RobotMe summary
Texas A&M researchers are developing RoboBall, an inflatable spherical robot intended to explore difficult lunar terrain. IEEE Spectrum describes Earth-based tests and a proposed mission concept in which a rover would release the ball near a crater.
The spherical form is designed to tolerate rolling and avoid the tipping problem faced by conventional vehicles. The concept targets terrain that could be dangerous for astronauts and difficult for wheeled explorers. It is a research proposal with ground testing, not a mission already exploring the Moon.