“For the first five minutes it was playing, I was just choked up,” says Weir. “I was like ‘Okay, just don’t start start hysterically crying in this theater while you are surrounded by Fox executives.’ It was just this really emotional moment for me.”
Weir has good reason to feel so strongly. The Martian is out today, and Weir is now a NASA darling, but until April of last year, he was anonymously (if happily), employed as an Android developer. Then both the book and film rights of The Martian sold in a single week. “I didn’t leave my day job until The Martian was making more money than my day job,” he says.
Weir always wanted to be a writer. “I just also like regular meals and not living under an overpass,” he laughs. He also really liked being a programmer, a job he did for 25 years. In The Martian, his technical and artistic interests finally came together.
The Martian is the story of Mark Watney (played by Matt Damon in the movie), an astronaut left behind on Mars by his crewmates when they mistakenly assume he is dead after he is impaled on an antenna during a fierce dust storm. Watney, handily, turns out to be an interplanetary MacGyver, who relies on his wits and problem-solving skills to survive for 550 days on the Red planet before eventually being rescued.
Weir wrote The Martian for a very particular audience: engineers like himself. He had been writing as a hobby for many years and built up an audience of about 3,000 readers for his blog. “At the time I was writing it, I had no idea it would have any mainstream appeal,” he says. “People like us, we like to see you show your work. We like science and math and everything to be very accurate.”
Weir, writing for this extremely picky audience, went to great lengths to ensure that the science and technology of the Martian was as accurate as possible. He even wrote his own software to track the orbits of every craft involved in his story on every day of the mission. “The little secret is that I really did enjoy doing that research,” says Weir, “I’m like ‘Ooh! I should find out exactly what the tensile strength of this material is’. That’s actually fun for me and writing, as you know, is hard. So any excuse to get away from that for a while.”
There was only one problem. Weir didn’t know anyone at NASA, or even within the aerospace industry, so he relied entirely on publicly available information to plan his imaginary Mars mission. As it turns out, he got it mostly right.
Dr. Jim Green is Planetary Science division director at NASA. His organization handles all of NASA’s Mars science missions. “Our public affairs official contacted me one noon hour and said could I talk to Ridley Scott at 2 o’clock that afternoon?” says Green. “And I said the Ridley Scott? It’s not one of those calls I get every day.”
Green answered hundreds of questions from Scott and his team on things like ion propulsion engines, Mars ascent vehicles, spacesuits and equipment, radioisotope thermoelectric generators, and designs for Mars Rover vehicles, which feature in the book and, in many cases, in future Mars missions.
He also organized tours for the set designers so they could walk through the HABs (human habitations) that NASA is currently building as test articles, look at space suits, and examine the exact replica of the International Space Station that NASA has created on the ground. “They then could incorporate the look and feel of real NASA hardware in the movie.” he says. They also had to re-create the look and feel of Mars. “I sent them images of the landing sites for both Ares 3 and 4 (the two fictional Mars missions in The Martian),” says Green.
I quizzed Green on the plausibility of the mission design and technology used in the Martian. “The concepts that are in the book actually connect well to NASA’s program in a whole variety of ways: communication, finding sites on Mars, where they would travel, their ability to travel and locations, the things they would do on Mars, leaving Mars, the Mars ascent vehicle, ” he says. For example, NASA is currently doing a variety of research on building a Mars ascent vehicle to bring back samples from its Mars 2020 Rover.
Weir admits that he did cheat in a couple of areas. The first is the dramatic dust storm that opens the book. The Martian atmosphere is extremely thin at around 1/200 the thickness of Earth’s atmosphere, so even winds of 90 MPH would barely be noticeable, much less knock over a Mars vehicle or its radio antenna. “A violent Martian sandstorm could barely knock over a piece of paper,” says Weir. “I knew that when I was writing it, but I made a deliberate concession because it’s a man versus nature story and I wanted nature to get the first punch in.”
