Almost four hours ago the Mars Science Laboratory, including the car-sized Curiosity rover, successfully launched from Cape Canaveral and is now on its way to Mars. With the Russians still struggling to salvage the Phobos-Grunt mission, which has been trapped in Earth orbit for weeks now after its engines refused to fire, one can only hope that the hunger of the Great Galactic Ghoul has been sated for now and that MSL and Curiosity will make it to the Red Planet. If all goes according to plan, this time next year the largest Mars rover in history will be driving around Gale Crater and vaporizing rocks with its laser, because it's about damn time we sent out a rover with a laser. So it can blast annoying Martians and, through the wonders of spectroscopic examination, gain new awareness of their material composition. ("We are v-r-r-iends! Ouch!")
It's a welcome step forward for Mars research, particularly since there's now no longer any threat of the probe being cancelled because of economic factors. What I'm not looking forward to is the possibility that Curiosity will be more grist for the mill of the unmanned-boosters' peanut gallery. That is, the people who almost seem to be offended by the idea of human space exploration, or who think that calling spaceships "canned monkeys" is an endearing habit that totally makes people want to come over to their point of view.
The history of robotic Mars exploration has been incredible, all right. It's incredible that we've got as much out of robots as we have, and the ultimate cost of all their scientific insights would probably be incredible as well. There's one thing I'm curious about that, unfortunately, Curiosity won't be able to help me with; it's the question of whether all the science done by all the probes that have ever been landed on Mars over the last forty years could have been replicated by an astronaut actually on Mars in one week, or if it would be more like two weeks.
I'm not saying this to denigrate the people behind the actual Mars probes. Mars is a forbidding environment full of challenges alien to Earth, and it's hard enough to build a machine that works properly - let alone a machine that's rugged enough to keep on trucking in an environment that no human has any direct experience with. Yet, the limitations imposed upon past probes as a consequence of building them to endure the Martian environment had a definite effect on what they could actually do there. Remember Sojourner, the first successful Mars lander after the original Viking probes? It was a technical triumph - but that triumph wasn't free. Sojourner was not that much bigger than an Xbox 360, had a maximum speed of 0.036 kilometers per hour, and could operate as much as five hundred meters away from its lander. Over the eighty-three sols - that is, Martian solar days - it was in operation, Sojourner took five hundred and fifty photographs and analyzed sixteen locations.
It was a technical triumph, yes. But it also sounds like the sort of work that a lone astronaut, operating from a fixed base on Mars, could literally do in about an hour and get back to base in time for lunch. I expect that Curiosity will do good science, and will help pave the way for future human exploration, but it's inherently limited by the fact that it's a robotic rover at least partially dependent on a mission control which could be anywhere from three to twenty-two light-minutes away.
I'm not sure what the unmanneders - though there's got to be a better word for those people who support robotic missions and denigrate human ones - want me to take away from their arguments. What I usually end up taking from them is that they are willing to accept the return of a limited scientific payload in exchange for the expense of sending humans to do all this science themselves. Personally, though, I can't see myself coming around to that point of view - I can't yet accept the notion that, for a given amount of scientific returns, it would be cheaper to use robots than astronauts. Robots leave humans out of potentially dangerous situations, yes, but we pay through the nose for the privilege.
Nor do any of them, from my perspective at least, have the sort of psychological weight as the idea of boots on Mars.