NEAR-Shoemaker Report 09 Jun 00

MISSION OPERATIONS:

During this past week, NEAR Shoemaker remained in Operational Mode with
Flight Computer #1 and Attitude Interface Unit #2 in control of
spacecraft
attitude. Except for the Near-Infrared Spectrometer (NIS), the
spacecraft
instrument suite remained “ON” and operational this week.

NEAR Shoemaker is presently in a nominal 50 km circular orbit around
Eros.
The spacecraft entered this orbit April 30, 2000 at 16:15 UTC when
Orbit
Correction Maneuver 6 (OCM 6) was executed. According to the current
long
term trajectory plan, NEAR Shoemaker will remain in this orbit
conducting
Science observations until July 7, 2000 at 18:00 UTC when Orbit
Correction
Maneuver 7 (OCM 7) will initiate the 50 km x 35 km transfer orbit.

Since the next planned OCM is not scheduled until July 7, weekly
Momentum
Correction Maneuvers (MCM) are required to manage spacecraft system
momentum. Beginning May 10, these maneuvers are scheduled every
Wednesday
until June 28. The fifth MCM of this period, MCM 7, was successfully
executed this past Wednesday, June 7, at 16:00 UTC. The achieved
momentum
was well within operational tolerances, and the imparted delta V was
minor.

The XGRS was restored to an operational state Sunday May 28 at MET
134946483 (17:50:54 UTC) when the X-Ray and Gamma Ray high voltage
power
supplies were reconfigured. The XGRS has remained operational since.
The
source of the anomaly, which set the instrument Disaster Code and
autonomously turned the XGRS “OFF”, has been isolated and a fix
identified.

The NIS instrument remains disabled. A brief one-minute NIS survival
test
was executed this past Monday (DOY 157) to evaluate the health of the
instrument. Unfortunately, this test indicated the NIS state is the
same
as when disabled several weeks ago. Currently, there are no future NIS
turn “ON” plans.

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:

June 14 Momentum Correction Maneuver 8
July 7 Eros Orbit Correction Maneuver 7 (50x35km transfer orbit)
July 14 Eros Orbit Correction Maneuver 8 (35km orbit circularization)
July 24 Eros Orbit Correction Maneuver 9 (35x50km transfer orbit)
July 31 Eros Orbit Correction Maneuver 10 (50km orbit circularization)