JUNO Nominal Orientation CK File -- 14-day Orbit Option ============================================================= Created on July 17, 2014 by Boris Semenov, NAIF/JPL. Summary ------------------------------------------------------------- This CK contains the "14-day Orbit Option" orientation of the JUNO spacecraft frame (JUNO_SPACECRAFT) based on the spin axis pointing and rotation timelines for the 14-day orbit option from the Stuart Stephens' specification e-mail "Juno C-kernels for trajectory options with 14- and 20-day orbits" from 07/16/14. Implementation Notes ------------------------------------------------------------- The JUNO_SPACECRAFT orientation is provided in this file using a combination of two kinds of segments: - segments providing the orientation of the JUNO spin axis (+Z) encapsulated in the orientation of the JUNO_SPIN_AXIS frame (frame ID -61900) relative to the J2000 inertial frame. These segments were generated using SPICE utility program "prediCkt" based on the spin axis pointing profile from the source e-mail. See Appendix 1 below for more details about these segments ("prediCkt" inputs, fit accuracy, etc.) - segments providing the rotation of the spacecraft about the spin axis encapsulated in the orientation of the JUNO_SPACECRAFT frame (frame ID -61000) relative to the JUNO_SPIN_AXIS frame. These segments were generated using SPICE utility program "msopck" based on the rotation profile from the source e-mail. See Appendix 2 below for details about these segments ("msopck" setup parameters, input, etc.). The segments generated by "prediCkt" and "msopck" were merged together into a single file (this file) using SPICE utility "dafcat". After merging the file was augmented with these comments. Modeling Notes ------------------------------------------------------------- Users of this CK file should be aware that: - the time-lines in the source spreadsheet ignored Main Engine maneuvers, for which the pointing and spin rate - the time-lines in the source spreadsheet did not include Earth-repointing precessions - the spin axis pointing (+Z of the JUNO_SPIN_AXIS frame) was modeled to be within 0.25 degrees of JUNO-Earth, or JUNO-Anti Orbital Momentum Vector (depending of the attitude mode). The ZX plane of the JUNO_SPIN_AXIS frame was modeled to always contain Ecliptic North, with the +X axis to be as close to it as possible. - five minute windows were used for continuous transitions between the spin axis pointing modes. Coverage ------------------------------------------------------------- This file provides the continuous coverage for the following period: Begin UTC End UTC ------------------------ ------------------------ 2016-04-06T02:47:16.996 2018-03-06T10:00:54.998 Related Kernels ------------------------------------------------------------- This was generated with and must be used together with the following kernels: Type Name ---- ------------------------------------------ LSK naif0010.tls SCLK JNO_SCLKSCET.00027.tsc FK juno_v02.tf (or later version) SPK 53_5d_14d_PJ38_impact.bsp Contact Information ------------------------------------------------------------- Contact Boris Semenov (Boris.Semenov@jpl.nasa.gov) if you have any questions regarding this file. Appendix 1: Information for Spin Axis Orientation Segments ============================================================= This C-kernels was produced using the SPICE program "prediCkt" on 2014-JUL-17 10:21:06. The following files were provided in support of the construction of the attitude given in this kernel. File Type Name ---- ------------------------------------------ SPK jup230.bsp SPK 53_5d_14d_PJ38_impact.bsp TEXT naif0010.tls This C-kernel matches the specification given below to 0.25000 degrees. The text kernel used to specify the orientation of structures included in this file is given below. ============================================================= Spin Axis Orientation -- 14-day orbit Scenario ----------------------------------------------------------------- These segments contain the orientation data for the JUNO_SPIN_AXIS frame (frame ID -61900) relative to the J2000 inertial frame according to 14-day orbit option from the Stuart Stephens' specification e-mail "Juno C-kernels for trajectory options with 14- and 20-day orbits" from 07/16/14. These segments were generated using PREDICKT with the direction, orientation and schedule