Lunar Prospector Status Report #86

June 11, 1999 - 1:00 p.m. EST (10:00 a.m. PST)

The Lunar Prospector spacecraft continues to collect good science data in
the extended mission orbit. Four of five science instruments are on: the
Gamma Ray Spectrometer (GRS), the Neutron Spectrometer (NS), the
Magnetometer (MAG), and the Electron Reflectometer (ER). Data continues to
be collected for the Doppler Gravity Experiment (DGE) as well.

The transmitter was turned off for short intervals 7 times this week during
eclipse periods when the propellant tank heater was on. The battery
voltage remained within green limits all week. Although the number of
heater events is slowly increasing (there were 24 events this week), the
battery load is decreasing as the heater on-time and the eclipses are both
getting shorter.

The MAG/ER was commanded to burst mode on 6/8 to collect high resolution
data for a short period of time.

All commands (30 total) executed normally this week.

Current spacecraft state (0000 GMT 6/11/99, DOY 162):

Orbit: 6407
Downlink: 3600 bps
Spin Rate:12.12 rpm

Spin Axis Attitude (ecliptic):
>Latitude: -88.9 deg
Longitude: 049 deg

Trajectory:
Periapsis Alt: 17.5 km
Apoapsis Alt: 42.5 km
Period: 111 min

Occultations: 49 minutes
Eclipses: 37 minutes
Propellant Remaining: 10.68 kg
The next orbit maintenance burn is scheduled for June 28, GMT (afternoon of June 27, PST).