In The Martian we saw what kind of hacking was needed to stay alive for a relatively short while on Mars, but what if you were trying to live there permanently? Mars’ hostile environment would affect your house, your transportation, even how you communicate. So here’s a fun thought experiment about how you’d live on Mars as part of a larger community.
Not Your Normal House
Radiation on Mars comes from solar particle events (SPE) and galactic cosmic radiation (GCR). Mars One, the organization planning one-way trips to Mars talks about covering their habitats in several meters of regolith, a fancy word for the miscellaneous rocky material covering the bedrock. Five meters provides the same protection as the Earth’s atmosphere — around 1,000 g/cm2 of shielding. A paper from the NASA Langley Research Center says that the largest reduction comes from the top 15 to 20 cm of regolith. And so our Mars house will have an underlying structure but the radiation protection will come from somewhere between 20 cm to a few meters of regolith. Effectively, people will be living underground.
On Earth, producing water and air for your house is not something you think of doing, let alone disposing of exhaled CO2. But Mars houses will need systems for this and more.
It’s been 6 years since the hacker’s treat of a book, “The Martian” by Andy Weir, was self-published, and 2 years since the movie came out. We’ve talked about it briefly before, but enough time has passed that we can now write-up the book’s juicier hacks while being careful to not give away any plot spoilers. The book has more hacks than the movie so we’re using the book as the source.
For anyone unfamiliar with the story, Mark Watney is an astronaut who’s left for dead, by himself, on Mars. To survive, he has a habitat designed for six, called the Hab, two rovers, the Mars Descent Vehicle (MDV) they arrived in, and the bottom portion of the Mars Ascent Vehicle (MAV), the top portion of which was the rocket that his five crewmates departed in when they left him alone on the inhospitable desert planet. If you haven’t read it yet, it’s easy to finish over a long weekend. Do yourself a favor and pick it up after work today.
Watney’s major concern is food. They sent up some potatoes with the mission which will sprout roots from their eyes. To grow potatoes he needs water.
One component of the precious H2O molecule is of course the O, oxygen. The bottom portion of the MAV doesn’t produce oxygen, but it does collect CO2 from the Martian atmosphere and stores it in liquid form. It does this as one step in producing rocket fuel used later to blast off from the surface.
Is there room on Mars and Europa for cute robots? [NASA] — collaborating with [UC Berkley] and [Distant Focus Corporation] — have the answer: PUFFER, a robot inspired by origami.
PUFFER — which stands for Pop-Up Flat-Folding Explorer Robot — is able to sense objects and adjust its profile accordingly by ‘folding’ itself into a smaller size to fit itself into nooks and crannies. It was designed so multiple PUFFERs could reside inside a larger craft and then be deployed to scout otherwise inaccessible terrain. Caves, lava tubes and shaded rock overhangs that could shelter organic material are prime candidates for exploration. The groups of PUFFERs will send the collected info back to the mother ship to be relayed to mother Earth.
One of the biggest challenges of traveling to Mars is that it’s far away. That might seem obvious, but that comes with its own set of problems when compared to traveling to something relatively close like the Moon. The core issue is weight, and this becomes a big deal when you have to feed several astronauts for months or years. If food could be grown on Mars, however, this would make the trip easier to make. This is exactly the problem that [Clinton] is working on with his Martian terrarium, or “marsarium”.
The first task was to obtain some soil that would be a good analog of Martian soil. Obtaining the real thing was out of the question, as was getting similar dirt from Hawaii. [Clinton] decided to make his own by mixing various compounds from the hardware store in the appropriate amounts. From there he turned to creating the enclosure and filling it with the appropriate atmosphere. Various gas canisters controlled by gas solenoid valves mixed up the analog to Martian atmosphere: 96% dioxide, 2% argon, and 2% nitrogen. The entire experiment was controlled by an Intel Edison with custom circuits for all of the sensors and regulating equipment. Check out the appropriately dramatic video of the process after the break.
