Saturday, October 25, 2008

Boondoggle to Mars

Why sending humans to Mars is a bad idea.

In an ironic continuation of its general war on science, the Bush administration proclaimed the goal of sending humans to Mars. A speech, a press release, and then nothing more was heard, doubtless because no one took the president seriously as a second coming of JFK, and also because the novelty of space adventure has, to some degree, worn off. Nothing more was heard, yet NASA has been squirrelling away on the plan anyhow, chopping budgets to real science missions in order to plan human missions to the Moon and Mars.

As a Star Trek fan and generally pro-science person who still draws inspiration from the Apollo Moon landings, I might be expected to support these goals. But the devil is truly in the details. The fact is that going to Mars turns out to be incredibly dangerous to the point of being essentially impossible, and thus also bound to be astronomically expensive even to attempt. And all this is to accomplish goals that we are already meeting via robotic exploration on Mars.

The dangers of sending humans to Mars are legion. First is the distance. The moon takes a few days to get to, but Mars takes over eight months. These are months the crew would have to exist in highly cramped conditions, taking care to not damage their tenuous vessel and losing bone and muscle strength all the time. After the same time coming back, humans would be in pretty rough shape on returning to Earth. The probability of accidents and catastrophe will mount to very high levels. More important is the fuel needed. The truly stupendous Saturn V was needed to loft the moon crafts, and far more will be needed just to get to Mars. Mars has 2.3 times the gravity of the Moon, so far more fuel would be needed both to arrest descent to, and to lift off from Mars. Mars has negligible atmosphere, especially oxygen, so huge amounts of supplies, including oxygen, would need to be brought along as well.

All these issues are probably surmountable. What may not be surmountable are radiation exposure issues. On earth we live in the cocoon of Earth's magnetosphere and under a heavy blanket of atmosphere, both of which protect us from intense cosmic and solar high-energy radiation. The Apollo astronauts, specially scheduled to avoid solar flares, were exposed to doses from 1X to 10X the yearly occupational allowed exposure (0.1 rads) in a matter of days. Extending that to the year plus involved in going to and existing on Mars yields exposures that are not only damaging, but possibly fatal (hundreds of rads). And shielding them with water, lead, or similar materials, is essentially impossible, due to obvious weight constraints.

To back up, one might ask.. what is the point of this exercise anyway? We are already mounting quite successful missions to Mars, thank you very much, with robots that have spent years trolling around the Martian landscape, sampling materials, snapping photos, and doing spectroscopic analysis. After a few more generations of rovers, it will be literally impossible to imagine anything they can't do that humans on the spot could.

Clearly scientific discovery and analysis is not the reason. What is the real reason? It is psychological- the adventure of it, to voyage far and wide, to spread our seed, plant our flag, and embody the archetype of the star-man, heavens-transcending, god-touching hero (e.g. Dave Bowman). The spiritual power of this adventure was greatest the first time at the climax of Apollo 11, and met with diminishing returns since then, petering out even by the end of the Apollo program. Turning back to Mars, a popular science fiction series paints our colonization of Mars in gritty but glowing terms, progressing from Red Mars to Green, and lastly to Blue. Adventure, derring-do, and spirituality were revolutionary reasons to go to the Moon, but less compelling reasons to go to Mars, now that we have seen the beauties and incredible harshness of all the planets, including Mars, up close.

Another reason may be the continuation of NASA's manned flight program. The excitement of space flight has been ebbing for years, coming to a sad end in the virtually pointless International Space Station, which might soon be held hostage by Russia- the only country with the wherewithal to get there. The station has no scientific rationale other than the study of the effects of space on humans- its other rationales of materials science, quirky biology, etc. are clearly not enough to interest any serious companies or academics, and thus the station has always been a solution in search of a question. The NASA manned program appears to spend more time inspiring elementary school students to do science and become astronauts than in actually doing serious or useful science. Recently, it has taken to hosting tourists on the space station. Its missions have become a circus of happy talk and kumbaya in space, at least when shuttles are not blowing up. The manned program is frankly a mess, and its only productive use has been to service the Hubble telescope, which, as another robot in space, has been a scientific as well as cultural gem.

The recent shuttle disasters were both ascribed in large part to a problematic culture at NASA, one which valued cheerleading over science, and public relations over truth. The manned program was always a PR program first and foremost, but has by this point become a inertial bureaucracy in symbiosis with its contractors that feeds on (and feeds) the public's faded romance with space dating from the Apollo program, without having a larger purpose, whether scientific, geostrategic, or even aesthetic.

We already go far beyond Earth by way of robots, which need no air, food, or other life support. And robots are critical to our future here on earth as well. Robotics and virtual reality are the technologies of the future, enabling us to learn, work, and play in remote locations, to telecommute, raise productivity, energy efficiency, and living standards. That is where money should be invested, and how we should be voyaging to phenomenally hazardous locations (or even across town). NASA should embrace this future of robotics and human extension with vigor, and not keep flogging past glories of top-gun derring-do.

The fact is that space is never going to be a good place for humans. Our fantasies of living on the moon and other planets, let alone colonizing them, are pure fiction. If we are already having problems living within our means on the Earth which is such a rich source of life-giving energy, food, and air, imagine how difficult it would be to live elsewhere with infinitely thinner means.

The Apollo program taught us one thing in the end, which is the Earth is unbelievably precious and life-giving. But it will not be for long if we continue to treat it as a way-station to the stars- as a home to be transcended and left behind rather than one to be nurtured and loved forever.

No comments:

Post a Comment