Why Not Mars?

Funny, brilliant and insightful piece:

But fifty years of progress in miniaturization and software changed the balance between robots and humans in space. Between 1960 and 2020, space probes improved by something like six orders of magnitude[6], while the technologies of long-duration spaceflight did not. Boiling the water out of urine still looks the same in 2023 as it did in 1960, or for that matter 1060. Today’s automated spacecraft are not only strictly more capable[7] than human astronauts, but cost about a hundred times less [8] to send (though it’s hard to be exact, since astronauts have not gone anywhere since 1972[9]).

The imbalance between human and robot is so overwhelming that, despite the presence of a $250 billion[10] International Space Station National Laboratory, every major discovery made in space this century has come from robotic spacecraft [11]. In 2023, we simply take it for granted that if a rocket goes up carrying passengers, it’s not going to get any work done.

As for that space station, the jewel of human spaceflight, it exists in a state of nearly perfect teological closure, its only purpose being to teach its creators how to build future spacecraft like it. The ISS crew spend most of their time fixing the machinery that keeps them alive, and when they have a free moment for science, they tend to study the effect of space on themselves. At 22 years old [12], the ISS is still as dependent on fresh meals and clean laundry sent from home as the most feckless grad student.

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If the head of NOAA Ocean Exploration (budget: $25 million) or the U.S. Antarctic Program ($350 million) held a press conference announcing a plan to fulfill human destiny, they’d be carrying their belongings home in a cardboard box before sundown. But our space agency is held to a lower standard.

All this would be fine if it was just talk. But NASA spent more on their Moon and Mars programs in 2022 than the total budget of the National Science Foundation. And in 2024, they plan to start launching pieces of a new space station, the Gateway, which by the laws of orbital bureaucracy will lock us in to decades of having to invent reasons to go visit the thing.

Somehow we’ve embarked on the biggest project in history even though it has no articulable purpose, offers no benefits, and will cost taxpayers more than a good-sized war. Even the builders of the Great Pyramid at Giza could at least explain what it was for. And yet this project has sailed through an otherwise gridlocked system with the effortlessness of a Pentagon budget. Presidents of both parties now make landing on Mars an official goal of US space policy. Even billionaires who made their fortune automating labor on Earth agree that Mars must be artisanally explored by hand.

The whole thing is getting weird.

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The chief technical obstacle to a Mars landing is not propulsion, but a lack of reliable closed-loop life support[48]. With our current capability, NASA would struggle to keep a crew alive for six months on the White House lawn, let alone for years in a Martian yurt.

The technology program required to close this gap would be remarkably circular, with no benefits outside the field of applied zero gravity zookeeping. The web of Rube Goldberg devices that recycles floating animal waste on the space station has already cost twice its weight in gold[49] and there is little appetite for it here on Earth, where plants do a better job for free.

I would compare keeping primates alive in spacecraft to trying to build a jet engine out of raisins. Both are colossal engineering problems, possibly the hardest ever attempted, but it does not follow that they are problems worth solving. In both cases, the difficulty flows from a very specific design constraint, and it’s worth revisiting that constraint one or ten times before starting to perform miracles of engineering.

What makes life support so vexing is that all the subcomponents interact with each other and with the crew. There’s no such thing as a life support unit test; you have to run the whole system in space under conditions that mimic the target mission. Reliability engineering for life support involves solving mysteries like why gunk formed on a certain washer on Day 732, then praying on the next run that your fix doesn’t break on Day 733. The process repeats until the first crew makes it home alive (figuratively speaking), at which point you declare the technology reliable and chill the champagne.

Unlike the medical research, there’s no way to predict how long these trials might take. A typical exploration profile[50] needs two different kinds of life support (for the spacecraft and the surface) that together have to work for about 1000 days. The spacecraft also has to demonstrate that it can go dormant for the time the crew is on Mars and still work when it wakes up.

Twenty years of tinkering with the much simpler systems on the space station have brought them no closer to reliability. And yet to get a crew to Mars, we’d need to get this stuff working like a Swiss watch. Humanity does not need a billion dollar shit dehydrator that can work for three years in zero gravity, but a Mars mission can’t leave Earth without it.