The next generation of Mars rovers may not rove at all, instead bouncing around the planet while harvesting carbon dioxide for fuel.
A new Mars hopper concept involves a carbon dioxide collection and compression system, which would take advantage of CO2 phase changes to produce thrust. The Martian atmosphere is rich in CO2, so a robotic hopper that can harvest indigenous fuels would provide greater range while also solving the problem of fuel transport.
Hugo Williams and colleagues at the University of Leicester in the UK propose using a radioisotope decay generator, used in spacecraft for decades, to warm a "thermal capacitor" and to power a CO2 compressor.
The system would suck up CO2 from the atmosphere, use heat from radioactive decay to put the gas under extremely high pressure until it liquefies, and then store it in a special tank. The hopper would also store extra radioactive heat in a thermal capacitor. When the hopper needs to move, the liquified CO2 comes in contact with the capacitor, turning it back into a gas; the expanding CO2 is used as a thruster to launch the hopper and softly land it again.
Williams and colleagues have been working on propulsion ideas for a Mars lander project including the aerospace giant Astrium, BBC reports. Hoppers could conceivably move farther and faster than NASA's Spirit and Opportunity rovers — Spirit is mired in the sand and Opportunity just hit the 25-kilometer (15.5 mile) mark after seven years of driving.
The team is not the first to propose a planetary hopper; a team from MIT and Draper Laboratory have proposed a planetary hopper that looks like our beloved Parrot AR.Drone, using ducted fans to control the hopper's height and a compressed nitrogen system to move it laterally.
But the British hopper solves the key problem of fuel, by taking advantage of Mars' abundance of CO2.
A paper on the hopper is outlined in the Proceedings of the Royal Society A.
this... doesnt really sound very reliable ive got to admit, or fixable if it were to fail :/
but using the martian atmosphere for fuel is an awesome idea! work on the delivery a bit, and test teSt TEST it well and then maybe i'll be a believer ;)
I think this article is a bit misleading... It seems to me that the CO2 from the atmosphere is not really being used as a fuel source, but rather as a means of propulsion. There is still a fuel source (radioactive decay generator) used to supply the power to the bot and convert the gasous CO2 into usable energy. Neat idea, but this bot still requires a energy creation device to be shipped with it... not exactly as revolutionary as the paper makes it seem
Well, they could do the same thing with solar panals, but radioactive decay heat is more dependable and longer lasting than the life of a cell. I don't think we are too worried about clean fuel on Mars at the moment.
I personally like the idea because it works on a system that is scaleable and useful. A compressed CO2 system could easily be used to power a "Mars buggy" for human transport (if we ever get there). Capturing CO2 from the environment to pump into bio-greenhouses will be an important step in colonization (the addition of new carbon and new O2 to the closed system).
The problem I'm seeing here is that Mars' atmospheric pressure is less than 1% of Earth's. Not only will it take a whole lot longer to fill a CO2 tank to liquefying pressures, but won't the storage tank have to be reinforced more than it would be on Earth, due to 99% less atmospheric pressure on the outside? Not sure if that makes a huge weight difference in the age of carbon-fiber and fiberglass wrapped bottles.
I don't see why we haven't set up a "robot base" on Mars now instead of just sending different rovers at different times. If we spent the money for a large RTG charging station, we could have sent a fleet of smaller rovers that go out and come back to recharge when their batteries started to run low. Or we could use an RTG to run a methane extractor in the areas where Mars produces lots of methane (have we figured out HOW it does yet?). Then the 'bots could simply fuel up, and there wouldn't be issues with reduced battery cycling.
I'm not the smartest guy in the class (in fact, probably the least smart), but... if we can do that in Mars... why can't we do that here...? I understand that it would take us a lot more energy to go into our atmosphere, but I would imagine certain possibilities like balloons as a solution...
Obviously, someone would have thought and asked about this. So, does someone care to educate me a little on what's wrong with my simple little theory?