thumb|upright=1.0|right|Artistic impression of NASA's DART spacecraft (below) approaching MUBLCOM (above) while orbiting over the eastern Pacific Ocean near Central America

DART, or Demonstration for Autonomous Rendezvous Technology, was a NASA spacecraft with the goal to develop and demonstrate an automated navigation and rendezvous capability. At the time of the DART mission, only the Roscosmos and JAXA had autonomous spacecraft navigation. Orbital Sciences Corporation (OSC) was the prime contractor for construction, launch and operation of the DART spacecraft with a project cost of US$110 million (2005).

On 14 April 2006, NASA announced that they would not release the investigation's report, citing that the report includes details protected by the International Traffic in Arms Regulations (ITAR).

On 15 May 2006, NASA released a public summary of the DART mishap investigation board report. NASA revealed that a critical navigation failure occurred when the DART and MUBLCOM spacecraft were about 200 meters apart, which precluded the full activation of the AVGS and allowed DART to approach MUBLCOM without accurate ranging information. A later failure of the collision avoidance system, which was relying upon inaccurate position and velocity information, allowed DART to ultimately collide with MUBLCOM at a relative speed of approximately 1.5 meters per second. Both spacecraft survived the collision without apparent damage. Throughout the autonomous proximity operations, DART used its limited propellant faster than anticipated, which caused "a premature end to the mission" 3 minutes 49 seconds after the collision. DART initiated its retirement programming, removed itself from the vicinity of MUBLCOM, and prepared for deorbit. After the collision, MUBLCOM "regained its operational status after an automatic system reset".

The DART Mishap Investigation Board determined that only 11 of the 27 defined mission objectives were partially or fully met, all of which related to the launch, early orbit, rendezvous, departure, and retirement phases. None of the 14 objectives related to the proximity operations phase were met.

Atmospheric entry

DART re-entered in the atmosphere of Earth around 08:32 UTC on 7 May 2016 over the south Pacific Ocean.

See also

  • Attitude control
  • Orbital Express
  • Spacecraft

References

  • DART at Marshall Space Flight Center
  • NASA Press release about the DART mishap 16 April 2005
  • Mishap overview and description of the cause 15 May 2006
  • DART Mishap Investigation Board Final Report 4 January 2007
  • NASA DART press kit April 2015