KPL/SCLK FILENAME = "europaclipper_00227.tsc" CREATION_DATE = "12-Feb-2026" Europa Clipper Spacecraft Clock Kernel (SCLK) ================================================================= This file is a SPICE spacecraft clock (SCLK) kernel containing information required for time conversions involving the on-board Europa Clipper spacecraft clock ('SCLK'). Version -------------------------------------------------------- Version History of Europa Clipper Seed Kernel: Version 1.0 -- July 05, 2018 -- Stan Cooper Initial (seed) time coefficients triplet set for SCLK = 0 at 2010-001-00:00:00 UTC for Europa Clipper. Note that this was set using the value of 34 leap seconds. Note also that this is the SCLK = 0 UTC epoch expected to be used for Observatory SI&T as well as for Europa Clipper launch. The sub-seconds is set to a maximum of 65,536 ticks in the "SCLK01_MODULI_159" parameter. That was chosen for this SCLK kernel because all downlink packet secondary headers will include a 16-bit sub-seconds field with least significant bit resolution of 2^-16 second, so a tick is assumed to represent an interval of 2^-16 second. The end of the first partition is currently defined as the value in ticks of the maximum value of the spacecraft clock. Usage -------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of this SCLK kernel must 'load' the kernel, normally during program initialization. Loading the kernel associates the data items with their names in a data structure called the 'kernel pool'. The SPICELIB routine FURNSH loads text kernel files, such as this one, into the pool as shown below: FORTRAN: CALL FURNSH ( SCLK_kernel_name ) C: furnsh_c ( SCLK_kernel_name ); Once loaded, the SCLK time conversion routines will be able to access the necessary data located in this kernel for their designed purposes. References -------------------------------------------------------- 1. "SCLK Required Reading" Inquiries -------------------------------------------------------- If you have any questions regarding this file or its usage, contact: Robert Seng (240) 228-3607 Robert.Seng@jhuapl.edu Kernel Data -------------------------------------------------------- The Europa Clipper spacecraft clock is represented by the SPICE type 1 SCLK kernel. It uses TDT, Terrestrial Dynamical Time, as its parallel time system. \begindata SCLK_KERNEL_ID = ( @2018-07-05T20:00:00 ) SCLK_DATA_TYPE_159 = ( 1 ) SCLK01_TIME_SYSTEM_159 = ( 2 ) \begintext In a particular partition of the Europa Clipper spacecraft clock, the clock read-out consists of two separate stages: 1/18424652:24251 The first stage, an unsigned 32 bit field, represents the spacecraft clock seconds count. The second, an unsigned 16 bit field, represents counts of 2^-16 second increments of the spacecraft clock. The following keywords and their values establish this structure: \begindata SCLK01_N_FIELDS_159 = ( 2 ) SCLK01_MODULI_159 = ( 4294967296 65536 ) SCLK01_OFFSETS_159 = ( 0 0 ) SCLK01_OUTPUT_DELIM_159 = ( 2 ) \begintext This concludes the invariant portion of the SCLK kernel data. The remaining sections of the kernel may require updates as the clock correlation coefficients evolve in time. The first section below establishes the clock partitions. The data in this section consists of two parallel arrays, which denote the start and end values in ticks of each partition of the spacecraft clock. SPICE