Let’s go fly something on another planet.
Each new Mars mission has built on the successes of the last, from the Viking landers to the MER rovers to Curiosity's sophisticated Mars Science Laboratory. Now, NASA's Jet Propulsion Laboratory plans to up the stakes even further with a remote-controlled helicopter. After all, we've driven on and drilled into the Martian surface. It's high time we flew over it, too.
Obviously, piloting a camera-equipped copter on Mars is a cool idea on its own merits, and I already have some preliminary envy for the lucky person who ends up operating it. But it's also an efficient way to optimize the rover's course, by giving JPL a bird's eye view of the surrounding obstacles and points of interest. Indeed, the helicopter is estimated to triple the distance a rover could cover each day.
A recent episode of the new JPL webseries Crazy Engineering detailed the development and design of the 3.6 foot long Martian copters, and outlined some of the challenges of flight on Mars. For example, even though Mars has only 38 percent the surface gravity of Earth, getting airborne is tricky for a host of reasons.
"Crazy Engineering: Mars Helicopter." Credit: NASA/JPL/YouTube
"There is the challenge of the very low density of the atmosphere," said Bob Balaram, a roboticist at JPL, in the video. "There's the challenge of keeping the whole mass of the system small so that we don't overwhelm the lift capability of this system."
"It has to be autonomous in terms of being able to fly and maintain stable flight," he continued. "And then, this system has to repeatedly take off and land on natural rocky terrain like you see out here. And then, the other one is that it has to survive the harsh environment."
That's a lot of hurdles to clear, but Balaram's team has been developing the Mars helicopter for months, and have already built a full-scale prototype. The researchers simulated Martian conditions in a vacuum chamber and learned that in order to generate thrust in the anemic atmosphere, the copter's blades have to achieve 2,400 revolutions per minute. That would give the scout about two to three minutes of flight time, covering about half of a kilometer.
The next big challenge is figuring out a sure-fire landing system, because as Balaram points out, "landing is the riskiest part of any mission," and the copter will have to do it daily.
So while the Curiosity rover's landing featured seven minutes of terror, "we have seven seconds of terror everyday," said Balaram.
Even so, sending a helicopter to Mars is undoubtedly worth a daily heart rate spike. Its scientific import, paired with the novelty of flying on another planet, is just too enticing to resist.