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Review: How We’ll Live on Mars

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How We’ll Live on Mars
by Stephen Petranek
TED Books, 2015
hardcover, 96 pp., illus.
ISBN 978-1-4767-8476-2

Most people who have spent even a little time exploring the Internet have probably run across a TED talk. These presentations, either at the main annual TED event or one of hundreds of “TEDx” spinoff events worldwide, are short talks—no more than 18 minutes—to discuss a project, topic, or provocative statement. Archived talks on the TED website range from “What happened when I open-sourced my brain cancer” to “How a driverless car sees the road.” And after each talk at a TED event there’s… another talk: no discussion, no Q&A with the audience, no reflection. Watch and learn.

Petranek believes that humans could be on Mars soon: the scenario he lays out in the book’s opening pages has the first human expedition landing on Mars in 2027.

The book version of a TED talk is How We’ll Live on Mars, by Stephen Petranek, published by TED Books, a Simon and Schuster imprint. The book is a companion to a TED talk he gave, although curiously that talk does not appear available on the TED website, despite claims to the contrary in the back of the book. (There is a blog post about his TED talk from earlier this year, but not the talk itself.) In any case, the book offers an argument nearly as brief as a TED talk—less than 100 pages—that humans will be living on Mars, and soon.

Petranek believes that humans could be on Mars soon: the scenario he lays out in the book’s opening pages has the first human expedition landing on Mars in 2027. That expedition, he believes, will not be carried out by NASA or other nations’ space agencies. Instead, he places his bet on the private sector, in particular SpaceX and its founder, Elon Musk. “In the same way we can draw a line from Wernher von Braun straight to Apollo 11,” he writes, “when a spaceship carrying astronauts lands on Mars in 2027, we may well be able to draw a line straight to Elon Musk—because that Mars lander will most likely have the SpaceX logo on it.”

Musk, of course, has made clear his ambitious of sending people to Mars within perhaps a decade, a case that Petranek accepts largely uncritically. Much of the book discusses, in limited detail, how people could live on Mars, and how the planet could even eventually be terraformed. Explaining how a SpaceX-led expedition will deal those issues requires some hand-waving on Petranek’s part, since Musk has offered few details about his Mars plans (he’s previously promised to offer more details later this year.)

Petranek does briefly mention some other private ventures, like Inspiration Mars and Mars One. He is understandably skeptical about Mars One’s prospects, citing the lack of funding they’ve raised and schedule slips. Yet, Mars One has at least outlined its plans in greater detail than SpaceX, for better or worse. Petranek takes SpaceX’s ability to carry out such missions largely on faith, with only limited hints from Musk about its “Mars Colonial Transporter” and other vehicles needed for such missions.

In the book, Petranek glosses over some of the challenges that Musk or anyone else will face landing humans on Mars. For example, talk to anyone at NASA working on Mars exploration and they’ll mention the challenges of entry, descent, and landing (EDL). The Martian atmosphere, they note, is just thick enough that spacecraft designers can’t ignore it, but not thick enough to be useful to help. The Curiosity rover, weighing approximately one ton, is about the largest spacecraft NASA engineers think they can land on Mars now, yet a human Mars lander would be dozens of times heavier.

Petranek, though, considers EDL a solved problem. “Changing the equation from large payloads like Curiosity to human cargo is mostly a step up in scale, frequency of cargo launches, and oxygen.” That assessment is no doubt a surprise to those working on projects like the Low-Density Supersonic Decelerator, a NASA project to test technologies for landing payloads heavier than Curiosity on Mars, one that has been only partially successful in two tests in the Earth’s stratosphere in the last year.

How “reasonably functional” must a Mars base be for people to flock there, and how much time and money will that take?

Those near-term struggles don’t mean the challenges of EDL, among other obstacles to sending humans to Mars, won’t eventually be solved. However, those challenges may take longer to overcome than optimists like Petranek argue. It might also require more resources than any single organization—company or agency—has as its disposal.

Then there’s the case of why humans will go to Mars. Petranek, like many other space advocates, argues for survival of the species, as well as to make a profit. “Once a Mars base is reasonably functional, people will flock there,” he claims. That, though, is largely an article of faith for space advocates. As bad as things get on Earth, it’s still far more hospitable than Mars, and a much easier place to make a buck. How “reasonably functional” must a Mars base be for people to flock there, and how much time and money will that take?

Answers to questions like that aren’t in How We’ll Live on Mars, a treatise that seems unlikely to sway many minds among those either convinced Mars is a part of our future or skeptical such missions can be done, especially by private ventures, in the coming decades. It is, then, very much like a TED talk: brief, glossy, and with no opportunity to ask questions it raises.