specifications provided below. NOTE: the 14-day orbit option is implemented by the SPK 53_5d_14d_PJ38_impact.bsp and has JOI on 7/5/16, 2 x 53.5-day capture orbits, Period Reduction Maneuver on 10/19/16, 32 x 14-day science orbits, plus a few extra orbits, then Jupiter impact at PJ38 on 3/6/18. Directions ----------------------------------------------------------------- TOSUN is the geometric position of the Sun relative to JUNO. TOEARTH is the geometric position of the Earth relative to JUNO. JUNOPOS is the geometric position of JUNO relative to Jupiter. JUNOVEL is the geometric velocity of JUNO relative to Jupiter. JUNOORB is the JUNO orbital momentum vector computed as the cross product of the JUNO position and velocity relative to Jupiter. JUNOORB14 is the JUNO orbital momentum vector rotated by -14 degrees about JUNOPOS. ECLIPN is the +Z axis (North pole) of the Ecliptic of J2000 inertial frame (ECLIPJ2000). \begindata DIRECTION_SPECS += ( 'TOSUN = POSITION OF SUN -' ) DIRECTION_SPECS += ( 'FROM JUNO -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'TOEARTH = POSITION OF EARTH -' ) DIRECTION_SPECS += ( 'FROM JUNO -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'JUNOPOS = POSITION OF JUNO -' ) DIRECTION_SPECS += ( 'FROM JUPITER -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'JUNOVEL = VELOCITY OF JUNO -' ) DIRECTION_SPECS += ( 'FROM JUPITER -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'JUNOORB = CROSS PRODUCT -' ) DIRECTION_SPECS += ( 'JUNOPOS JUNOVEL ' ) DIRECTION_SPECS += ( 'JUNOORB14 = ROTATE JUNOORB -' ) DIRECTION_SPECS += ( '-14 DEGREES -' ) DIRECTION_SPECS += ( 'ABOUT JUNOPOS ' ) DIRECTION_SPECS += ( 'ECLIPN = FIXED ECLIPJ2000 -' ) DIRECTION_SPECS += ( 'XYZ 0 0 1' ) \begintext Orientations ----------------------------------------------------------------- SUN_POINTED orientation has +Z along direction from JUNO to the Sun and Ecliptic North pole defining the ZX plane. EARTH_POINTED orientation has +Z along direction from JUNO to the Earth and Ecliptic North pole defining the ZX plane. MWR_ATTITUDE orientation has -Z along JUNO orbital momentum vector (POS cross VEL) and Ecliptic North pole defining the ZX plane. MWR_ATTITUDE_TILT14 orientation has -Z along JUNO orbital momentum vector (POS cross VEL) rotated by -14 degrees about POS and Ecliptic North pole defining the ZX plane. \begindata ORIENTATION_NAME += 'SUN_POINTED' PRIMARY += '+Z = TOSUN' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'EARTH_POINTED' PRIMARY += '+Z = TOEARTH' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWR_ATTITUDE' PRIMARY += '-Z = JUNOORB' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWR_ATTITUDE_TILT14' PRIMARY += '-Z = JUNOORB14' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' \begintext Schedule ----------------------------------------------------------------- Schedule is based on the following time-line from Stuart Stephens' e-mail: +Z-axis pointing direction Start End -------------------------- ------- ------- Earth JOI-90d PJ4-14h MWR attitude (PJ4) PJ4-14h PJ4+3h Earth PJ4+3h PJ6-14h MWR attitude (PJ6) PJ6-14h PJ6+3h Earth PJ6+3h AJ6+10h MWR attitude (cal) AJ6+10h AJ6+20h Earth AJ6+20h PJ7-14h MWR attitude (PJ7) PJ7-14h PJ7+3h Earth PJ7+3h PJ8-14h MWR attitude (PJ8) PJ8-14h PJ8+3h Earth PJ8+3h PJ9-14h Tilted MWR attitude (PJ9) PJ9-14h PJ9+3h Earth PJ9+3h EOM where: * JOI = 07/05/16 02:47:17 UTC * PJ4 = 11/16/16 17:09:19 UTC * PJ6 = 12/14/16 15:04:32 UTC * AJ6 = 12/21/16 14:31:41 UTC * PJ7 = 12/28/16 14:02:09 UTC * PJ8 = 01/11/17 14:14:11 UTC * PJ9 = 01/25/17 13:11:46 UTC * EOM = 03/06/18 10:00:55 UTC In this scenario MWR attitudes are modeled as the MWR_ATTITUDE_TILT14 orientation frozen at the times of the corresponding equator crossings that for the reference SPK are: Node UTC Note ----- ----------------- ------------------------------------ EqX9 01/25/17 13:16:05 Post-PJ9 descending equator crossing These times are given as ETs by the 'AT' modifiers in the schedule assignments below. Five minute gaps were inserted at the attitude mode boundaries to ensure smooth transitions. Times is the keywords below are ETs. \begindata CK-SCLK = 61 CK-SPK = -61 CK-FRAMES = -61900 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-04-06/02:48:24.182 CK-61900STOP += @2016-11-16/03:07:56.184 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-11-16/03:12:56.184 CK-61900STOP += @2016-11-16/20:07:56.184 