Manned Mars Mission Miscellanea

Maciej Cegłowski writes:

Unlike the Moon, which hangs in the sky like a lonely grandparent waiting for someone to visit, Mars leads a rich orbital life of its own and is not always around to entertain the itinerant astronaut. There is just one brief window every 26 months when travel between our two planets is feasible, and this constraint of orbital mechanics is so fundamental that we’ve known since Lindbergh crossed the Atlantic what a mission to Mars must look like. . . .

We shouldn’t send human beings to Mars, at least not anytime soon. Landing on Mars with existing technology would be a destructive, wasteful stunt whose only legacy would be to ruin the greatest natural history experiment in the Solar System. It would no more open a new era of spaceflight than a Phoenician sailor crossing the Atlantic in 500 B.C. would have opened up the New World. And it wouldn’t even be that much fun. . . .

It wasn’t always like this. There was a time when going to Mars made sense, back when astronauts were a cheap and lightweight alternative to costly machinery, and the main concern about finding life on Mars was whether all the trophy pelts could fit in the spacecraft. No one had been in space long enough to discover the degenerative effects of freefall, and it was widely accepted that not just exploration missions, but complicated instruments like space telescopes and weather satellites, were going to need a permanent crew.

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, 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. . . .

Mars is also not the planet we took it for. . . . The surface might be dry, but in most places there was water ice just underneath. Dynamic surface features hinted that water (or at least brine) was flowing to the surface from deep underground. . . . The news from the ground also got better. Arriving at Gale Crater in 2012, the Curiosity rover found itself looking at an ordinary lake bed, complete with organic sediment and odd stick-like structures that would be called fossils if we found them on Earth. The crater had been habitable for millions of years in the past, and something in it was still emitting methane at night. Over in its own crater, the Perseverance rover found complex organic molecules of indeterminate origin.

But the really exciting news for Mars was the discovery of unexpected life on Earth. . . . not just dozens of unsuspected microbial phyla, but two entire new branches of life . . . These new techniques confirmed that earth’s crust is inhabited to a depth of kilometers by a ‘deep biosphere’ of slow-living microbes nourished by geochemical processes and radioactive decay. . . . This underground ecology, which we have barely started to explore, might account for a third of the biomass on earth.

The fact that we failed to notice 99.999% of life on Earth until a few years ago is unsettling and has implications for Mars. The existence of a deep biosphere in particular narrows the habitability gap between our planets to the point where it probably doesn’t exist—there is likely at least one corner of Mars that an Earth organism could call home. . . . if our distant relatives are still alive in some deep Martian cave, then just about the worst way to go looking for them would be to land in a septic spacecraft.

But the fact that a Mars landing stopped making sense has not had the slightest impact on NASA’s plan to go there in a rocket-propelled terrarium.

And more:

The chief technical obstacle to a Mars landing is not propulsion, but a lack of reliable closed-loop life support. . . . 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 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. . . . The only way to explore Mars in our lifetime is to ditch the requirement that people accompany the machinery. . . .

In recent years, there’s been a remarkable division in space exploration. On one side of the divide are missions like Curiosity, James Webb, Gaia, or Euclid that are making new discoveries by the day. These projects have clearly defined goals and a formidable record of discovery.

On the other side, there is the International Space Station and the now twenty-year old effort to return Americans to the moon. These projects have no purpose other than perpetuating a human presence in space, and they eat through half the country’s space budget with nothing to show for it. Forget even Mars—we are further from landing on the Moon today than we were in 1965.

In going to Mars, we have a choice about which side of this ledger to be on.

This all makes sense. I’ve never thought much about this Mars mission thing because it’s always seemed like a bit of a joke. But if powerful people are really gonna try to use this as pretext to take a big chunk out of our national resources, then, yeah, it’s good to have people like Cegłowski pushing back.