PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT NOTE = "Comments on the LRO SPICE Archive" PUBLICATION_DATE = 2020-02-21 END_OBJECT = TEXT END COMMENTS ON THE LRO SPICE DATA ARCHIVE ====================================== This document contains comments and errata concerning the LRO SPICE Data Archive. 1. Text Kernel File Format -------------------------- All SPICE text kernel files (LSK, PCK, SCLK, IK, FK) provided on these volumes have lines terminated by only (UNIX convention.) This is dictated by NAIF's archiving approach to include a consistent set of UNIX binary (IEEE architecture) and text ( only for end of line marker) kernels on the archive volumes. However, the format of the text kernels is specified in their associated labels as ASCII (INTERCHANGE_FORMAT = ASCII.) This is a violation of the PDS standard stating that lines in ASCII files must be delimited by the combination of . This line termination treatment is standard practice for SPICE volumes in the PDS. 2. Use of SPACECRAFT_NAME in the Labels --------------------------------------- PDS labels for SPICE kernels provided in this data set contain the deprecated keyword SPACECRAFT_NAME instead of the keyword INSTRUMENT_HOST_NAME. This is standard practice for SPICE volumes in the PDS and is dictated by NAIF's archiving approach to make SPICE archives for more recent missions consistent with SPICE archives for older missions, for which use of SPACECRAFT_NAME was legitimate. 3. Values of INSTRUMENT_NAME in the Labels ------------------------------------------ PDS labels for SPICE kernels provided in this data do not set the keyword INSTRUMENT_NAME to "SPICE KERNELS", that is the name of the instrument described by the instrument catalog file SPICE_INST.CAT provided in the data set. Instead this keyword is set to either "N/A" or the name(s) of the instrument(s) or structure(s), the geometric parameters of which a particular kernel file provides. While this error does prevent the individual data products from being associated with the "SPICE KERNELS" instrument, it does not affect usability of the SPICE data provided in this data set in any way because the SPICE toolkit does not use any information from the PDS label to access the data. The other side of this error is that the data set does not include instrument catalog files for the following instruments named in the INSTRUMENT_NAME keyword in the PDS labels: "LRO ORBITER "LRO SOLAR ARRAY" "LRO HIGH GAIN ANTENNA" "COSMIC RAY TELESCOPE FOR THE EFFECTS OF RADIATION" "DIVINER LUNAR RADIOMETER EXPERIMENT" "LYMAN ALPHA MAPPING PROJECT" "LUNAR EXPLORATION NEUTRON DETECTOR" "LUNAR ORBITER LASER ALTIMETER" "LUNAR RECONNAISSANCE ORBITER CAMERA" "MINI-RF LRO" 4. Missing FILE_RECORDS Keyword in the Binary Kernel Labels ----------------------------------------------------------- All labels for binary SPICE kernels provided in this data set are missing the FILE_RECORDS keyword, which is required because these labels have the RECORD_TYPE keyword set to FIXED_LENGTH. While this error violates the PDS standards, it does not affect usability of the SPICE data provided in this data set in any way because the SPICE toolkit does not use any information from the PDS labels to access the data. 5. Incorrect Mission Phase Values in the Comment Area ----------------------------------------------------- The MISSION_PHASE_NAME keywords in the copies of the PDS labels embedded at the top of the comment areas of the DLRE CK files and EK files covering October-December 2010 are incorrectly set to 'NOMINAL MISSION'. These keywords provided in the detached PDS labels are correctly set to 'SCIENCE MISSION'. 6. Minor Problems in DLRE CK Labels ----------------------------------- The labels for the following CK files data/ck/lrodv_2010365_2011032_v01.bc data/ck/lrodv_2011120_2011152_v01.bc have blank DESCRIPTION values and are not embedded at the top of the comment areas in the CK files. These labels are also missing an END statement. 