The primary malfunction of NASA's DART autonomous rendezvous technology demonstrator appears to have occurred in its GPS navigation system.

The partial failure of the 15 April mission is still being investigated, but the US space agency confirms the Orbital Sciences-built craft actually bumped into its target satellite, Mublcom, changing its orbit by between 5.5km (3.4 miles) and 9.5km.

DART was to have made a controlled rendezvous with Mublcom, coming to within 5m (16ft) of its target and performing stationkeeping manoeuvres.

A mishap investigation board established by NASA will report its findings at the end of next month. But it appears that a navigation system malfunction caused the spacecraft to adjust its flightpath, using excessive propellant and nitrogen gas in the attitude control system.

Source: Flight International