CAPSTONE suffered an issue that caused the spacecraft to tumble beyond the capacity of the onboard reaction wheels to control and counter. This occurred during or shortly after a planned trajectory correction maneuver on September 8.
After this happened, CAPSTONE was attempting to communicate with the ground for approximately 24 hours before any telemetry was recovered. After data was received, mission controllers discovered that the spacecraft was tumbling and the onboard computer systems were periodically resetting. In addition, the spacecraft was using more power than it was generating from its solar panels.
The combined mission team – including Advanced Space, Terran Orbital, Stellar Exploration, and NASA – re-established contact with CAPSTONE using NASA’s Deep Space Network (DSN) and reconfigured the spacecraft’s systems to stabilize the situation while recovery plans are evaluated. CAPSTONE remains in safe mode. However, it is now power positive, meaning that it is generating more power from the solar panels than the system is using. According to navigation data collected after the issue began, the September 8 trajectory correction maneuver was likely completed or nearly complete when the issue occurred. As such, the spacecraft remains on the intended trajectory and is on course to its near rectilinear halo orbit at the Moon.
While work continues to diagnose the cause of the issue, the team is preparing CAPSTONE to attempt to regain attitude control of the spacecraft via a detumble operation. This detumble operation was successfully demonstrated after separation from the launch upper stage in July. If the detumble is successful, it would give CAPSTONE control over its orientation. This would allow it to orient the solar panels to the Sun to fully charge the batteries of the power used during the detumble. After that, the spacecraft would orient to the ground and await further instructions. These recovery operations will be further evaluated over the coming days. Recovery timing will be guided by the data and analysis available in order to maximize the probability of a successful spacecraft operation.
Updates will be provided as available.