7. Adjusting the start and end times for data sampling ------------------------------------------------------ The sample dates for previous releases has been the end of month to end of month. The release schedule indicated it should be mid month to mid month. Therefore in release 007 this start day is March 31st (90) in accordance with the old schedule, and ends on July 15th (165) in accordance with the release schedule; resulting in this release spanning two fewer weeks than expected. 8. Sunsafe induced gaps ------------------------------------------------------ During the period of 2012-09-04 03:58:28 to 2012-09-04 17:09:47 LRO entered a sunsafe period. The data from that time period could not be recovered. Both the V01 and the 10Hz V02 have the same gaps. During the period of 2013-11-26 00:00:31 to 2013-12-03 00:01:07 LRO entered a sunsafe period. The data from this time period is intermittent and some could not be recovered. 9. Ground System induced gaps ------------------------------------------------------ During the period of 2014-01-27 00:45:45 to 2014-01-27 01:01:11 the ground system experienced a failure in a storage device which caused loss of data which is unrecoverable. The v02 CK contains a gap in coverage from 2014-01-27 00:44:59 to 2014-01-27 01:02:00. The HGA and SA orientation CKs covering DOY 261, 2014-09-18 have the following irrecoverable gaps in coverage: from 2014-09-18T00:20:27.79385 until 2014-09-18T02:18:55.99339 from 2014-09-18T04:17:23.79247 until 2014-09-18T06:15:50.99374 from 2014-09-18T08:14:18.79401 until 2014-09-18T10:12:46.99413 from 2014-09-18T12:11:14.79409 until 2014-09-18T14:09:42.99324 from 2014-09-18T16:08:10.79416 until 2014-09-18T18:06:38.99424 from 2014-09-18T20:05:05.79430 until 2014-09-18T22:03:32.99406 10. Gaps due to Lunar Eclipse Operations ------------------------------------------------------ During the period of 2014-04-15 23:59:54 to 2014-04-16 00:00:09, the spacecraft was undergoing a total Eclipse. Following the eclipse, data was stored in a different way to avoid filling the SSRs. This data is non recoverable. The following irrecoverable gaps in the Solar Array (SA), High Gain Antenna (HGA), and Spacecraft (SC) CK files are from a large gap in White Sands Ka-Band contacts from 2022-05-15 08:41:04 to 2022-05-17 06:32:04 due to critical lunar eclipse operations. A total of 10 spacecraft housekeeping files were permanently deleted to prevent an SSR3 overflow during this gap. Gap start time, UTC Gap stop time, UTC Duration, sec ------------------------- ------------------------- ------------- 2022-05-15T07:12:03 2022-05-15T16:57:08 35105.000000 2022-05-16T12:27:20 2022-05-16T22:12:29 35109.000000 11. Incorrect Mission Phase Name Values in the Labels ----------------------------------------------------- The MISSION_PHASE_NAME keyword in the labels for kernels covering Extended Science Mission, 2nd Extended Science Mission, and 3rd Extended Science Mission is set to "EXTENDED MISSION" instead of "EXTENDED SCIENCE MISSION", "SECOND EXTENDED SCIENCE MISSION", and "THIRD EXTENDED SCIENCE MISSION". 12. Attitude Error in "v01" Spacecraft CKs ----------------------------------------------------- The ground system attitude reconstruction process used by the LRO project from the beginning of the mission up to 2015-042 could not correctly determine the spacecraft attitude at certain times when the spacecraft was offpointed. Because of that some of the "v01" spacecraft orientation CKs with coverages falling within the 2009-170 to 2015-042 range, added to the archive in releases 0001 to 0022, had incorrect spacecraft attitude during a small number of intervals lasting from a few to a few tens of minutes, with the errors at times