JUNO Nominal JOI/PRM Thermal/Power Study Case CK File ============================================================= Created on December 3, 2015 by Boris Semenov, NAIF/JPL. Summary ------------------------------------------------------------- This CK contains the nominal orientation of the JUNO spacecraft frame (JUNO_SPACECRAFT) based on the JOI and PRM attitude cases provided by Stuart Stephens on 11/30/15 and 12/03/15. A description of the the specific case implemended by these segments is provided below in Appendix 1. 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 2 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 3 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 spin axis pointing (+Z of the JUNO_SPIN_AXIS frame) was modeled to be within 0.25 degrees of the ideal attitude. 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. - transitions between the spin axis pointing modes are instanteneous. Coverage ------------------------------------------------------------- See MSOPCK traceback in Appendix 3 for coverage information. Related Kernels ------------------------------------------------------------- See the list of kernels in the prediCkt trace-back in Appendix 2 and in the MSOPCK setup in Appendix 3. Contact Information ------------------------------------------------------------- Contact Boris Semenov (Boris.Semenov@jpl.nasa.gov) if you have any questions regarding this file. Appenix 1: Study Case Description ============================================= In each case, we start at Earth-point, go to 15-deg off-Sun, then go to PRM burn attitude, then return to Sun-point, before finally returning to Earth-point. All times are in UTC. Please start the C-kernels on 10/14/16 00:00 UTC, and continue through 10/30/16 00:00 UTC. The spin-up and spin-down times are shown, and spin rate changes and turns can all be modeled as instantaneous. For PRM: The 15 degrees off-Sun vector is [0.964111063995031 0.022522629667430 0.264542222405484] The PRM burn attitude vector is [0.044431713049672 -0.451429488959310 0.891199887440190] Please use the following spk to generate the ckernels: http://naif.jpl.nasa.gov/pub/naif/JUNO/kernels/spk/spk_pre_161009_161029_151020_prmPA_final.bsp Case 1) Baseline with Early Spin-up ~ used for PRM nominal and PRM one-battery analyses. CK Start: 2016-10-14T00:00:00 Pointing: Earth Start: 2016-10-15T18:00:00 Pointing: Earth 15 deg Precession: 2016-10-19T15:49:46 Change Pointing To: 15 degrees off-Sun 75 deg Precession: 2016-10-19T16:55:57 Change Pointing To: 90 degrees off-Sun Spin-up to 5 rpm 2016-10-19T17:28:55 Change spin rate from 2 to 5 rpm PRM Burn Start: 2016-10-19T18:00:00 PRM Burn Start Spin-down to 2 rpm 2016-10-19T18:24:04 Change spin rate from 5 to 2 rpm 90 deg Precession: 2016-10-19T18:37:04 Change Pointing To: Sun point Return to HGA: 2016-10-20T23:00:00 Change Pointing To: Earth CK Stop : 2016-10-28T23:00:00 Pointing: Earth Appendix 2: Information for Axis segments ============================================= This C-kernels was produced using the SPICE program "prediCkt" on 2015-DEC-09 01:03:05. The following files were provided in support of the construction of the attitude given in this kernel. File Type Name ---- ------------------------------------------ SPK jup310.bsp SPK spk_pre_161009_161029_151020_prmPA_final.bsp TEXT naif0011.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 ----------------------------------------------------------------- The spin axis Orientation segments contain the orientation data for the JUNO_SPIN_AXIS frame (frame ID -61900) relative to the J2000 inertial frame based on the JOI and PRM attitude cases provided by Stuart Stephens on 11/30/15 and 12/03/15. A description of the the specific case implemended by these segments is provided above. These segments were generated using PREDICKT with the direction, orientation, and schedule specifications provided below based on the spreadsheet data. Directions ----------------------------------------------------------------- The directions defined in this section are based on the descriptions from sheet 3 of the spreadsheet. 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). JOIOFFSUN15 is the JOI 15 degrees off-Sun vector -- [ 0.959523303658, -0.275059325035, 0.060476420600 ] in J2000. JOIOFFSUN90 is the JOI burn attitude vector is -- [ -0.012772590557035, -0.463758524048003, 0.885869568448584 ] in J2000. PRMOFFSUN15 is the PRM 15 degrees off-Sun vector -- [ 0.964111063995031, 0.022522629667430, 0.264542222405484 ] in J2000. PRMOFFSUN90 is the PRM burn attitude vector -- [ 0.044431713049672, -0.451429488959310, 0.891199887440190 ] in J2000. \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' ) DIRECTION_SPECS += ( 'JOIOFFSUN15 = FIXED J2000 XYZ -' ) DIRECTION_SPECS += ( ' 0.959523303658 -' ) DIRECTION_SPECS += ( ' -0.275059325035 -' ) DIRECTION_SPECS += ( ' 0.060476420600' ) DIRECTION_SPECS += ( 'JOIOFFSUN90 = FIXED J2000 XYZ -' ) DIRECTION_SPECS += ( ' -0.012772590557035 -' ) DIRECTION_SPECS += ( ' -0.463758524048003 -' ) DIRECTION_SPECS += ( ' 0.885869568448584' ) DIRECTION_SPECS += ( 'PRMOFFSUN15 = FIXED J2000 XYZ -' ) DIRECTION_SPECS += ( ' 0.964111063995031 -' ) DIRECTION_SPECS += ( ' 0.022522629667430 -' ) DIRECTION_SPECS += ( ' 0.264542222405484' ) DIRECTION_SPECS += ( 'PRMOFFSUN90 = FIXED J2000 XYZ -' ) DIRECTION_SPECS += ( ' 0.044431713049672 -' ) DIRECTION_SPECS += ( ' -0.451429488959310 -' ) DIRECTION_SPECS += ( ' 0.891199887440190' ) \begintext Orientations ----------------------------------------------------------------- The orientation modes defined in this section are based on the descriptions from sheet 3 of the spreadsheet. SUNPOINTED orientation has +Z along direction from JUNO to the Sun and Ecliptic North pole defining the ZX plane. EARTHPOINTED orientation has +Z along direction from JUNO to the Earth and Ecliptic North pole defining the ZX plane. MWRATTITUDE orientation has -Z along JUNO orbital momentum vector (POS cross VEL) and Ecliptic North pole defining the ZX plane. MWRATTITUDETILT14 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. JOIOFFSUN15 orientation has +Z along the reference 15-deg off-Sun direction prior the JOI burn and Ecliptic North pole defining the ZX plane. JOIOFFSUN90 orientation has +Z along the reference 90-deg off-Sun direction during the JOI burn and Ecliptic North pole defining the ZX plane. PRMOFFSUN15 orientation has +Z along the reference 15-deg off-Sun direction prior the PRM burn and Ecliptic North pole defining the ZX plane. PRMOFFSUN90 orientation has +Z along the reference 90-deg off-Sun direction during the PRM burn and Ecliptic North pole defining the ZX plane. \begindata ORIENTATION_NAME += 'SUNPOINTED' PRIMARY += '+Z = TOSUN' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'EARTHPOINTED' PRIMARY += '+Z = TOEARTH' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRATTITUDE' PRIMARY += '-Z = JUNOORB' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRATTITUDETILT14' PRIMARY += '-Z = JUNOORB14' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'JOIOFFSUN15' PRIMARY += '+Z = JOIOFFSUN15' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'JOIOFFSUN90' PRIMARY += '+Z = JOIOFFSUN90' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'PRMOFFSUN15' PRIMARY += '+Z = PRMOFFSUN15' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'PRMOFFSUN90' PRIMARY += '+Z = PRMOFFSUN90' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' \begintext Schedule ----------------------------------------------------------------- The orientation schedule defined in this section implements the spin axis pointing timeline from sheet 1 of the spreadsheet. These times in 'AT' modifiers and START/STOP keywords are given as ETs. Five minute gaps were inserted at the attitude mode boundaries to ensure smooth transitions. \begindata CK-SCLK = 61 CK-SPK = -61 CK-FRAMES = -61900 CK-61900ORIENTATION += 'EARTHPOINTED' CK-61900START += @2016-10-14-00:01:08.182 CK-61900STOP += @2016-10-19-15:50:54.182 CK-61900ORIENTATION += 'PRMOFFSUN15' CK-61900START += @2016-10-19-15:50:54.182 CK-61900STOP += @2016-10-19-16:57:05.182 CK-61900ORIENTATION += 'PRMOFFSUN90' CK-61900START += @2016-10-19-16:57:05.182 CK-61900STOP += @2016-10-19-18:38:12.182 CK-61900ORIENTATION += 'SUNPOINTED' CK-61900START += @2016-10-19-18:38:12.182 CK-61900STOP += @2016-10-20-23:01:08.182 CK-61900ORIENTATION += 'EARTHPOINTED' CK-61900START += @2016-10-20-23:01:08.182 CK-61900STOP += @2016-10-28-23:01:08.182 \begintext Appendix 3: Information for Spin segments ============================================= ******************************************************************************** MSOPCK SETUP FILE: juno_sc_nom_161014_161030_prmc1_v02.spin.setup ******************************************************************************** Spin Orientation ----------------------------------------------------------------- The spin orientation segment contains the orientation data representing rotation of the JUNO_SPACECRAFT frame (frame ID -61000) about the JUNO_SPIN_AXIS frame (frame ID -61900) based on based on the JOI and PRM attitude cases provided by Stuart Stephens on 11/30/15 and 12/03/15. A description of the specific case implemended by this segment is provided above. The input based on that descritpion and used to make this segment is shown below. The following MSOPCK setup parameters were used to generate this segment: \begindata LSK_FILE_NAME = 'naif0011.tls' SCLK_FILE_NAME = 'JNO_SCLKSCET.00035.tsc' FRAMES_FILE_NAME = 'juno_v08.tf' INTERNAL_FILE_NAME = 'JUNO NOMINAL SPIN ATTITUDE, 12/03/15' CK_TYPE = 2 CK_SEGMENT_ID = 'JUNO NOMINAL SPIN ATTITUDE, 12/03/15' 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 The following MSOPCK input was used to generate this segment: 2016-10-14T00:00:00 2016-10-19T17:28:55 0 0 0 0 0 0.20943951023932 2016-10-19T17:28:55 2016-10-19T18:24:04 0 0 0 0 0 0.52359877559830 2016-10-19T18:24:04 2016-10-28T23:00:00 0 0 0 0 0 0.20943951023932 ******************************************************************************** RUN-TIME OBTAINED META INFORMATION: ******************************************************************************** PRODUCT_CREATION_TIME = 2015-12-09T01:03:07 START_TIME = 2016-10-14T00:00:00.000 STOP_TIME = 2016-10-28T23:00:00.000 ******************************************************************************** INTERPOLATION INTERVALS IN THE FILE SEGMENTS: ******************************************************************************** SEG.SUMMARY: ID -61000, COVERG: 2016-10-14T00:00:00.000 2016-10-28T23:00:00.000 -------------------------------------------------------------------------------- 2016-10-14T00:00:00.000 2016-10-28T23:00:00.000 ******************************************************************************** End of comments.