Jeffrey LewisTHUNK! DART, Meet MUBLCOM

NASA’s DART satellite may have bumped into the MUBLCOM satellite during a proximity operation:

NASA’s DART rendezvous satellite may have come in physical contact with its target spacecraft during its April 15 mission, which ended early when DART ran out of fuel, prime contractor Orbital Sciences Corp. said April 21.

In a conference call on Orbital Sciences’ first-quarter earnings, company President J.R. Thompson said the DART, or Demonstration of Autonomous Rendezvous Technology, satellite may have come much closer than 100 meters—as originally estimated—to its target, the MUBLCOM satellite.


“There is some data to suggest that indeed it got a lot closer [than 100 meters], and perhaps even touched the target,” Thompson said. “All other DART systems performed as expected.”

I guess my paper—Autonomous Proximity Operations: A Coming Collison in Orbit—was a little too literal.

The Air Force envisions autonomous proximity operations that will include inspecting foreign satellites. “Rules of the Road” for such operations might help prevent a serious incident in the future.


  1. Stephen Moore (History)

    NASA’s fact sheet on DART says it was to rely on both GPS data and on-board Advanced Video Guidance Systems data for the close-in maneuvers.

    The story you link to says that ‘noisy GPS system inputs’ were responsible for the rapid fuel loss onboard DART, so maybe the problem responsible for the wasted fuel also contributed to DART’s poor navigation.

    I guess we’ll know in July when the mishap report comes out.