceX, are providing some of that drive, here are the challenges they'll face.
- **Unlock water:**There is plenty of frozen water on Mars in the form of glaciers and polar caps. Plus, the soil is up to 60 per cent H<sub>2</sub>0. But we'll have to unlock it somehow. If that fails, University of Washington researchers have a plan B: a device called the Water Vapor Adsorption Reactor -- an industrial-level dehumidifier -- that could extract water from the atmosphere.
- **Make some air:**That water is going to be important, because we'll need it to make oxygen. (You probably remember this from school but just in case: stick two electrodes in a tank of water and turn on the power. Oxygen collects on the positive side and hydrogen on the negative.) When Nasa launches the heir to Curiosity in 2020, the agency will test a device that uses a similar process to split oxygen atoms off the CO<sub>2</sub> molecules in the Martian atmosphere.
- **Turn up the heat:**Terraforming! First, raise the temperature, perhaps with vast sunlight-reflecting mirrors. Frozen gases will be released, forming a denser atmosphere and causing a greenhouse effect. Water will flow. Plants will grow, releasing O<sub>2</sub>. If life once existed on Mars, maybe it can do so again.
Martha Lenio, mission commander of the HI-SEAS III Mars simulation programme, tells us what we're up against.
For a three-year mission with a spaceship, you have to figure out which spare parts you need, how to fix things when you're far away from Earth and how to deal with waste. I have no hesitation about having enough solar-powered batteries and hydrogen. I can see us recycling water and composting waste. I'm confident we can do missions where we come back to Earth or are resupplied, but I can't see a way for us to live sustainably on Mars. We haven't figured out how to live sustainably on Earth yet -- and Mars is very harsh. As told to Shara Tonn.
This article was originally published by WIRED UK