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-11-16/20:12:56.184 CK-61900STOP += @2016-12-14/01:03:09.184 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-12-14/01:08:09.184 CK-61900STOP += @2016-12-14/18:03:09.184 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-12-14/18:08:09.184 CK-61900STOP += @2016-12-22/00:30:18.184 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-12-22/00:35:18.184 CK-61900STOP += @2016-12-22/10:30:18.184 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-12-22/10:35:18.184 CK-61900STOP += @2016-12-28/00:00:46.184 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-12-28/00:05:46.184 CK-61900STOP += @2016-12-28/17:00:46.184 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-12-28/17:05:46.184 CK-61900STOP += @2017-01-11/00:12:48.184 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2017-01-11/00:17:48.184 CK-61900STOP += @2017-01-11/17:12:48.184 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2017-01-11/17:17:48.184 CK-61900STOP += @2017-01-24/23:10:23.184 CK-61900ORIENTATION += 'MWR_ATTITUDE_TILT14 AT 2017-01-25/13:17:12.184' CK-61900START += @2017-01-24/23:15:23.184 CK-61900STOP += @2017-01-25/16:10:23.184 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2017-01-25/16:15:23.184 CK-61900STOP += @2018-03-06/10:02:02.184 \begintext Appendix 2: Information for Rotation About Spin Axis Segment ============================================================= ******************************************************************************** MSOPCK SETUP FILE: juno_sc_nom_160406_180306_14d_v01_spin.setup ******************************************************************************** Spin Orientation ----------------------------------------------------------------- This segment contains the orientation data representing rotating of the JUNO_SPACECRAFT frame (frame ID -61000) about the JUNO_SPIN_AXIS frame (frame ID -61900) according to the 14-day orbit option profile provided in Stuart Stephens' specification e-mail "Juno C-kernels for trajectory options with 14- and 20-day orbits" from 07/16/14: Spin Rate Start End Note --------- ------- ------- ---------------------------- 2 rpm JOI-90d EOM Pre-insertion and orbital ops where * JOI = 07/05/16 02:47:17 UTC * EOM = 03/06/18 10:00:55 UTC The profile above was converted to the following input provided to MSOPCK to make this segment (the columns are: start UTC, stop UTC, initial orientation as three angles set to zero, and angular velocity representing CCW rotation about +Z): 2016-04-06/02:48:24.182TDB 2018-03-06/10:02:02.184TDB 0 0 0 0 0 0.20943951023932 The following MSOPCK setup parameters were used to generate this segment: \begindata LSK_FILE_NAME = 'naif0010.tls' SCLK_FILE_NAME = 'JNO_SCLKSCET.00027.tsc' FRAMES_FILE_NAME = 'juno_v02.tf' INTERNAL_FILE_NAME = 'JUNO NOMINAL SPIN ATTITUDE, 14-day' CK_TYPE = 2 CK_SEGMENT_ID = 'JUNO NOMINAL SPIN ATTITUDE, 14-day' INSTRUMENT_ID = -61000 REFERENCE_FRAME_NAME = 'JUNO_SPIN_AXIS' ANGULAR_RATE_PRESENT = 'YES' INPUT_TIME_TYPE = 'UTC' INPUT_DATA_TYPE = 'EULER ANGLES' EULER_ANGLE_UNITS = 'RADIANS' EULER_ROTATIONS_ORDER = ( 'X' 'Y' 'Z' ) ANGULAR_RATE_FRAME = 'INSTRUMENT' PRODUCER_ID = 'NAIF/JPL' \begintext ******************************************************************************** RUN-TIME OBTAINED META INFORMATION: ******************************************************************************** PRODUCT_CREATION_TIME = 2014-07-17T10:19:37 START_TIME = 2016-04-06T02:47:16.996 STOP_TIME = 2018-03-06T10:00:54.998 ******************************************************************************** INTERPOLATION INTERVALS IN THE FILE SEGMENTS: ******************************************************************************** SEG.SUMMARY: ID -61000, COVERG: 2016-04-06T02:47:16.996 2018-03-06T10:00:54.998 -------------------------------------------------------------------------------- 2016-04-06T02:47:16.996 2018-03-06T10:00:54.998 ******************************************************************************** Appendix 3: Contents of specification e-mail ============================================================= Below is the Stuart Stephens' specification e-mail "Juno C-kernels for trajectory options with 14- and 20-day orbits" from 07/16/14: Subject: Juno C-kernels for trajectory options with 14- and 20-day orbits Date: Wed, 16 Jul 2014 17:32:10 +0000 From: Stephens, Stuart K (394A) To: Semenov, Boris V (392N) CC: Hirst, Edward A (4400) , Johnson, Matthew B (3940) Hi Boris, Thanks for agreeing to generate C-kernels for Juno's alternate science orbit trajectory options that we're currently considering. This is part of an ongoing trade in which we're requesting feedback from our instrument teams ~ who are asking for attitude information for these alternate trajectories. If you can provide C-kernels this week, that would be ideal, since it gives the instrument folks time to evaluate them before an 8/13 meeting at which we've requested their feedback. But it's still useful as late as the first week in August. The input information is similar to what went into your 2/7/2012 C-kernels, and the output products should also be similar. They're still at this location: http://naif.jpl.nasa.gov/pub/naif/JUNO/misc/nomck/ We asked you to do 3 cases for 1 spacecraft trajectory in 2012, but now we're requesting 1 case for 2 trajectory options. The trajectories are attached (both begin about 5 months before JOI on 2/3/16): * 53_5d_14d_PJ38_impact.bsp = JOI on 7/5/16, 2 x 53.5-day capture orbits, Period Reduction Maneuver on 10/19/16, 32 x 14-day science orbits, plus a few extra orbits, then Jupiter impact at PJ38 on 3/6/18. * 53_5d_20d_PJ38_impact.bsp = JOI on 7/5/16, 2 x 53.5-day capture orbits, Period Reduction Maneuver on 10/19/16, 32 x 20-day science orbits, plus a few extra orbits, then Jupiter impact at PJ38 on 10/7/18. * (For your reference, our current baseline trajectory has the same JOI and PRM dates, but 1 x 107-day capture orbit, 30 x 11-day science orbits, and impact on 10/16/17. This was what you provided C-kernels for in 2012.) If you need additional kernels, let me know ~ there are some specified in the .cmt files at the naif URL above, so you can use those or more recent versions. For both trajectories, please use this sequence of attitudes for the C-kernels: +Z-axis pointing direction Start End -------------------------- ------- ------- Earth JOI-90d PJ4-14h MWR attitude (PJ4) PJ4-14h PJ4+3h Earth PJ4+3h PJ6-14h MWR attitude (PJ6) PJ6-14h PJ6+3h Earth PJ6+3h AJ6+10h MWR attitude (cal) AJ6+10h AJ6+20h Earth AJ6+20h PJ7-14h MWR attitude (PJ7) PJ7-14h PJ7+3h Earth PJ7+3h PJ8-14h MWR attitude (PJ8) PJ8-14h PJ8+3h Earth PJ8+3h PJ9-14h Tilted MWR attitude (PJ9) PJ9-14h PJ9+3h Earth PJ9+3h EOM But the times associated with these epochs is different for the 2 trajectories. For the 14-day orbits: * JOI = 07/05/16 02:47:17 UTC * PJ4 = 11/16/16 17:09:19 UTC * PJ6 = 12/14/16 15:04:32 UTC * AJ6 = 12/21/16 14:31:41 UTC * PJ7 = 12/28/16 14:02:09 UTC * PJ8 = 01/11/17 14:14:11 UTC * PJ9 = 01/25/17 13:11:46 UTC * EqX9 = 01/25/17 13:16:05 UTC (post-PJ9 descending equator crossing) * EOM = 03/06/18 10:00:55 UTC And for the 20-day orbits: * JOI = 07/05/16 02:47:17 UTC * PJ4 = 11/28/16 16:47:01 UTC * PJ6 = 01/07/17 14:31:33 UTC * AJ6 = 01/17/17 13:57:43 UTC * PJ7 = 01/27/17 13:23:48 UTC * PJ8 = 02/16/17 11:01:39 UTC * PJ9 = 03/08/17 09:53:58 UTC * EqX9 = 03/08/17 09:58:18 UTC (post-PJ9 descending equator crossing) * EOM = 10/07/18 23:01:16 UTC Please note orbit numbers are incremented by 1 with respect to the numbers for the current 11-day orbits, due to adding a 2nd capture orbit. Also note: * Spin rate = 2 RPM from JOI-90d to EOM. Initial spin phase is unimportant. * We're ignoring spin rate and attitude changes for Main Engine maneuvers. * We're ignoring Earth-point precessions (always Earth-pointed instead). * The AJ6 orientation is for a planned MWR apojove cal at an MWR attitude. * The earlier .cmt files provide a guide for how to orient coordinate frames, 5-minute windows for continuous transitions between pointing modes, etc. * Earth pointing = +Z-to-Earth. * MWR attitude = ~Z-to-orbit normal direction (i.e., momentum vector). * Tilted MWR attitude = ~Z-to-momentum vector rotated by ~14 deg about the geometric position of Juno with respect to Jupiter at the descending equator crossing following PJ9 (see attitudes for 3rd "tilt" case from 2012). The main output products we need are the C-kernels, and perhaps comment files. Also, if it's easy for you to generate angle plots (.png files) like you did in 2012, that will help us to quickly check that the attitudes make sense. Let me know if I've forgotten to provide any additional information you need, or if you have questions. Thanks! -- Stuart, x3-7807 End of comments.