Mars rover Curiosity has landed. You know this because you have an Internet connection and because the hair-raising landing--though conducted in the middle of the night on a Sunday/Monday--was a huge media spectacle, and justifiably so. NASA just delivered the most sophisticated suite of science instruments ever packaged on a planetary rover onto the surface of Mars via an untested landing maneuver, instruments that should provide us with two uninterrupted years of unrivaled geological science on another planet. That in itself is a truly incredible story. But it’s not the whole story.
Every interplanetary robotic mission has had its technological “firsts,” and each has had its impact on the design of the missions that would follow. We’ve gone from small rovers to larger ones, from very human-dependent robots to ones that possess degrees of autonomy. It’s impossible to at this early stage to even begin to understand what Curiosity’s science legacy will be, but from a technological standpoint its legacy is already taking shape--to see it, you simply have to read between this week’s headlines. There are a few things we can extrapolate from Curiosity’s successful landing that will have huge impacts on robotic space exploration going forward.
We can put big things in places we couldn't before
“I think this is an example of how the ambitions of the robotic exploration community keep expanding,” Dr. Robert Gold, Chief Technologist of the Space Department at Johns Hopkins Advanced Physics Lab, says of the MSL mission. “We started with the Sojourner rover [part of the Mars Pathfinder mission] that was about the size of my briefcase. Then we had Spirit and Opportunity, which were about the size of a desk. Now we’ve got Curiosity--about the size of a small car.”
This uptick in size is no accident, and it wasn’t easy to engineer. With each successive Mars rover and lander mission, spaceflight engineers kept coming up with new ways to get larger objects and more science instruments onto the Martian surface because the solution that worked for the previous mission generally wouldn’t scale up for the newer, larger payload. With the sky crane that deposited Curiosity at the bottom of Gale Crater, the problem of scalability seems to have been at least temporarily solved.
“We wanted to build a capability to get a metric ton to the surface of mars,” Michael Meyer, lead scientist for NASA’s mars exploration program and program scientist for MSL, says. “So one of the big carry-forward technologies is the whole sky crane apparatus being able to get something that heavy to the surface. This whole system gets rid of the weight of a landing platform, it gets rid of a ramp that would be needed to get off the retro-rockets if it were to land on top of the rockets--we’ve stripped away all of the unnecessary things, and there’s a huge payoff there. It allows us to put something pretty heavy on the surface of mars.”
Can it scale to handle even larger payloads? It’s impossible to say without doing some very careful math and modeling, but on its face it seems feasible that we could scale up the sky crane by a factor of two, Meyer says. By a factor of ten? Maybe. The important thing is that NASA put a metric ton on another planetary body. Something that can accurately place that much weight elsewhere in the solar system could deliver future robots, pieces of a future human habitat, an energy source to power a fleet of robots--the possibilities are suddenly wide open. Unlike much of NASA’s previous landing technology, it’s a capability with lots of room to grow. Says MSL Project Scientist John Grotzinger of the sky crane: “I think this is the way that all landed Mars missions will be carried out.”