utilizes these two arrays to map from spacecraft clock ticks, determined with the usual modulo arithmetic, to encoded SCLK--the internal, monotonically increasing sequence used to tag various data sources with spacecraft clock. \begindata SCLK_PARTITION_START_159 = ( 0.00000000000000e+00 ) SCLK_PARTITION_END_159 = ( 2.81474976710655e+14 ) \begintext The remaining section of the SCLK kernel defines the clock correlation coefficients. Each line contains a 'coefficient triple': Encoded SCLK at which Rate is introduced. Corresponding TDT Epoch at which Rate is introduced. Rate in TDT (seconds) / most significant clock count (~seconds). SPICE uses linear extrapolation to convert between the parallel time scale (TDT) and encoded SCLK. The triples are stored in the array defined below. The first time triplet below was entered manually and represents the approximate time (in TDT) at which SCLK = zero. Note that the conversion from UTC to TDT used 34 leap seconds. The second and third time triplets were also entered manually. The third triplet represent the first data point with an actual clock rate anchored near the launch vehicle separation time (2024-10-14 17:08:33 UTC). The second triplet is an artificial point anchored 100 SCLK coarse ticks (seconds) before the separation time with the rate ensuring continuity from the pre-launch nominal trend to the first actual data point.  \begindata SCLK01_COEFFICIENTS_159 = ( 0 @01-JAN-2010-00:01:06.184000 1.00000000000 30580514357248 @14-OCT-2024-17:08:04.184000 0.97708417060 30580520910848 @14-OCT-2024-17:09:41.892417 1.00000003725 30615501668352 @20-OCT-2024-21:25:45.912286 1.00000003766 30626568470528 @22-OCT-2024-20:20:11.918645 1.00000003726 30791209582592 @20-NOV-2024-22:10:36.012242 1.00000003770 30870740729856 @04-DEC-2024-23:16:25.057988 1.00000003768 30948583079936 @18-DEC-2024-17:12:45.102748 1.00000003732 31157026226176 @24-JAN-2025-12:42:35.221435 1.00000003650 31169864073216 @26-JAN-2025-19:07:25.228585 1.00000003648 31203423223808 @01-FEB-2025-17:21:57.247265 1.00000003651 31221018525696 @04-FEB-2025-19:56:40.257068 1.00000003650 31243194531840 @08-FEB-2025-17:56:19.269418 1.00000003665 31260750512128 @11-FEB-2025-20:21:02.279236 1.00000003654 31290652557312 @17-FEB-2025-03:05:31.295907 1.00000003653 31303273938944 @19-FEB-2025-08:35:18.302942 1.00000003669 31321321242624 @22-FEB-2025-13:04:58.313047 1.00000003669 31344794468352 @26-FEB-2025-16:34:31.326190 1.00000003704 31373044940800 @03-MAR-2025-16:18:59.342157 1.00000003668 31388379054080 @06-MAR-2025-09:18:39.350740 1.00000003649 31403831132160 @09-MAR-2025-02:48:19.359344 1.00000003648 31427913646080 @13-MAR-2025-08:52:49.372750 1.00000003652 31440927981568 @15-MAR-2025-16:02:32.380002 1.00000003649 31460449452032 @19-MAR-2025-02:47:06.390871 1.00000003674 31480560680960 @22-MAR-2025-16:01:39.402144 1.00000003720 31495481917440 @25-MAR-2025-07:16:19.410614 1.00000003715 31512644288512 @28-MAR-2025-08:00:56.420343 1.00000003646 31546556088320 @03-APR-2025-07:45:09.439209 1.00000003659 31559550566400 @05-APR-2025-14:49:49.446464 1.00000003659 31574884548608 @08-APR-2025-07:49:27.455025 1.00000003678 31594150363136 @11-APR-2025-17:29:00.465837 1.00000003686 31618153971712 @15-APR-2025-23:13:26.479337 1.00000003686 31637242970112 @19-APR-2025-08:08:01.490074 1.00000003702 31663094431744 @23-APR-2025-21:42:23.504677 1.00000003707 