The Martian’s Andy Weir talks to Ars about the science of Musk’s Mars vision
If Elon Musk has his way, humans will be going to the red planet—and soon. Over the past few days, our senior space-master Eric Berger has analyzed Musk’s Interplanetary Transport System plans in detail, and our chief scientist Dr. John Timmer has examined the science of how to generate resources on Mars. But Musk’s thoughts for getting to and living on Mars—both the nitty-gritty details and also the glossed-over blank bits—still come across to many folks as science fiction. It’s all well and good to talk about building an enormous rocket and a self-sustaining Martian colony, but it’s another thing entirely to do it.
So who better to discuss the differences between science and science fiction than an actual science fiction author—one who studied up for years on the problems of surviving on Mars before crafting a cracking good story about how exactly it might work? And as it happens, we know the perfect such person: author Andy Weir, whose best-selling novel The Martian (and the subsequent Ridley Scott movie) covers much of the same ground Musk wants to cover—though Musk is dreaming on a much larger scale.
“In-situ resource generation”
Though Musk and SpaceX envision a long-term plan that involves thousands of launches to Mars, the company wants to bring most of those spacecraft back to Earth—otherwise, as Musk explained, we’d end up with a gigantic “spacecraft graveyard” littering Mars. This leaves us with two options: the Martian spacecraft have to bring their return fuel with them, or they have to generate it somehow on Mars (“in situ,” as the terminology goes). Since every gram of mass going to Mars must be paid for in fuel (including the mass of the fuel itself), generating the fuel on Mars is highly preferable to hauling all that fuel with you and paying the mass penalty for it.