For the second time a Cygnus reached orbit with only one solar array deployed. The spacecraft was cleared to proceed on the power available, berthed successfully, and delivered around 3,700 kilograms — a repeat performance of the fault and of the workaround.
The cargo included a set of new solar arrays for the station itself, continuing the upgrade that has been replacing the original panels degraded by two decades in orbit, along with experiments on plant genetics, mudflow behaviour and nanomaterials.
The spacecraft was named for Sally Ride, the first American woman in space, whose subsequent career was largely devoted to science education.
It remained berthed for several months and performed a reboost of the station before departing.
The recurrence of the array problem prompted a design review. Two consecutive partial deployments on a mature vehicle is the kind of pattern that suggests a systematic cause rather than bad luck, and the mechanism was subsequently modified.
