Katalyst Space's LINK spacecraft, sent to rescue NASA's Neil Gehrels Swift Observatory before it re-enters Earth's atmosphere, has run into fresh trouble during commissioning, tumbling in a multi-axis spin after two of its three reaction wheels failed. NASA also reported reduced functionality in the craft's cold-gas thruster system, and communications with LINK have become sporadic, though controllers remain in contact and say other subsystems are working normally. The setback matters because LINK has only a few months left to reach Swift before the ageing observatory is expected to fall out of orbit later this year.

The spin began over the weekend, and engineers are using LINK's electric propulsion thrusters — originally intended for the rendezvous phase — to arrest the tumble, with Katalyst saying it is "seeing the intended effect." Once stabilised, the team plans to update the guidance, navigation and control system for the craft's new configuration before revisiting approach and capture plans for Swift. This is not LINK's first commissioning hiccup: on 15 July, Katalyst reported earlier attitude-control and communications anomalies that were fixed with flight software patches. LINK launched earlier this month on the final Northrop Grumman Pegasus XL rocket, less than a year after the rescue contract was awarded, and Katalyst maintains the mission still has "a viable path to rendezvous with Swift."