December 20, 1998
The first rendezvous burn of the NEAR spacecraft’s bipropellant engine, scheduled for Dec. 20, at 5 p.m. EST, was not completed as planned. Except for brief communication shortly after the scheduled 20-minute burn period, contact with the spacecraft has been lost. Mission Operations is now working to reestablish contact based on expectations that NEAR has entered safe mode after the burn was aborted by the spacecraft.
December 21, 1998
At 5:20 p.m. today, Dec. 21, the NEAR mission team is still trying to reestablish communications with the spacecraft. Communications ceased at about 5:10 p.m. EST, Sunday, Dec. 20, during the first of four rendezvous burns that would put the spacecraft at optimum speed and location for a Jan. 10, 1999, rendezvous with asteroid 433 Eros.
Doppler data collected at about 5:40 p.m. Dec. 20, leads team members to believe that the spacecraft was transmitting at that time. Around-the-clock strategy sessions are being held to correct the problem. If communications are not established by midnight tonight it is highly unlikely that the spacecraft will go into orbit on January 10.
Because of the robust nature of the spacecraft design many alternatives are available to the team to ensure that the mission can weather schedule changes and still yield significant science return. Those alternatives will be reviewed once communications have been reestablished.