Katalyst Space's LINK spacecraft is having some attitude problems on its way to rescue NASA's Neil Gehrels Swift Observatory, resulting in a multi-axis spin and loss of communications.
LINK has three reaction wheels for attitude control, pointing, and stability, but the company said two are currently not operable. NASA reported some loss of functionality in its cold-gas thruster system as well.
LINK remains in contact with its controllers despite the sporadic communications, and its other major subsystems are operating as expected.
The problems began over the weekend, and the team is using LINK's electric propulsion thrusters to halt the spin. If it can restore a stable attitude, Katalyst will update the guidance, navigation, and control system for the spacecraft's new configuration before considering revised plans to approach and capture Swift.
LINK was built to rescue Swift before the observatory re-enters Earth's atmosphere. Less than a year passed between the contract award and its launch earlier this month aboard the final Northrop Grumman Pegasus XL rocket. Katalyst then began commissioning, deploying the solar arrays, generating power, and checking the vehicle's systems.
The commissioning hasn't gone entirely smoothly. On July 15, the company reported: "Early in commissioning, Mission Operations identified attitude control and communications anomalies during flight operations.
"The team implemented flight software patches and operational updates that restored reliable communications and enabled three-axis stabilized attitude control, allowing LINK to accurately point and orient itself in space."
MORE CONTEXT
Shortly before acknowledging the latest issue, Katalyst stated in a LinkedIn post that "LINK has been gradually increasing the duration of its thruster burns to prepare for the longer, multi-hour burns it will execute in the rendezvous phase."
Katalyst Space did not explain why two of LINK's three reaction wheels are not operable. The team is instead using electric propulsion thrusters intended for the rendezvous phase to stabilize the tumbling spacecraft.
With Swift expected to deorbit later this year, LINK has only a few months in which to reach it. Katalyst said it was "seeing the intended effect" from the thrusters, adding: "The mission remains active and we continue to believe that with these changes, LINK has a viable path to rendezvous with Swift." ®
