# SpaceHopper: A Small-Scale Legged Robot for Exploring Low-Gravity Celestial Bodies

arXiv: https://arxiv.org/abs/2403.02831 · HTML: https://mlsanity.com/paper/2403.02831/

## Key facts

- Cited by 4 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 5 Mar 2024.

## Built on by (most cited first, 4 of 4)

- [Sample-efficient and Scalable Exploration in Continuous-Time RL](https://mlsanity.com/paper/2510.24482/) (2025)
- [Olympus: A Jumping Quadruped for Planetary Exploration Utilizing Reinforcement Learning for In-Flight Attitude Control](https://mlsanity.com/paper/2503.03574/) (2025)
- [Towards Quadrupedal Jumping and Walking for Dynamic Locomotion using Reinforcement Learning](https://mlsanity.com/paper/2510.24584/) (2025)
- [Model-Based Reinforcement Learning for Control under Time-Varying Dynamics](https://mlsanity.com/paper/2604.02260/) (2026)

## Abstract (arXiv)

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.