The ERNEST rover traveled 16 miles in 37 hours — over 10 times faster than NASA's Perseverance rover on Mars.

ERNEST: A New Breed of Lunar and Planetary Rover

A prototype four-wheel rover, designated ERNEST (Exploration Rover for Navigating Extreme Sloped Terrain), has completed field tests and demonstrated autonomous navigation capabilities. Developed at NASA's Jet Propulsion Laboratory (JPL), the rover is designed as a testbed for autonomy software intended for future lunar and planetary missions.

In March 2026, ERNEST underwent field testing in the Colorado Desert near Plaster City, California. During the tests, the rover traveled approximately 16 miles over 37 hours of drive time. This speed is more than 10 times the pace at which NASA's Perseverance rover navigates on Mars.

Engineers monitored the rover during dusk, dawn, and nighttime hours to simulate lighting conditions found in polar lunar regions, which feature large terrain shadows. Photographs from the test show the rover traveling toward its shadow, team members setting up illuminators at night, and the rover with one wheel on a rock.

Technical Development

The ERNEST team added a rectangular head mounted on a 4.5-foot-tall (1.4-meter-tall) mast to the rover. Hardware assembly was completed in September 2024, though the rover initially required a human operator for control.

Engineers used reinforcement learning to train the rover to navigate autonomously. A high-fidelity virtual testing environment was developed by the Dynamics and Real-Time Simulation Laboratory at JPL. Engineers recorded the response of actual rover hardware to various terrains, then used that data to improve the simulator. Thousands of hours of simulated tests were completed over a single weekend using a high-performance computing cluster.

After months of virtual training, the rover demonstrated autonomous driving over sand ripples, rubble piles, steps, and steep slopes in JPL's Mars Yard. ERNEST has since completed many such courses.

Funding and Management

Work on ERNEST began in 2022, with initial support from JPL internal research and development funds. Current funding comes from NASA's Mars Exploration Program and the Exploration Science Strategy Integration Office under the Science Mission Directorate. Caltech manages JPL for NASA.

Future Development

According to JPL, the ERNEST team is starting a new autonomy project that integrates active suspension with longer-range intelligent navigation. The stated goal is to enable ERNEST to plan efficient paths, tackling surmountable obstacles and circumnavigating hazardous ones. These capabilities could contribute to future rover missions on Mars or the Moon.