British researchers are developing designs for a proposed Mars robot explorer which would travel around the Red Planet via rocket-propelled ballistic hops.
The aim is to give the Mars Hopper much greater reach than existing wheeled surface rovers. The 400kg vehicle would collect fuel between hops by compressing gas from the Martian atmosphere, and would be powered by a long-life radioisotope power source. Its improved mobility would enable it to study hundreds of locations over a lifetime of several years.
A team of scientists and engineers based at Leicester University's Space Research Centre is working on concept designs for the Mars Hopper's motor and on the ballistics involved. Published this month by the Proceedings of the Royal Society, they suggest that given the vehicle's relatively large payload, a hop range of 1km would be ideal.
"The Hopper is different from other rovers because of its power source," said Leicester's Dr Nigel Bannister. "In one mode the heat source generates electric power to drive a compressor to gather the carbon dioxide propellant from the Martian atmosphere. The heat source then stores thermal energy via a thermal capacitor and injects it into the propellant, which is accelerated out of a rocket nozzle to provide thrust."
"Our findings have resulted in a hop range of 1km, for a relatively large vehicle with a large suite of scientific instruments on board," added his colleague Dr Hugo Williams. "We also looked at the geometry and the best materials for the motor core.
"Our interest in the materials aspect is particularly relevant because we are also engaged in collaborative research with our colleagues in Materials Engineering here at Leicester, and Queen Mary University of London to explore how material properties of materials for use in the space nuclear systems of the future can be enhanced through novel processing and manufacturing techniques."