Lunar Prospector Status Report #4

January 9, 1998 - 3:00 a.m. EST (12:00 midnight PST)

At the present time, the Lunar Prospector spacecraft is continuing to perform extremely well according to missions operations personnel. Activities today focused on calibration sequences for the science instruments, and analysis of the results of the second trajectory correction maneuver (TCM) executed yesterday. The results are "terrific" according to Marcie Smith, missions operations manager, and Lunar Prospector is now "very close to being right on target." If a third TCM is deemed necessary and is executed tomorrow night, it is anticipated that it will only be a 1 to 2 second burn, given the accuracy of the spacecraft's present course.

Station 24 at Goldstone experienced trouble locking up on the telemetry at the start of its pass today. For about 1.5 hours, the data was noisy and "glitching in and out of lock." After the subcarrier frequency was adjusted by a modest amount, the station was able to lock up and stay in solid lock. A telecon tomorrow with the Deep Space Network (DSN) engineer will clarify procedures designed to prevent this situation in the future. Due to the rolling storage of data, 53 minutes of this data will be corrected by data processing.

Commanding today consisted of science configuration and calibration commanding, and the execution of the reorientation maneuver placing the spacecraft into its attitude for Lunar Orbit Insertion (LOI).

At this time, the spacecraft is ready for LOI -- it is at the right attitude and spin period, and on course. A very small velocity trim may be executed tomorrow night. The spacecraft has all 5 instruments up and operating and collecting good data. To date, 250 commands have been sent to the spacecraft and all have executed normally.

David Morse
Ames Research Center
Moffett Field, CA 94035