spacetoday.net: DART mission ends prematurely

Posted: Sun, Apr 17, 2005, 1:18 PM ET (1718 GMT)
DART spacecraft illustration (OSC)

A NASA spacecraft launched Friday to test automated rendezvous and docking technologies terminated its mission ahead of schedule Saturday after discovering it was low on propellant. The Demonstration of Autonomous Rendezvous Technology (DART), launched Friday by a Pegasus XL, started its 24-hour mission to rendezvous with an existing inactive satellite, MUBLCOM, as planned Friday night, approaching within 90 meters of the spacecraft without any guidance from humans on the ground. The spacecraft was then supposed to make several approaches to within five meters of MUBLCOM to test docking techniques, but DART aborted that plan when its computers determined that it did not have enough propellant remaining to carry out the maneuvers. Instead, DART drafted away from MUBLCOM and later fired its thrusters in an end-of-mission maneuver designed to lower its orbit and speed up its eventual delay into the atmosphere. Project officials didn't know if the spacecraft did, in fact, have a leak of other problem that caused it to run out of propellant prematurely, or if a faulty sensor or computer glitch was the cause. An investigation board will be convened to determine the cause of the partial failure.