31680099450880 @26-APR-2025-21:46:59.514296 1.00000003722 31696671932416 @29-APR-2025-20:01:35.523709 1.00000003732 31712753025024 @02-MAY-2025-16:11:13.532867 1.00000003806 31787189207040 @15-MAY-2025-19:41:19.576094 1.00000003845 31792811671552 @16-MAY-2025-19:31:11.579393 1.00000003795 31795485212672 @17-MAY-2025-06:51:06.580941 1.00000003828 31810603057152 @19-MAY-2025-22:55:46.589772 1.00000003839 31816343552000 @20-MAY-2025-23:15:39.593134 1.00000003833 31833250332672 @23-MAY-2025-22:55:16.603021 1.00000003851 31841743011840 @25-MAY-2025-10:55:04.608011 1.00000003847 31850255351808 @26-MAY-2025-22:59:52.613008 1.00000003864 31856566009856 @28-MAY-2025-01:44:45.616729 1.00000003852 31867201519616 @29-MAY-2025-22:49:30.622980 1.00000003856 31872391512064 @30-MAY-2025-20:49:23.626034 1.00000003848 31883203969024 @01-JUN-2025-18:39:08.632382 1.00000003876 31889809473536 @02-JUN-2025-22:39:00.636289 1.00000003863 31895451664384 @03-JUN-2025-22:33:53.639615 1.00000003859 31906755641344 @05-JUN-2025-22:28:38.646271 1.00000003958 31907679567872 @06-JUN-2025-02:23:36.646829 1.00000003869 31923721535488 @08-JUN-2025-22:23:17.656300 1.00000003887 31940392452096 @11-JUN-2025-21:02:55.666188 1.00000003876 31951932424192 @13-JUN-2025-21:57:41.673013 1.00000003885 31969507737600 @17-JUN-2025-00:27:19.683432 1.00000003898 31975464501248 @18-JUN-2025-01:42:12.686975 1.00000003877 31985844551680 @19-JUN-2025-21:41:59.693115 1.00000003886 31986650578944 @20-JUN-2025-01:06:58.693593 1.00000003901 31997168320512 @21-JUN-2025-21:41:46.699854 1.00000003896 32014134280192 @24-JUN-2025-21:36:26.709941 1.00000003912 32017613979648 @25-JUN-2025-12:21:22.712018 1.00000003921 32025418596352 @26-JUN-2025-21:26:11.716687 1.00000003911 32036722769920 @28-JUN-2025-21:20:59.723433 1.00000003908 32047613935616 @30-JUN-2025-19:30:45.729928 1.00000003920 32054140928000 @01-JUL-2025-23:10:39.733832 1.00000003917 32064933986304 @03-JUL-2025-20:55:28.740283 1.00000003984 32065700626432 @04-JUL-2025-00:10:26.740749 1.00000003932 32074586718208 @05-JUL-2025-13:50:17.746080 1.00000003926 32080975953920 @06-JUL-2025-16:55:09.749908 1.00000003951 32087502946304 @07-JUL-2025-20:35:03.753843 1.00000003924 32093243506688 @08-JUL-2025-20:54:57.757280 1.00000003937 32094993121280 @09-JUL-2025-04:19:54.758331 1.00000003955 32104154464256 @10-JUL-2025-19:09:45.763860 1.00000003945 32109934346240 @11-JUL-2025-19:39:39.767339 1.00000003944 32111094267904 @12-JUL-2025-00:34:38.768037 1.00000003952 32120943607808 @13-JUL-2025-18:19:27.773977 1.00000003969 32127136497664 @14-JUL-2025-20:34:23.777728 1.00000003959 32143886385152 @17-JUL-2025-19:34:06.787846 1.00000003945 32149744910336 @18-JUL-2025-20:24:00.791373 1.00000003974 32161049214976 @20-JUL-2025-20:18:50.798227 1.00000003973 32172314066944 @22-JUL-2025-20:03:38.805056 1.00000003972 32175361425408 @23-JUL-2025-08:58:37.806903 1.00000003981 32179155632128 @24-JUL-2025-01:03:32.809208 1.00000003989 32189300080640 @25-JUL-2025-20:03:24.815383 1.00000003997 32200014495744 @27-JUL-2025-17:28:13.821918 1.00000003997 32206246641664 @28-JUL-2025-19:53:08.825719 1.00000003978 32211594117120 @29-JUL-2025-18:33:04.828965 1.00000003994 32227833020416 @01-AUG-2025-15:22:50.838862 1.00000004004 32234399399936 @02-AUG-2025-19:12:45.842874 1.00000004005 32239628779520 @03-AUG-2025-17:22:39.846070 1.00000004001 32245566210048 @04-AUG-2025-18:32:37.849695 1.00000004003 32262611271680 @07-AUG-2025-18:47:24.860107 1.00000004024 32268351897600 @08-AUG-2025-19:07:19.863632 1.00000003988 32278968270848 @10-AUG-2025-16:07:12.870092 1.00000003959 32286851792896 @12-AUG-2025-01:32:05.874854 1.00000003969 32302206353408 @14-AUG-2025-18:36:57.884152 1.00000004037 32307868336128 @15-AUG-2025-18:36:52.887639 1.00000004017 32318268375040 @17-AUG-2025-14:41:44.894013 1.00000004041 32327567605760 @19-AUG-2025-06:06:39.899747 1.00000004032 32331696177152 @19-AUG-2025-23:36:36.902287 1.00000004046 32341860483072 @21-AUG-2025-18:41:31.908562 1.00000004037 32350235656192 @23-AUG-2025-06:11:26.913721 1.00000004043 32359928037376 @24-AUG-2025-23:16:20.919700 1.00000004038 32363899322368 @25-AUG-2025-16:06:17.922147 1.00000004056 32370623119360 @26-AUG-2025-20:36:14.926308 1.00000004059 32388769447936 @30-AUG-2025-01:31:05.937547 1.00000004066 32394490675200 @31-AUG-2025-01:46:04.941097 1.00000004056 32405048066048 @01-SEP-2025-22:30:57.947631 1.00000004061 32411359051776 @03-SEP-2025-01:15:55.951542 1.00000004074 32420697735168 @04-SEP-2025-16:50:52.957347 1.00000004074 32427362484224 @05-SEP-2025-21:05:48.961490 1.00000004075 32437192687616 @07-SEP-2025-14:45:45.967602 1.00000004097 32442147012608 @08-SEP-2025-11:45:42.970699 1.00000004085 32456656355328 @11-SEP-2025-01:15:37.979744 1.00000004079 32466093342720 @12-SEP-2025-17:15:34.985617 1.00000004081 32471598366720 @13-SEP-2025-16:35:34.989045 1.00000004088 32477476749312 @14-SEP-2025-17:30:31.992712 1.00000004086 32483040755712 @15-SEP-2025-17:05:31.996181 1.00000004106 32488781578240 @16-SEP-2025-17:25:29.999778 1.00000004095 32499870138368 @18-SEP-2025-16:25:28.006707 1.00000004113 32506652917760 @19-SEP-2025-21:10:25.010964 1.00000004102 32512393871360 @20-SEP-2025-21:30:25.014557 1.00000004100 32522971185152 @22-SEP-2025-18:20:22.021175 1.00000004094 32527217917952 @23-SEP-2025-12:20:22.023828 1.00000004106 32533843542016 @24-SEP-2025-16:25:21.027979 1.00000004120 32546819538944 @26-SEP-2025-23:25:19.036136 1.00000004107 32550928646144 @27-SEP-2025-16:50:19.038711 1.00000004117 32564868087808 @30-SEP-2025-03:55:18.047467 1.00000004130 32588893454336 @04-OCT-2025-09:45:16.062606 1.00000004128 32600395087872 @06-OCT-2025-10:30:17.069850 1.00000004134 32607846531072 @07-OCT-2025-18:05:17.074550 1.00000004147 32614885097472 @08-OCT-2025-23:55:17.079004 1.00000004138 32625993515008 @10-OCT-2025-23:00:18.086018 1.00000004148 32634998226944 @12-OCT-2025-13:10:19.091717 1.00000004162 32659358154752 @16-OCT-2025-20:25:22.107188 1.00000004162 32670997479424 @18-OCT-2025-21:45:24.114580 1.00000004161 32674654519296 @19-OCT-2025-13:15:26.116902 1.00000004162 32683344658432 @21-OCT-2025-02:05:27.122421 1.00000004178 32698090455040 @23-OCT-2025-16:35:30.131821 1.00000004174 32706190835712 @25-OCT-2025-02:55:32.136980 1.00000004193 32715647877120 @26-OCT-2025-19:00:35.143030 1.00000004188 32727680614400 @28-OCT-2025-22:00:40.150719 1.00000004195 32738867806208 @30-OCT-2025-21:25:43.157880 1.00000004185 32744097775616 @31-OCT-2025-19:35:46.161220 1.00000004206 32753751425024 @02-NOV-2025-12:30:49.167416 1.00000004175 32761242386432 @03-NOV-2025-20:15:52.172188 1.00000004200 32778328080384 @06-NOV-2025-20:40:59.183137 1.00000004208 32783145238528 @07-NOV-2025-17:06:03.186230 1.00000004208 32802354298880 @11-NOV-2025-02:31:10.198565 