Following the Sept. 10 update on CAPSTONE, mission owner and operator Advanced Space has provided an update on the mission. Read the full update from Advanced Space.
During or shortly after a planned trajectory correction maneuver on Sept. 8, CAPSTONE suffered an issue that caused the spacecraft to tumble beyond the capacity of the onboard reaction wheels to control and counter. CAPSTONE was attempting to communicate with the ground for approximately 24 hours before any telemetry was recovered. After data was received, mission controllers found that the spacecraft was tumbling, the onboard computer systems were periodically resetting, and the spacecraft was using more power than it was generating from its solar panels.
Using NASA’s Deep Space Network, the combined mission team – including Advanced Space, Terran Orbital, Stellar Exploration, and NASA – re-established contact with CAPSTONE and reconfigured the spacecraft’s systems to stabilize the situation while recovery plans are evaluated. CAPSTONE remains in safe mode and now is power positive, meaning that it is generating more power from the solar panels than the system is using. Navigation data collected after the issue began suggests the Sept. 8 trajectory correction maneuver was completed or nearly complete when the issue occurred. This means the spacecraft remains on the intended trajectory and on course to its near rectilinear halo orbit at the Moon.
While work is ongoing to diagnose the cause of the issue, the team is preparing CAPSTONE to attempt a detumble operation to regain attitude control of the spacecraft. This detumble operation was successfully demonstrated after separation from the launch upper stage in July. A successful detumble would give CAPSTONE control over its orientation, allowing it to orient the solar panels to the Sun to fully charge the batteries of the power used during the detumble. The spacecraft would then 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 to maximize the probability of a successful spacecraft operation.
Updates will be provided as available.