Don’t get me wrong, I am incredibly excited about any planetary mission, no matter how much it costs. However, there is something about the Mars Science Laboratory (MSL) that makes me uneasy. The project may be delayed (the MSL is scheduled for a 2011 launch) and it may be costing more than NASA projected, but it’s not these factors I’m worried about.
The MSL is built on a “bigger and better” mentality; it dwarfs both of the Mars Exploration Rovers Spirit and Opportunity, plus it is packing a rather impressive suite of 10 complex scientific instruments to carry out an unprecedented campaign in the Martian dirt. Oh, and did I mention it will be powered by radioisotope thermoelectric generators (RTGs), a complete departure from the tried and tested solar panelled rovers? Oh hold on, as the MSL weighs nearly a tonne, a brand new method of landing the thing is required (simply parachuting, air bag bouncing or rocket thruster powered landings are now passé). The “Skycrane” that looks like one of those hoverboards from Back to the Future II has been invented to gently lower the MSL (pictured above).
Still, I’m not too concerned, NASA has proven itself countless times at overcoming technological challenges. That’s why NASA is there, to research and develop new technologies and science. But what if the MSL has gone too far? What if the technology is too untried and untested? Unfortunately, it looks like the recent turn of events have taken even the MSL program manager by surprise…
RTGs have been used to power Mars landers before. Both 1976 landers Viking 1 and Viking 2 were powered by this handy power source. Now we have a rover that can operate in the night and day, at any latitude (which is a bonus, look at the trouble MER Spirit has been having recently). However, this will be the first rover to be powered by a radioactive source, the Viking landers were stationary. Also, when you have a rover as big as the MSL, novel ways of controlling the thing need to be devised. Unfortunately, at a very late stage in the project (late 2008), it was announced that the actuators (the motors and gears that allow the MSL to move) had faults and the engineers would need a few more months to work on the problem. This meant the MSL launch window was lost and we’ll have to wait until 2011 for the next one to open.
The actuator fault and postponed launch will cost NASA $400 million. Suddenly, the bizarre decision to axe the $2 million sample return cache from the MSL doesn’t seem so bad.
So why all this complexity? Why does the MSL need to be so advanced?
“We need a larger support structure. We need a more capable arm. We need to be able to look at not just the geology but much more the chemistry, much more the organic elements. We have to have a more capable rover,” said Jim Green, director of NASA’s planetary science division.
I understand that it is desirable to have an all-in-one rover that acts like (as the name suggests) a mobile laboratory, but is it necessary? The main purpose of the MSL is to seek out the potential for life (again), surely we can use tried and tested, less risky technological alternatives? After all, it looks like NASA has perfected the art of solar powered roving, is this really the best time to try something radically different?
Ex-NASA Associate Administrator Alan Stern agrees:
“It’s not just that it’s a bigger rover. It’s also an entirely new kind of landing system. It’s also that it’s nuclear-powered. It’s also that it’s carrying multiple instruments far beyond what’s ever been done. We need to go to a strategy where we can access Mars frequently and take advantage of what we’ve already invented.”
If the main priority is to search for life on Mars, why does there seem to be more attention on “trying something new” than using existing technology to carry out the same job? Sure, the MSL will do things faster, longer and with more precision, but it seems there are way too many expensive eggs in one flimsy basket. It even seems that MSL Project Manager Richard Cook has been taken by surprise by how many setbacks they have faced, saying, “…we didn’t extrapolate how much more complex it was” than the MER mission.
In my opinion, we are reaching the robotic limit on finding life on Mars (no matter how much methane the Mars atmosphere contains), and to have conclusive evidence we’ll need to go there ourselves. Alas, this isn’t going to happen for a while yet.