The DS1 mission was terminated at 1:00:09 pm PST, December 18 2001. The ion drive had been in use for 677 days, and had expended 90% of the xenon it carried at launch. The mission had been been successfully extended to collect data from the comet Borrelly, but plans to further extend the mission to rendezvous in August 2002 with the asteroid named 1999 KK1 were not pursued due to limits on resources and finances.

Sources: Adios In Deep Space, by Marc D. Rayman,Mission Manager DS1, Pasadena - Dec 18, 2001