NASA’s Mars rover Curiosity was immobilised for six days in early May after a single rock became lodged under its right front wheel, forcing mission engineers to devise a remote “rock‑removal” procedure before the vehicle could resume its traverse of the Jezero crater region.
The incident occurred on May 3, when Curiosity was traveling east‑west along the rover’s planned path toward a scientifically promising target known as “Murray Ridge.” Telemetry indicated a rapid increase in wheel slip, and subsequent images confirmed that a sandstone boulder, estimated to be roughly 30 cm wide, had wedged itself between the wheel’s drive motor and the supporting “rocker‑bogie” suspension system. The blockage prevented the wheel from rotating, effectively halting the rover’s progress.
Mission controllers at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, initiated a series of diagnostic commands to assess the severity of the obstruction. Because Curiosity’s remote‑operated “wheel‑bounce” maneuver—used in previous wheel‑stuck events—proved ineffective, engineers elected to employ the rover’s robotic arm, known as the “Instrument Deployment System” (IDS), to push the rock clear of the wheel.
The IDS, equipped with a precise set of instruments and a 2‑meter‑long arm, was commanded to extend, grasp the boulder, and apply a calculated force in a series of incremental pushes. Over a period of 48 hours, the arm performed three distinct attempts, each monitored closely for signs of stress on the rover’s chassis. On May 9, the final push succeeded in dislodging the rock, allowing the right front wheel to regain full rotation. Subsequent mobility tests confirmed that all six wheels were operational, and Curiosity resumed its drive sequence at a reduced speed to mitigate further risk.
“This event underscores the challenges of autonomous navigation on a terrain that is both unknown and highly variable,” said JPL’s Curiosity Project Manager. “The successful use of the robotic arm to recover a stuck wheel demonstrates the robustness of the rover’s design and the ingenuity of the team.”
The six‑day delay impacted Curiosity’s science schedule, pushing back the start of a series of investigations into sedimentary layers that may preserve evidence of ancient Martian water activity. Nevertheless, the rover is expected to regain its original timeline within the next fortnight, thanks to a revised traversal plan that incorporates additional safety margins.
Curiosity, which has been operating on the Martian surface since 2012, continues to serve as a key platform for in‑situ geological analysis and atmospheric monitoring. The incident provides valuable data for future missions, including the Perseverance rover and upcoming sample‑return initiatives, highlighting the importance of redundant mobility systems and adaptable problem‑solving strategies in extraterrestrial exploration.