reaching many tens of degrees. In February 2015 the project fixed the attitude reconstruction software and started producing spacecraft CKs with correct attitude at all times. For times after 2014-349, starting with release 0022, these CKs continued to be added to the archive as "v01" files. For times between 2009-170 and 2014-349, they were added to the archive as "v02" files, fully superseding the "v01" files already in the archive. The "v02" files were added to the archive in batches, starting with the first set covering 2014-074 to 2014-349 added in release 0024. Release 0026 covers 2012-214 to 2014-074 excluding 2012-245 to 2012-255 and 2013-325 to 2013-345. Release 027 covers 2012-001 to 2012-168 excluding 2012-132 to 2012-142. Release 028 covers 2012-132 to 2012-142, 2012-168 to 2012-214, and 2012-245 to 2012-255. To indicate intervals of significantly incorrect attitude in the "v01" files, this table lists all time intervals within the range covered by the "v02" files during which the correct attitude in the "v02" spacecraft CKs differs from the incorrect attitude the "v01" spacecraft CKs by more than 0.0012 radians: 2012-01-17T15:06 to 2012-01-17T15:06 2012-03-22T02:31 to 2012-03-22T20:02 2012-06-15T02:55 to 2012-06-15T02:58 2012-06-15T04:54 to 2012-06-15T04:57 2012-06-15T08:52 to 2012-06-15T08:55 2012-06-15T10:51 to 2012-06-15T10:54 2013-06-14T00:55 to 2013-06-14T01:01 2013-06-14T02:30 to 2013-06-14T02:38 2013-06-14T02:50 to 2013-06-14T02:53 2013-06-14T04:29 to 2013-06-14T04:37 2013-06-14T04:51 to 2013-06-14T04:58 2013-06-14T06:29 to 2013-06-14T06:35 2013-06-14T06:48 to 2013-06-14T06:55 2013-06-14T08:27 to 2013-06-14T08:34 2013-06-14T08:48 to 2013-06-14T08:54 2013-06-14T10:47 to 2013-06-14T10:52 2013-06-14T12:25 to 2013-06-14T12:30 2013-06-14T12:46 to 2013-06-14T12:50 2013-06-14T14:26 to 2013-06-14T14:28 2013-06-14T14:45 to 2013-06-14T14:48 2013-06-14T16:41 to 2013-06-14T16:46 2013-07-16T10:33 to 2013-07-16T11:14 2013-08-10T14:54 to 2013-08-10T15:55 2013-08-11T08:41 to 2013-08-11T09:41 2013-08-18T20:24 to 2013-08-18T21:01 2013-08-18T21:03 to 2013-08-18T21:09 2013-08-31T17:27 to 2013-08-31T17:27 2013-09-03T18:00 to 2013-09-03T18:24 2013-09-16T14:34 to 2013-09-16T15:22 2013-10-02T09:23 to 2013-10-02T09:36 2013-10-02T09:40 to 2013-10-02T09:47 2013-10-11T12:33 to 2013-10-11T12:45 2013-10-11T12:49 to 2013-10-11T12:57 2013-10-12T12:16 to 2013-10-12T12:27 2013-10-12T12:31 to 2013-10-12T12:39 2013-10-15T17:17 to 2013-10-15T17:25 2013-10-15T17:31 to 2013-10-15T17:38 2013-10-16T16:58 to 2013-10-16T17:05 2013-10-16T17:12 to 2013-10-16T17:19 2013-10-18T12:23 to 2013-10-18T12:34 2013-10-18T12:38 to 2013-10-18T12:46 2013-10-19T16:01 to 2013-10-19T16:14 2013-10-19T16:18 to 2013-10-19T16:26 2013-10-20T16:02 to 2013-10-20T16:08 2013-10-21T15:25 to 2013-10-21T15:39 2013-10-21T15:42 to 2013-10-21T15:50 2013-10-22T13:10 to 2013-10-22T13:21 2013-10-22T13:26 to 2013-10-22T13:33 2013-10-23T13:10 to 2013-10-23T13:15 2013-10-24T18:47 to 2013-10-24T18:53 2013-10-26T02:04 to 2013-10-26T02:18 2013-10-26T02:21 to 2013-10-26T02:29 2013-10-26T19:51 to 2013-10-26T20:04 2013-10-26T20:08 to 2013-10-26T20:15 2013-10-27T13:37 to 2013-10-27T13:50 2013-10-27T13:54 to 2013-10-27T14:02 2013-10-27T23:29 to 2013-10-27T23:43 2013-10-27T23:46 to 2013-10-27T23:54 2013-10-28T13:19 to 2013-10-28T13:32 2013-10-28T13:36 to 2013-10-28T13:44 2013-10-28T23:11 to 2013-10-28T23:25 2013-10-28T23:28 to 2013-10-28T23:36 2013-10-29T13:01 to 2013-10-29T13:14 2013-10-29T13:18 to 2013-10-29T13:25 2013-10-29T20:55 to 2013-10-29T21:08 2013-10-29T21:12 to 2013-10-29T21:19 2013-10-30T16:40 to 2013-10-30T16:53 2013-10-30T16:57 to 2013-10-30T17:05 2013-10-31T16:20 to 2013-10-31T16:35 2013-10-31T16:37 to 2013-10-31T16:46 2013-11-01T02:12 to 2013-11-01T02:20 2013-11-01T04:12 to 2013-11-01T04:26 2013-11-01T04:29 to 2013-11-01T04:37 2013-11-01T16:03 to 