PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT NOTE = "Comments on the Lunar Prospector Level 0 CD-ROMs" PUBLICATION_DATE = 1999-06-23 END_OBJECT = TEXT END COMMENTS ON LUNAR PROSPECTOR LEVEL 0 CD-ROMS This document contains a cumulative set of comments and errors concerning the Lunar Prospector Level 0 data archive published on CD-ROMs. I. General Comments 1. Merged telemetry files In most cases, the first record of a merged telemetry file is the same as the last record of the previous file. There are, however, cases where there are time gaps between two merged telemetry files and, thus, no overlapping records. There are also a few cases where two files do not have these overlapping records. 2. PDS catalog objects The catalog objects on this volume for the five science instruments are somewhat brief. This is because at the time that the volume was released, published papers about the instruments were not available. When instrument papers are published by the Lunar Prospector Science Teams, the catalog objects will be revised and expanded. The revised catalog objects will be included on later volumes. Several of the Lunar Prospector catalog object files have been updated for Level 0 volume LP_0013 to include information about significant events in the Primary and Extended Missions. The revised catalog files include the mission, spacecraft, and data set files. 3. Uplink command files Occasionally a given command is listed twice by the software that generates the command files. This can be detected because the two commands are identical (same command and same transmit time). However, these duplicate commands were only transmitted once to the spacecraft. 4. Spacecraft Clock The LP spacecraft clock or frame counter increments once every 2 seconds. It is stored in a 24-bit register. This means that the clock will reset to zero after about 33.5 million seconds or about one year. The LP spacecraft clock reset on January 30, 1999 at about 12:09 UTC, which was early in the Extended Mission. Level 0 data files containing the reset clock counter are found on volumes LP_0013 and above. II. Comments of volume LP_0001 1. ATTITUDE.TAB file on volume LP_0001 Attitude determinations from 1/7/98 through 1/15/98 are based on Sun sensor data only. Determinations starting on 1/16/98 are based on a combination of Sun sensor data, Earth-Moon limb sensor data, and the definitive ephemeris. 2. Uplink command files on volume LP_0001 In command file C9802342.TAB on volume LP_0001, the MERHTROFF command transmitted at 1998-01-23T00:49:53 did not execute on the spacecraft because the command format was incorrect due to a configuration error in the command system at the Mission Control Center. III. Comments of volume LP_0003 1. ATTITUDE.TAB file on volume LP_0003 Attitude determinations from 3/1/98 through 3/3/98 are based on a combination of Sun sensor and Earth-Moon limb sensor data. Determinations from 3/4/98 through 3/31/98 are based only on Sun sensor data due to poor Earth-Moon limb sensor geometry 2. File names for sun pulse and merged telemetry files on volume LP_0003 PDS file names for the sun pulse and merged telemetry files are based on the date and hour for the start of the file. On volume LP_0003 there were two sun pulse and merged telemetry files that began in the same hour (hour 19 of 3/20/98). To avoid having files with the same name, the start hour used for one set was 19, whereas hour 20 was used for the second set. The files involved are: s9807919.b m9807919.b s9807920.b m9807920.b IV. Comments of volume LP_0004 1. ATTITUDE.TAB file on volume LP_0004 Attitude determinations from 4/1/98 through 4/12/98 and for 4/16/98 are based only on Sun sensor data due to poor Earth-Moon limb sensor geometry. Determinations for other times in April 1998 are based on a combination of Sun sensor and Earth-Moon limb sensor data. 2. Uplink command files on volume LP_0004 The commands listed in file C9811346.TAB did not reach the spacecraft due to a configuration error in the command system. V. Comments of volume LP_0005 1. ATTITUDE.TAB file on volume LP_0005 Attitude determinations from 5/3/98 through 4/9/98 are based only on Sun sensor data because of Earth interference with the Earth-Moon limb sensor. Also determinations for 5/31/98 are based only on Sun sensor data due to poor Earth-Moon limb sensor geometry. Determinations for other times in May 1998 are based on a combination of Sun sensor and Earth-Moon limb sensor data. 2. Revised format for MAG/ER data starting with volume LP_0005 On May 14, 1998, commands were sent to the Lunar Prospector spacecraft to reprogram onboard data processing and formatting in the MAG/ER instrument. The new data format is described in the MAGERFMT.PDF file found in the DOCUMENT directory. This file is a revision of Appendix G (LP MAG/ER Telemetry Format) of the Level 0 Data Product SIS document found in the LVL0SIS.PDF file. VI. Comments of volume LP_0006 1. ATTITUDE.TAB file on volume LP_0006 Attitude determinations from 6/1/98 through 6/30/98 are based only on Sun sensor data due to poor Earth-Moon limb sensor geometry. 