The NEAR-Shoemaker satellite continued to operate nominally this past week in orbit around the asteroid 433 Eros. NEAR-Shoemaker has been in Operational Mode with Flight Computer #1 and Attitude Interface Unit #2 in control.

All instruments with the exception of the MSI (see below) remained “ON” during this week. S/C attitude pointing continues to alternate between Eros nadir proximity pointing, Earth pointing, and Sun pointing as required to conduct Eros orbital operations. NEAR-Shoemaker completed its first month in Eros orbit on March 14.

NEAR-Shoemaker is presently in a 200 km by 209 km orbit around Eros. NEAR-Shoemaker will stay in this orbit conducting Science observations until April 2, 2000 when an Orbit Correction Maneuver will place the spacecraft in a 200 km x 100 km transfer orbit.

The March 15 Momentum Control Maneuver (MCM 1) successfully executed, biasing S/C momentum with minimal perturbing effects on the orbit.

This was a successful demonstration of the stand-alone propulsive momentum adjustment design required to manage S/C angular momentum during weeks when no Orbit Correction Maneuvers (OCM) are planned.

A repeat of this maneuver is planned for March 23.

MSI Execution Error

The Multispectral Imager (MSI) experienced another command execution error on March 13 at 03:52 UTC suspending image taking until March 14 when Mission Operations rebooted the MSI at 19:30 UTC. The investigation into this problem is ongoing.

Science activities conducted this week included Eros “high altitude” ~200 Km observations with the MSI, NIS, MAG, NLR and XGRS instruments. Please consult science timelines for more details.

Mission Operations held a review of a modified Earth Safe Macro that prevents instruments from being turned off during safing conditions when sufficient power is available.

The modified Earth Safe Macro will be uploaded to the spacecraft next week. Also reviewed was a new autonomy rule that will help safeguard the spacecraft in the event automatic wheel speed de-saturations are required.

Upcoming Spacecraft Activities: In addition to regular Eros Science and Optical Navigation, the following are operationally significant activities planned for the NEAR-Shoemaker future:


March 22 Propulsive Momentum Bias
April 2 Eros Orbit Correction Maneuver 3
(200 Km x 100 Km transfer orbit)