NEAR Shoemaker Weekly Report – January 26, 2001

MISSION OPERATIONS:
 
The NEAR Shoemaker spacecraft began this past week in the 35 km circular orbit initiated December 13 @ 20:15 UTC with the successful execution of Orbit Correction Maneuver 20 (OCM 20).  After 6 weeks at this radius, the 35 km circular orbit, designed for X-Ray / Gamma-Ray Spectrometer (XGRS) science, was terminated this past Wednesday when the January Close Flyby Sequence was initiated.  This Close Flyby Sequence consists of three propulsive maneuvers in 5 day.  The first maneuver in this trio, Orbit Correction Maneuver 21 (OCM 21) was successfully executed this past Wednesday, January 24, @ 16:05 UTC, placing NEAR Shoemaker into a 35 km x 24 km elliptical orbit.  The spacecraft will remain in this orbit until January 28 @ 01:25 UTC, when Orbit Correction Maneuver 22 (OCM 22) lowers the periapsis to 19 km, allowing asteroid passes as low as 2.7 km altitude. Approximately 16.5 hours after executing OCM 22, Orbit Correction Maneuver 23 (OCM 23) will be performed at apoapsis, restoring the 35 km circular orbit.
 
Mission Operations planning activities have shifted from the January Close Flyby to the End of Mission activities.  Solid State Data Recorder (SSDR) management during the final descent to the asteroid will be paramount to MSI image retrieval.  Accordingly, several flight tests have been scheduled to demonstrate the recorder management technique.  Since results from the January 10th test were inconclusive due to weather problems at the DSN station, additional flight tests have been scheduled for February 2nd and 3rd.  The NEAR Laser Rangefinder (NLR) will be operated in its descent configuration during the February 2nd test to verify acceptable performance.
 
An End of Mission technical review of the descent sequence is scheduled for next Tuesday, January 30, @ 18:00 UTC.
 
The spacecraft subsystem configuration has not changed during this reporting period.
 
Except for the NIS, science activities conducted this week included Eros observations by the full instrument suite: MSI, MAG, XGRS and NLR.  Please consult science timelines for more details.
 
Upcoming Spacecraft Activities:
 
In addition to regular Eros Science and Optical Navigation, the following are operationally significant activities planned for the NEAR Shoemaker mission operation:
 
Jan 28 Eros Orbit Correction Maneuver 22  (35 km x 19 km elliptical orbit) Jan 28 Eros Orbit Correction Maneuver 23  (35 km orbit circularization) Feb 2 Eros Orbit Correction Maneuver 24  (Orbit Trim)
Feb 6 Eros Orbit Correction Maneuver 25  (Orbit Trim)
Feb 12 End of Mission Maneuvers