Mars has as much surface territory as all the land areas of Earth, and scientists have barely touched the planet at ground level, despite 35 years of lander and rover missions.
So maybe it’s time to send a hopper.
HOT GAS MAKES IT GO. The proposed "Mars hopper" scavenges carbon dioxide gas from the atmosphere, heats it, and uses the hot gas to jet the lander roughly a kilometer each time. With landing legs extended, the diameter is 4 meters, or 13 feet. (Image is Figure 1 from the paper.)
Hugo Williams and colleagues at the University of Leicester, working with Astrium Ltd. in the UK, the Centre for Space Nuclear Research in Idaho, and Oregon State University are proposing a new Mars Reconnaissance Lander vehicle expressly designed to cover a lot of ground — 200 kilometers (120 miles) or so — during a basic mission lasting four Earth years. Unlike slow-rolling rovers, the MRL would take kilometer-long jumps between points of interest. The spacecraft is described in a paper published August 3, 2011, in Planetary and Space Science.
As outlined, the Mars hopper would carry a small (16.5 kilogram, 36 pound) science payload, modeled after that carried by the Beagle 2 lander. (This is about the same as the science payload on each Mars Exploration Rover.) Instruments would include a stereo camera, a gas chromatograph mass-spectrometer, and a Mössbauer spectrometer. The hopper would spend at least a week at each landing site, studying the area while reloading its fuel supply.
The hopping power comes from a thruster that fires carbon-dioxide gas collected from the atmosphere by an air pump through a bed of pebbles preheated by a radioisotope.
(Cold gas would also work, but provide less thrust and a shorter hopping range.) The electrical power comes from a radioisotope Stirling-cycle generator.
Concepts for hopping vehicles have been proposed before, but this time the predicted vehicle performance is matched to a hypothetical mission traverse through an area along Hypanis Vallis. The region in question lies at the edge of the ancient highlands and includes one of the proposed landing sites for the Mars Science Laboratory.