2013-11-01T16:17 2013-11-01T16:20 to 2013-11-01T16:28 2013-11-02T09:50 to 2013-11-02T10:03 2013-11-02T10:06 to 2013-11-02T10:14 2013-11-03T01:35 to 2013-11-03T01:52 2013-11-03T01:54 to 2013-11-03T02:04 2013-11-03T17:23 to 2013-11-03T17:40 2013-11-03T17:42 to 2013-11-03T17:52 2013-11-04T13:10 to 2013-11-04T13:25 2013-11-04T13:28 to 2013-11-04T13:36 2013-11-05T03:00 to 2013-11-05T03:15 2013-11-05T03:18 to 2013-11-05T03:26 2013-11-05T14:51 to 2013-11-05T15:06 2013-11-05T15:09 to 2013-11-05T15:17 2013-11-08T05:59 to 2013-11-08T06:23 2013-11-08T06:29 to 2013-11-08T06:29 2013-11-09T03:42 to 2013-11-09T04:14 2013-11-09T04:16 to 2013-11-09T04:20 2013-11-11T10:56 to 2013-11-11T11:31 2013-11-12T06:40 to 2013-11-12T07:10 2013-11-12T07:15 to 2013-11-12T07:16 2013-11-14T04:05 to 2013-11-14T04:41 2013-11-17T07:41 to 2013-11-17T07:45 2013-11-18T17:16 to 2013-11-18T17:21 2013-11-20T10:46 to 2013-11-20T10:51 2013-12-21T01:41 to 2013-12-21T04:07 2013-12-23T18:03 to 2013-12-23T18:31 2013-12-25T01:09 to 2013-12-25T03:08 2013-12-29T21:10 to 2013-12-29T21:27 2013-12-30T04:45 to 2013-12-30T04:54 2013-12-30T06:35 to 2013-12-30T06:55 2013-12-31T06:27 to 2013-12-31T06:35 2013-12-21T01:41 to 2013-12-21T04:07 2013-12-23T18:03 to 2013-12-23T18:31 2013-12-25T01:09 to 2013-12-25T03:08 2013-12-28T00:43 to 2013-12-28T00:46 2013-12-29T21:10 to 2013-12-29T21:27 2013-12-30T04:45 to 2013-12-30T04:54 2013-12-30T06:35 to 2013-12-30T06:55 2013-12-31T06:27 to 2013-12-31T06:35 2014-01-01T02:13 to 2014-01-01T02:20 2014-02-23T05:06 to 2014-02-23T05:29 2014-02-26T21:18 to 2014-02-26T21:47 2014-02-27T23:46 to 2014-02-27T23:47 2014-02-28T02:36 to 2014-02-28T03:13 2014-02-28T03:20 to 2014-02-28T03:20 2014-03-02T15:19 to 2014-03-02T15:39 2014-03-02T15:47 to 2014-03-02T15:47 2014-03-03T18:09 to 2014-03-03T18:24 2014-03-03T18:27 to 2014-03-03T18:52 2014-03-03T22:07 to 2014-03-03T22:48 2014-03-04T02:23 to 2014-03-04T02:29 2014-03-04T02:31 to 2014-03-04T02:40 2014-03-13T00:32 to 2014-03-13T01:29 2014-03-13T18:22 to 2014-03-13T18:39 2014-03-13T18:42 to 2014-03-13T19:15 2014-03-17T09:47 to 2014-03-17T09:54 2014-04-17T16:35 to 2014-04-17T18:37 2014-04-18T16:40 to 2014-04-18T18:25 2014-04-19T16:52 to 2014-04-19T18:01 2014-04-20T16:01 to 2014-04-20T17:49 2014-04-21T01:48 to 2014-04-21T03:40 2014-04-21T09:42 to 2014-04-21T11:36 2014-05-31T04:44 to 2014-05-31T06:05 2014-05-31T07:52 to 2014-05-31T09:00 2014-05-31T09:51 to 2014-05-31T10:13 2014-05-31T10:15 to 2014-05-31T10:52 2014-05-31T10:54 to 2014-05-31T10:58 2014-05-31T11:56 to 2014-05-31T12:13 2014-05-31T12:16 to 2014-05-31T12:52 2014-05-31T13:37 to 2014-05-31T15:06 2014-06-10T09:18 to 2014-06-10T09:23 2014-06-10T09:25 to 2014-06-10T10:19 2014-06-10T11:22 to 2014-06-10T12:14 2014-06-20T02:23 to 2014-06-20T02:35 2014-06-20T02:40 to 2014-06-20T03:41 2014-06-20T04:21 to 2014-06-20T04:37 2014-06-20T04:39 to 2014-06-20T05:41 2014-06-21T02:06 to 2014-06-21T02:19 2014-06-21T02:24 to 2014-06-21T03:28 2014-06-22T01:16 to 2014-06-22T03:14 2014-06-23T01:02 to 2014-06-23T03:00 2014-06-24T00:46 to 2014-06-24T02:46 2014-06-28T09:41 to 2014-06-28T11:40 2014-08-22T01:54 to 2014-08-22T03:31 2014-08-22T03:38 to 2014-08-22T04:24 2014-09-01T18:36 to 2014-09-01T18:55 2014-09-05T10:42 to 2014-09-05T10:46 2014-09-05T11:00 to 2014-09-05T12:27 2014-09-05T12:39 to 2014-09-05T12:47 2014-09-05T12:57 to 2014-09-05T14:19 2014-09-05T14:38 to 2014-09-05T14:45 2014-09-05T15:02 to 2014-09-05T15:03 2014-09-05T15:06 to 2014-09-05T15:06 2014-09-08T00:13 to 2014-09-08T00:26 2014-09-15T08:45 to 2014-09-15T08:50 2014-10-13T01:57 to 2014-10-13T02:35 13. Gaps due to SSR3 overfill during GOES-R WS1 antenna priority ---------------------------------------------------------------- During the period of 2016-12-07 10:36:37 to 2016-12-07 23:26:36, the GOES-R mission had priority over WS1 antenna use. LRO's SSR3 partition filled to capacity after a 44 hour gap in Ka-band downlink opportunities. This data is unrecoverable. 