2. Command file C9815961.TAB on volume LP_0006 In command file C9815961.TAB, the command "GHV1LEV, 206" was transmitted multiple times due to a command system configuration error at the mission control center. The command was transmitted three times incorrectly (and one of those commands is duplicated in the command file). The command system was reconfigured and the command transmitted at 20:46:24.7 was accepted by the spacecraft. VII. Comments of volume LP_0007 1. ATTITUDE.TAB file on volume LP_0007 Attitude determinations from 7/1/98 through 7/31/98 are based only on Sun sensor data due to poor Earth-Moon limb sensor geometry. VIII. Comments of volume LP_0008 1. ATTITUDE.TAB file on volume LP_0008 Attitude determinations from 8/1/98 through 8/31/98 are based only on Sun sensor data due to poor Earth-Moon limb sensor geometry. 2. Sun Pulse File s9823322.b The sun pulse file s9823322.b (and its label) is not included on volume LP_0008. This file would cover the time period of 1998-08-21T22:21 to 1998-08-23T03:12 UTC. The spacecraft was in eclipse during this time period and the spacecraft spin rate solutions are still being analyzed. This sun pulse file will be included on a later volume. IX. Comments of volume LP_0009 1. ATTITUDE.TAB file on volume LP_0009 Attitude determinations from 9/1/98 through 9/30/98 are based only on Sun sensor data. 2. Sun Pulse File s9826610.b The sun pulse file s9826610.b (and its label) is not included on volume LP_0009. This file would cover the time period of 1998-09-23T10:13 to 1998-09-23T16:36 UTC. The spacecraft spin rate solutions are still being analyzed. This sun pulse file will be included on a later volume. 3. Command files C9826116.TAB, C9826746.TAB, and C9827027.TAB Several command files on volume LP_0009 contain commands that were not received by the spacecraft. In C9826116.TAB the two pairs of XMTON and EXEC commands between 15:05:00 and 15:10:11 were not received by the spacecraft because the DSS antenna pointing was off the spacecraft. In C9826746.TAB the XMTON and EXEC commands between 06:24:00 and 06:24:02 and 08:22:00 and 08:22:02 were not received by the spacecraft because of a DSS problem. In C9827027.TAB the two pairs of XMTON and EXEC commands between 03:10:00 and 03:15:28 were not received by the spacecraft because of an uplink failure at the station. X. Comments of volume LP_0010 1. ATTITUDE.TAB file on volume LP_0010 Attitude determinations from 10/1/98 through 10/31/98 are based only on Sun sensor data. XI. Comments of volume LP_0011 1. ATTITUDE.TAB file on volume LP_0011 Attitude determinations from 11/1/98 through 11/30/98 are based only on Sun sensor data. 2. Command files C9830542.TAB, and C9830642.TAB Two command files on volume LP_0011 contain commands that were not properly executed by the spacecraft. In C9830542.TAB the first 4 commands between 11:10:17 and 12:00:34 were delayed because of a command system failure. In C9830642.TAB the 6 commands between 09:36:00 and 09:55:50 did not work. XII. Comments of volume LP_0012 1. ATTITUDE.TAB file on volume LP_0012 Attitude determinations from 12/1/98 through 12/31/98 are based only on Sun sensor data. XIII. Comments of volume LP_0013 1. ATTITUDE.TAB file on volume LP_0013 Attitude determinations from 1/1/99 through 1/31/99 are based only on Sun sensor data. 2. Sun Pulse File s9902903.b Sun pulse file s9902903.b (and its label) is not included on volume LP_0013. This file would cover the time period of 1999-01- 29T03:16 to 1999-01-29T08:51 UTC. The spacecraft was in eclipse during this time period and the spacecraft spin rate solutions are still being analyzed. This sun pulse file will be included on a later volume. 3. Command file C9903146.TAB This command file on volume LP_0013 contains two commands that were not properly received by the spacecraft. The two commands between 16:53:39 and 16:53:41 did not get into the spacecraft. XIV. Comments of volume LP_0014 1. ATTITUDE.TAB file on volume LP_0014 Attitude determinations from 2/1/99 through 2/28/99 are based only on Sun sensor data. 2. Sun Pulse File s9905611.b Sun pulse file s9905611.b (and its label) is not included on volume LP_0014. This file would cover the time period of 1999-02- 25T11:37 to 1999-02-25T15:40 UTC. The spacecraft was in eclipse during this time period and the spacecraft spin rate solutions are still being analyzed. This sun pulse file will be included on a later volume.