May 15 2006
From The Space Library
NASA’s DART (Demonstration of Autonomous Rendezvous Technology) Mishap Investigation Board (MIB), chaired by NASA engineer Scott D. Croomes, released a summary of its findings and recommendations regarding the DART spacecraft’s failure to complete its critical technology mission objectives. The MIB did not make the complete text of the official report public because it contained information protected by U.S. International Traffic in Arms Regulations and Export Administration Regulations. NASA had designed DART, successfully launching it on April 2005, to rendezvous with MUBLCOM (Multiple Paths, Beyond-Line-of- Sight Communications) and to perform maneuvers in proximity to that satellite. However, less than 11 hours into the mission, DART had collided with MUBLCOM. The MIB concluded that an error in the spacecraft’s global-positioning receiver had prevented DART from accurately determining its distance and speed in relation to MUBLCOM. Because of the incorrect on-board navigational data regarding its velocity, DART had failed to take effective action to avoid a collision and had responded with repeated excessive thruster firings. Shortly after the collision, the craft had determined that its pressurized nitrogen gas maneuvering fuel was low, and had initiated preprogrammed departure and retirement maneuvers. The MIB also found that “a lack of training and experience led the [DART] design team to reject expert advice because of the perceived risks involved in implementing the recommendations.” This error had “led to inadequate navigation system design and testing.” The MIB reported that the DART team could have addressed many of DART’s shortcomings if the team had reviewed and applied the documented data and experience of previous missions.
NASA, “NASA Releases Accident Report Summary,” media advisory M06-081, 15 May 2006, http://www.nasa. gov//home/hqnews/2006/may/HQ_M06081_dart_report.html (accessed 1 October 2009); NASA, “Overview of the DART Mishap Investigation Results,” http://www.nasa.gov/pdf/148072main_DART_mishap_overview.pdf (accessed 1 October 2009); Tariq Malik, “NASA Releases Summary of DART Mission Mishap,” Space.com, 16 May 2006, http://www.space.com/news/060515_dart_mishap_summary.html (accessed 24 June 2010; Space Daily, “Lots of Little Errors Caused DART Spacecraft Mishap,” 17 May 2006.
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