SpaceHopper: A Small-Scale Legged Robot for Exploring Low-Gravity Celestial Bodies
<|reference_start|>SpaceHopper: A Small-Scale Legged Robot for Exploring Low-Gravity Celestial Bodies: We present SpaceHopper, a three-legged, small-scale robot designed for future mobile exploration of asteroids and moons. The robot weighs 5.2kg and has a body size of 245mm while using space-qualifiable components. Furthermore, SpaceHopper's design and controls make it well-adapted for investigating dynamic locomotion modes with extended flight-phases. Instead of gyroscopes or fly-wheels, the system uses its three legs to reorient the body during flight in preparation for landing. We control the leg motion for reorientation using Deep Reinforcement Learning policies. In a simulation of Ceres' gravity (0.029g), the robot can reliably jump to commanded positions up to 6m away. Our real-world experiments show that SpaceHopper can successfully reorient to a safe landing orientation within 9.7 degree inside a rotational gimbal and jump in a counterweight setup in Earth's gravity. Overall, we consider SpaceHopper an important step towards controlled jumping locomotion in low-gravity environments.<|reference_end|>
@article{spiridonov2024spacehopper:,
    title={SpaceHopper: A Small-Scale Legged Robot for Exploring Low-Gravity
  Celestial Bodies},
    author={Alexander Spiridonov, Fabio Buehler, Moriz Berclaz, Valerio Schelbert,
  Jorit Geurts, Elena Krasnova, Emma Steinke, Jonas Toma, Joschua Wuethrich,
  Recep Polat, Wim Zimmermann, Philip Arm, Nikita Rudin, Hendrik Kolvenbach,
  Marco Hutter},
    journal={arXiv preprint arXiv:2403.02831},
    year={2024},
    archivePrefix={arXiv},
    eprint={2403.02831},
    primaryClass={cs.RO}
}