While the fern that [Clinton] planted did survive the 30-day experiment in the marsarium, it wasn’t doing too well. There’s an apparent lack of nitrogen in Martian soil which is crucial for plants to survive. Normally this is accomplished when another life form “fixes” nitrogen to the soil, but Mars probably doesn’t have any of that. Future experiments would need something that could do this for the other plants, but [Clinton] notes that he’ll need a larger marsarium for that. And, if you’re not interested in plants or Mars, there are some other interesting ramifications of nitrogen-fixing as well.
Interplanetary probes were a constant in the tech news bulletins of the 1960s and 1970s. The Space Race was at its height, and alongside their manned flights the two superpowers sent unmanned missions throughout the Solar System. By the 1980s and early 1990s the Space Race had cooled down, the bean counters moved in, and aside from the spectacular images of the planets periodically arriving from the Voyager series of craft there were scant pickings for the deep space enthusiast.
The launch in late 1996 of the Mars Pathfinder mission with its Sojourner rover then was exciting news indeed. Before Spirit, the exceptionally long-lived Opportunity, and the relatively huge Curiosity rover (get a sense of scale from our recent tour of JPL), the little Sojourner operated on the surface of the planet for 85 days, and proved the technology for the rovers that followed.
In these days of constant online information we’d see every nuance of the operation as it happened, but those of us watching with interest in 1997 missed one of the mission’s dramas. Pathfinder’s lander suffered what is being written up today as the first bug on Mars. When the lander collected Martian weather data, its computer would crash.
Like many other spacecraft, the lander’s computer system ran the real-time OS VxWorks. Of the threads running on the craft, the weather thread was a low priority, while the more important task of servicing its information bus was a high priority one. The weather task would hog the resources, causing the operating system equivalent of an unholy row in our Martian outpost. A priority inversion bug, and one that had been spotted before launch but assigned a low priority.
You can’t walk up to a computer on another planet and swap out a few disks, so the Pathfinder team had to investigate the problem on their Earthbound replica of the lander. The fix involved executing some C code on an interpreter prompt on the spacecraft itself, something that would give most engineers an extremely anxious moment.
[Tony Stark Elon Musk] envisions us sending one million people to Mars in your lifetime. Put aside the huge number or challenges in that goal — we’re going to need a lot of places to live. That’s a much harder problem than colonization where mature trees were already standing, begging to become planks in your one-room hut. Nope, we need to build with what’s already up there, and preferably in a way that prepares structures before their inhabitants arrive. NASA is on it, and by on it, we mean they need you to figure it out as part of their 3D Printed Hab Challenge.
The challenge started with a concept phase last year, awarding $25k to the winning team for a plan to use Martian ice as a building material for igloo-like habs that also filter out radiation. The top 30 entries were pretty interesting so check them out. But now we’re getting down to the nitty-gritty. How would any of these ideas actually be implemented? If you can figure that out, you can score $2M.
Official rules won’t be out until Friday, but we’d love to hear some outrageous theories on how to do this in the comments below. The whole thing reminds us of one of the [Brian Herbert]/[Kevin J. Anderson] Dune prequels where swarms of robot colonists crash-land on planets throughout the universe and immediately start pooping out building materials. Is a robot vanguard the true key to planet colonization, and how soon do you think we can make that happen? We’re still waiting for robot swarms to clean up our oceans. But hey, surely we can do both concurrently.
In summary, Watney survives by creating one glorious, but realistic, hack after another. NASA and the other astronauts support him by coming up with some marvelous hacks along the way. One, encompassing the entire spaceship containing the surviving astronauts, is developed by the ship’s Captain, Melissa Lewis. Okay, that one may not be totally realistic but it’s mind blowing.
Reading about the hacks is one thing. Seeing them on the screen adds another dimension. Matt Damon, as Watney, mixing his own waste with water to fertilize potatoes is an image you cannot create in your mind’s eye.
One usual trick Hollywood plays is to switch the actions of minor characters to the major characters. That leaves out the ‘little guy’ in the backroom who frequently has the great idea. Often that’s us. Here they kept the woman who first saw Watney moving equipment on Mars and the astrophysicist who, well, I won’t spoil it, saved the day.
It’s a wondrous trend to see science fiction movies based on real science and not being dumbed down to the point of insult. You know it has to be good if XKCD did a comic. Surprisingly, Hollywood didn’t do a ‘hack’ job on either of these movies.