A spool-shaped robot could one day rappel into steep craters on other planets or moons, anchored to another spacecraft by a rope. The craft, which would descend to its targets from an airborne balloon or emerge from the belly of a larger rover, is being described as a 'tethered marsupial'.
Engineers from NASA's Jet Propulsion Laboratory and students at the California Institute of Technology have designed and tested a versatile, low-mass robot that can rappel off cliffs, travel nimbly over steep and rocky terrain, and explore deep craters. This prototype rover, called Axel, might help future robotic spacecraft better explore and investigate foreign worlds such as Mars. On Earth, Axel might assist in search-and-rescue operations.
The Axel rover system is a family of platforms aimed at providing versatile mobility for scientific access and human-oriented exploration of planetary surfaces in the solar system.