With all of the trouble with stuck Martian rovers I was pleased to come across some articles discussing some possible future designs of interplanetary explorers. On Mars one of the primary issues is the lack of speed of a rover due to the difficulty in traversing quite a varied landscape. The rovers typically move a hundreds of meters per day, on a good day, but might be lucky enough to get close to 1k. You can understand why the MRO is spending quite a lot of time generating high resolution images of the surface. Quite a bit of time is spent figuring out the best route. When you have to back track it can cost quite a few days, and while the current rovers are doing exceptionally well, not all future rovers may be so lucky. But it is not just Mars that we plan to explore. Our own Moon offers similar challenges along with Mercury, Venus and many of the moons of Saturn and Jupiter. Having to deal with rocks, gullies and sand are among the obvious issues, but lakes of Methane on Titan are also future challenges. Here are some of the possible future explorers.
SandBots
Moving on sand is difficult and when using wheels it is easy to get stuck if the wheels move at the wrong speed. Researchers are looking to mimick how lizards and cockroaches move over sand. SandBot is the smallest (2.3 kg) in a series of biologically inspired hexapedal robots. Sandbot is the concept of Daniel Goldman of the Georgia Institute of Technology in Atlanta whom I have quote below from his recent article in IEEE
“we have noticed that the lizard’s long toes sink deep into the sand at each step. It appears that this allows it to push off from sand that’s deeper and more solid than the less stable surface layer. The effect, preliminary evidence suggests, is that the sinking enables the lizard to run as if on hard ground, allowing it to maintain speeds up to 75 percent of its pace on solid ground. Desert animals deal with sand with different levels of success, and their techniques provide valuable clues for refining SandBot.”
Balloons
Balloons can fly one hundred times closer to the surface of a planet or moon than orbiters and can travel a thousand times further than rovers in a comparable period, thus providing views of much broader areas of the surface. Helium super-pressure balloons, currently under development for the Ultra Long Duration Balloon (ULDB), will fly more than 100 days and perhaps as long as a year here on Earth. Smaller super-pressure balloons carrying payloads of only a few pounds have already flown for as long as a year. From NASA “Using this technology, a future Mars balloon would deploy soon after a spacecraft entered the Mars atmosphere and would then rapidly inflate from a helium tank as it descended beneath a parachute. After inflation, the parachute and tanks would detach and the balloon would fly at a nearly constant altitude both day and night.”
SailBoats
Artists impression of a lakes on Titan
I blogged about a proposal to put a sailboat on Titan to explore the Methane lakes last month based on a proposal by Ellen Stofan. Titan has wind and rain, but its a chilly -180 Celsius where Ethane and Methane flow instead of liquid water in world which has been described as an eerie version of Earth. There are perhaps only a few destinations for such a device, but its still worth considering.
“We got funded to look at the possibility of sending a lake lander to Titan,” said Ellen Stofan, a geologist with Proxemy Research in Maryland. “Scientifically, it’s sort of a beyond obvious thing to do.”
Airplanes
Because the Martian (and many other planets and moons) atmosphere is so thin, taking off from the ground would require very big wings or a very fast take-off. One solution to this problem is to have the airplane drop off an entry vehicle as it is coming into the Martian sky. As the plane drops off, the wings would unfold and it would start flying, powered either by batteries or by gliding through the air. A likely place to fly airplanes would be in valleys or other interesting places where there is a lot to see over great distances.
AMES: Proposed Martian Airplane
My favourite is still the insect and lizard inspired sandbots. It might be a while before we move beyond the rovers, but until then it looks like there are plenty of concepts being worked on and the future looks like it will be an interesting step in explorer evolution.
SandBot 2
