We've put a rover on Mars, heck, we've got a few of them up there. What's the next step, before the inevitable invasion by humans? A helicopter obviously! Well, more specifically, drones that can help the poor ground-shackled rovers get a better idea of what lies ahead in their travels.
In a new video from NASA's Crazy Engineering series, JPL mechanical engineer Mike Meacham explains that reasons behind a Mars-capable drone and the problems the design team must overcome for the little guy to work:
You might think it's actually easier to fly one of these helicopters on Mars because it's 3/8's the gravity of Earth, but its 100 times less atmosphere ... once you lose that density, you've got to spin even faster, or get bigger rotor blades or get lighter.
The idea is that the drone can scout ahead, say if the rover encounters a cliff it will have to expend a lot of time and energy getting over. The drone can see if it's worth the effort and if so, what else the rover will have to tackle.
According Bob Balaram, JPL's chief engineer of mobility and robotics systems, the team has the following five issues to contemplate: atmospheric density, low system mass, autonomous flight, repeated takeoffs / landings and survivability. The current design calls for a one kilo, cube-shaped drone measuring 1.1m from each blade tip; with rotors that must spin 2400rpm to fly under Mars conditions (simulated in a vacuum chamber at 0.087 psi).
What are NASA's expectations? Along with a "bulletproof landing system", it'll have to be able to fly for a few minutes at least, says Balaram:
The system is designed to fly for 2-3 minutes every day. There's a solar panel on the top and that provides us with enough energy for that short flight, as well as to keep us warm throughout the night. So, in those 2-3 minutes, we expect to have daily flights of about half a kilometre.