1.00000004210 32817415061504 @13-NOV-2025-18:21:19.208241 1.00000004226 32834618916864 @16-NOV-2025-19:16:29.219334 1.00000004238 32841913270272 @18-NOV-2025-02:11:32.224051 1.00000004233 32863324864512 @21-NOV-2025-20:56:47.237880 1.00000004242 32873706160128 @23-NOV-2025-16:56:53.244599 1.00000004247 32880155164672 @24-NOV-2025-20:16:57.248777 1.00000004251 32902019088384 @28-NOV-2025-16:57:14.262958 1.00000004257 32911122497536 @30-NOV-2025-07:32:21.268871 1.00000004264 32919793303552 @01-DEC-2025-20:17:27.274513 1.00000004256 32924276162560 @02-DEC-2025-15:17:30.277424 1.00000004268 32945904353280 @06-DEC-2025-10:57:50.291508 1.00000004267 32954535903232 @07-DEC-2025-23:32:57.297128 1.00000004268 32959392382976 @08-DEC-2025-20:08:01.300291 1.00000004275 32969931161600 @10-DEC-2025-16:48:10.307165 1.00000004282 32985247842304 @13-DEC-2025-09:43:24.317172 1.00000004286 32992829505536 @14-DEC-2025-17:51:31.322130 1.00000004294 32999404470272 @15-DEC-2025-21:43:37.326438 1.00000004290 33010395578368 @17-DEC-2025-20:18:48.333632 1.00000004286 33016058216448 @18-DEC-2025-20:18:53.337335 1.00000004312 33024316276736 @20-DEC-2025-07:19:01.342768 1.00000004283 33030096945152 @21-DEC-2025-07:49:07.346546 1.00000004306 33038708965376 @22-DEC-2025-20:19:16.352204 1.00000004327 33043093651456 @23-DEC-2025-14:54:21.355099 1.00000004313 33061969264640 @26-DEC-2025-22:54:40.367522 1.00000004309 33069598244864 @28-DEC-2025-07:14:49.372538 1.00000004318 33077168177152 @29-DEC-2025-15:19:57.377526 1.00000004330 33089791328256 @31-DEC-2025-20:50:11.385866 1.00000004342 33095630979072 @01-JAN-2026-21:35:17.389735 1.00000004331 33107231768576 @03-JAN-2026-22:45:31.397402 1.00000004348 33117888708608 @05-JAN-2026-19:55:43.404472 1.00000004347 33123649781760 @06-JAN-2026-20:20:50.408293 1.00000004341 33127161528320 @07-JAN-2026-11:13:55.410619 1.00000004341 33134975254528 @08-JAN-2026-20:21:03.415795 1.00000004363 33140913274880 @09-JAN-2026-21:31:10.419748 1.00000004356 33157527961600 @12-JAN-2026-19:56:30.430792 1.00000004351 33162876157952 @13-JAN-2026-18:36:37.434343 1.00000004349 33168597909504 @14-JAN-2026-18:51:44.438140 1.00000004360 33174260678656 @15-JAN-2026-18:51:51.441907 1.00000004372 33179962769408 @16-JAN-2026-19:01:58.445711 1.00000004358 33196911755264 @19-JAN-2026-18:52:19.456981 1.00000004386 33202495946752 @20-JAN-2026-18:32:27.460718 1.00000004376 33208198037504 @21-JAN-2026-18:42:34.464525 1.00000004375 33214254088192 @22-JAN-2026-20:22:42.468568 1.00000004383 33229708787712 @25-JAN-2026-13:53:02.478905 1.00000004377 33236905230336 @26-JAN-2026-20:23:11.483711 1.00000004382 33242489421824 @27-JAN-2026-20:03:19.487445 1.00000004409 33247758974976 @28-JAN-2026-18:23:26.490990 1.00000004391 33253893668864 @29-JAN-2026-20:23:34.495100 1.00000004390 33258003103744 @30-JAN-2026-13:48:39.497853 1.00000004399 33265179951104 @31-JAN-2026-20:13:49.502670 1.00000004411 33267873742848 @01-FEB-2026-07:38:53.504482 1.00000004401 33276544942080 @02-FEB-2026-20:24:05.510305 1.00000004435 33281028063232 @03-FEB-2026-15:24:12.513339 1.00000004404 33293533380608 @05-FEB-2026-20:24:28.521741 1.00000004437 33302519152640 @07-FEB-2026-10:29:40.527824 1.00000004408 33309499392000 @08-FEB-2026-16:04:50.532519 1.00000004422 33314788737024 @09-FEB-2026-14:29:59.536088 1.00000004444 33320667774976 @10-FEB-2026-15:25:06.540075 1.00000004444 ) \begintext