Lunar Prospector Status Report #90

July 09 , 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.

On July 4, the ER was commanded to burst mode for a short period, to collect higher resolution data over a particular location on the moon.

Only 2 commands were transmitted this week, both executed normally.

Current spacecraft state (0000 GMT 7/09/99, DOY 190):

Orbit: 6770
Downlink: 3600 bps
Spin Rate: 12.12 rpm

Spin Axis Attitude (ecliptic):
Latitude: -88.5 deg
Longitude: 048 deg

Trajectory:
>Periapsis Alt: 18.1 km
Apoapsis Alt: 41.9 km
Period: 111 min

Occultations: 47 minutes
Eclipses: none
Propellant Remaining: 9.51 kg

The next orbit maintenance burn is scheduled for July 26. It will be much smaller than previous burns, since the orbit only has to be maintained for a few days before setting up for the targeted impact scheduled for July 31. Plans are being finalized for the impact events, as well as for the lunar eclipse which will occur July 28.