Green suggests an alternative natural hazard that could have caused havoc: lightning. “We have looked at areas after these big dust storms and have seen lightning strikes on the ground,” he says. “So a lightning strike could have destroyed the antenna.”
Once stranded, Watney’s immediate challenges include ensuring that he has air and water. Watney relies on the oxygenator in his HAB to produce oxygen. “We are building one for the Mars 2020 mission, our very first one on Mars, ” says Green. “It’s the first to have the ability to suck in CO2 and the pop off the oxygen for use in breathing.” NASA’s real HABs would also be built to last longer than the 31 days cited in the book. Based on the available flight trajectories to Mars, astronauts would either have to go to the planet for 20 days and come back or stay for a year.
Watney extracts hydrogen from the hydrazine in rocket fuel in order to make water. But Mars has ice underneath its surface, and during warm weather liquid water may be available in some areas, so Green suggests a simpler solution. “Watney would have been much better to walk outside, throw a grenade to blow a hole in the land, and go over and pick up the ice chips. He is standing on an ancient ocean bed. But when the book was starting to be written, he (Weir) didn’t know that.” Less dramatically, NASA is currently working with the European Space Agency on a drill that goes five meters down. It will also test its own two meter drill in the upcoming Insight mission.
Hermes, the main spacecraft featured in The Martian, relies on ion propulsion engines. NASA already uses ion engines but they are currently orders of magnitude smaller than those required to power a craft the size of Hermes. “I have ion engines on a mission right now called Dawn in orbit around the largest asteroid called Ceres,” says Green. “For human exploration, ion engines are being developed in the Asteroid Retrieval Engine. The concept there is that ion engines have the ability to move tons of material back and forth in orbits between Earth and Mars.”
Another concession Weir admits making in the book is on radiation. “I said the HAB and rovers and EVA (extravehicular activity) suits and everything are all ‘radiation shielded’. The thing is there is no material that is that thin and flexible and that has that kind of radiation shielding.”
Green seems less perturbed by the radiation issue. “What’s now known is it’s not a showstopper,” he says. The dose of radiation to which astronauts would be exposed on the journey to and from Mars is enough to increase the probability of developing cancer “from less than 1% to maybe 3% in 20 years.” NASA is also working on various ways to shield astronauts from radiation on the Martian surface, where the planet itself already blocks half the radiation coming from space. It turns out that water could provide one form of protection. “So you would probably design your radiation environment such that you would get an alert and you would crawl into a water-surrounding environment,” says Green.
Green is optimistic that NASA will be ready for a manned mission like that described in The Martian by the late 2030s or early 2040s. “I personally believe that we are getting very close to having all the information that we would need for a scientific basis to be able to support humans on Mars,” he says. “We know enough about the atmosphere. We have got global circulation models. We can predict the weather. We can land in various spots. We can get water.”
A visit to NASA has been one of the highlights of Weir’s post-Martian career. “I went to NASA for a week. It was probably the best week of my life,” he says. Weir did a series of VIP tours. At Johnson Space Center in Houston he was asked what he would like to see. “And my immediate answer was the mission control center,” he says. “Other kids dream about being astronauts. I dream about being a flight controller.”
Not that he didn’t get to meet some astronauts. Weir’s tour of NASA’s International Space Station replica was led by veteran astronaut Stan Love, who offered Weir his email address. “I have definitely made use of that,” he laughs. “He’s really friendly and really personable. I have been asking him all kinds of questions about NASA operations, how ISS works, and he’s happy to answer.”
Part of the reason that Weir is so popular at NASA is that the success of his book has brought more attention to its real-life Mars missions and the information the agency releases about them. “What I am really proud about is how well he did by just leveraging what we are putting out on the Internet,” says Green. But then he adds another reason. “Classics in science fiction are really part of the fabric of our society. This is why art is so critical. It’s not all about science. It’s really about creativity. It’s really about vision.”