14. Gaps corresponding to the ascending node crossings ------------------------------------------------------ The following irrecoverable gaps in the Solar Array (SA) and High Gain Antenna (HGA) orientation CK files are due to an issue in generating AGS APID seqprt files for times around selected ascending node crossings: Gap start time, UTC Gap stop time, UTC Duration, sec ------------------------- ------------------------- ------------- 2019-04-10T17:47:15.82951 2019-04-10T17:49:48.43051 152.600998 2019-04-10T19:44:20.83041 2019-04-10T19:47:18.62940 177.798987 2019-04-10T21:41:24.83076 2019-04-10T21:43:33.03076 128.199998 2019-04-10T23:38:28.83046 2019-04-10T23:40:29.82946 120.999002 2019-05-05T18:37:42.94066 2019-05-05T18:45:07.94066 445.000000 2019-05-05T20:34:42.93965 2019-05-05T20:42:38.94066 476.001010 2019-05-05T22:31:42.94066 2019-05-05T22:38:06.54166 383.601000 ------------------------- ------------------------- ------------- 15. EK files for August and September 2019 ------------------------------------------------------ Weekly EK files for August and September 2019 (starting on August 11 through October 3) were not created during operations and were not included in the archive release 0040 due to an issue with the EK generation. This issue caused them to not be generated regularly as planned and instead to have all their data be accumulated and written to the EK file lroevnt_2019269_2019276_v01.bes when the issue was resolved. This EK file was added to the archive in the release 0041 with its original name in which the start and stop date tokens do not correctly reflect the coverage span of the data -- the actual data span is DOY 223 to 276 rather than DOY 269 to 276. 16. Gaps due to processor reset ----------------------------------------------------- The following irrecoverable gap in the Solar Array (SA), High Gain Antenna (HGA), and Spacecraft (SC) CK files are due to a planned processor reset: Gap start time, UTC Gap stop time, UTC Duration, sec ------------------------- ------------------------- ------------- 2019-12-19T15:41:23.00000 2019-12-19T17:42:11.00000 7248.000002 The following irrecoverable gap in the Solar Array (SA), High Gain Antenna (HGA), and Spacecraft (SC) CK files are due to an autonomous processor reset: Gap start time, UTC Gap stop time, UTC Duration, sec ------------------------- ------------------------- ------------- 2021-11-16T09:01:34.00000 2021-11-16T09:02:00.00000 26.000000 17. Gaps due to problems at WS1 Ground Station ----------------------------------------------------- The following irrecoverable gap in the Solar Array (SA), High Gain Antenna (HGA), and Spacecraft (SC) CK files is due to snow and ice from a winter storm on the WS1 antenna preventing any Ka-Band data downlinks on 2022-134 for the first three out of four passes. To prevent the recorder from filling onboard the spacecraft, seven Spacecraft HK files were deleted. Gap start time, UTC Gap stop time, UTC Duration, sec ------------------------- ------------------------- ------------- 2022-02-02T23:09:02.00000 2022-02-02T12:49:10.00000 49208.000000 18. Gaps due to problems at WS1 Ground Station ----------------------------------------------------- The following irrecoverable gap in the Solar Array (SA), High Gain Antenna (HGA), and Spacecraft (SC) CK files is due to the WS1 ground station going red and causing LRO to miss an entire block of Ka-Band downlinks. To prevent the recorder from filling onboard the spacecraft, eight Spacecraft HK files were deleted. Gap start time, UTC Gap stop time, UTC Duration, sec ------------------------- ------------------------- ------------- 2023-02-26T03:28:12.78254 2023-02-26T19:03:27.98320 56115.200664 2023-02-27T17:09:41.98330 2023-02-27T17:14:46.78329 304.799990 End of errata.txt