JUNO Reference Orientation CK File ============================================================= Created on May 22, 2018 by Martin Brennan, JPL. Summary ------------------------------------------------------------- This file contains STUDY attitude profile for PJ20 using the latest reference trajectory (spk_ref_180429_210731_180509.bsp). The CK spans the Orbit 20 sequences: jm0201 and jm0202 (PJ20-24h to PJ21-24h). The PJ20 STUDY orientation is defined as a MWR -30/+5 attitude with -30 deg azimuth (towards Jupiter dawn) / +5 deg elevation (towards Jupiter N. Pole) offsets measured from Jupiter-Sun vector. No truncation is necessary since the Off-Sun angle is less than 35 deg (30.375 deg). Start: 28 MAY 2019 08:00:00.000 UTC Stop : 20 JUL 2019 04:00:00.000 UTC The attitude mode for each perijove pass is listed below: PJ 00 JOI PJ 01 GRAV PJ 02 GRAV PJ 03 GRAV PJ 04 MWR PJ 05 MWR-tilt PJ 06 GRAV PJ 07 MWR PJ 08 GRAV PJ 09 MWR-tilt w/ 35deg-offset PJ 10 GRAV PJ 11 GRAV PJ 12 MWR -30/+20deg-offset PJ 13 GRAV PJ 14 GRAV PJ 15 GRAV PJ 16 MWR -30/+20deg-offset PJ 17 GRAV PJ 18 GRAV PJ 19 MWR-crosstrack (JUNO +Z aligned with JUPITER +Z) PJ 20 MWR -30/+5deg-offset PJ 21 GRAV PJ 22 GRAV PJ 22 GRAV PJ 23 GRAV PJ 24 GRAV PJ 25 GRAV PJ 26 GRAV PJ 27 GRAV PJ 28 GRAV PJ 29 GRAV PJ 30 GRAV PJ 31 GRAV PJ 32 GRAV PJ 33 GRAV PJ 34 GRAV PJ 35 Deorbit (But modeled as EarthPoint) 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 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. Coverage ------------------------------------------------------------- This file provides continuous coverage for the following time period: Begin TDB End TDB ------------------------ ------------------------ 2019-05-28/08:01:09.185 2019-07-20/04:01:09.184 Related Kernels ------------------------------------------------------------- This was generated and must be used together with the following kernels: Type Name ---- ------------------------------------------ LSK naif0012.tls SCLK JNO_SCLKSCET.00072.tsc FK juno_v12.tf SPK jup310.bsp SPK spk_ref_180429_210731_180509.bsp Contact Information ------------------------------------------------------------- Contact Marty Brennan (martin.brennan@jpl.nasa.gov), or Stuart Stephens (stuart.k.stephens@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 2018-MAY-23 14:30:39. The following files were provided in support of the construction of the attitude given in this kernel. File Type Name ---- ------------------------------------------ SPK /Users/mbrennan/Documents/JUNO/SPICE/spk/jup310.bsp SPK /Users/mbrennan/Documents/JUNO/SPICE/spk/spk_ref_180429_210731_180509.bsp TEXT /Users/mbrennan/Documents/JUNO/SPICE/lsk/naif0012.tls TEXT /Users/mbrennan/Documents/JUNO/SPICE/pck/pck00010.tpc 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. This file contains STUDY attitude profile for PJ20 using the latest reference trajectory (spk_ref_180429_210731_180509.bsp). The CK spans the Orbit 20 sequences: jm0201 and jm0202 (PJ20-24h to PJ21-24h). The PJ20 STUDY orientation is defined as a MWR -30/+5 attitude with -30 deg azimuth (towards Jupiter dawn) / +5 deg elevation (towards Jupiter N. Pole) offsets measured from Jupiter-Sun vector. No truncation is necessary since the Off-Sun angle is less than 35 deg (30.375 deg). Start: 28 MAY 2019 08:00:00.000 UTC Stop : 20 JUL 2019 04:00:00.000 UTC These segments were generated using PREDICKT with the direction, orientation, and schedule specifications provided below based on the spreadsheet data. The attitude mode for each Perijove pass is listed below: PJ 20 MWR -30/+5deg-offset 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 deg about JUNOPOS. SUNOFFN30P20 is a truncated MWR -30 deg azimuth (towards Jupiter dawn) / +20 deg elevation (towards Jupiter N. Pole) offset from Jupiter-Sun vector for PJ16, set to achieve a 35 deg Sun-offset. SUNOFFN30P5 is an untruncated MWR -30 deg azimuth (towards Jupiter dawn) / +5 deg elevation (towards Jupiter N. Pole) offset from Jupiter-Sun vector for PJ20. ECLIPN is the +Z axis (North pole) of the Ecliptic of J2000 inertial frame (ECLIPJ2000). JOIZ is the reference direction for +Z axis during JOI burn -- RA=268.422 deg, Dec=62.359 deg in EME2000. PRMZ is the reference direction for +Z axis during PRM burn -- RA=268.381 deg, Dec=60.061 deg in EME2000. DEORBITZ is the reference direction for +Z axis during the Deorbit burn -- RA=153.68 deg, Dec=12.39 deg in EME2000. (BUT USES EARTHPOINT) ORBXEARTH is the vector normal to the TOEARTH and JUNOORB vectors in the direction of Jupiter's +Z body axis HALFMWR is an intermediate vector between the TOSUN and -JUNOORB vectors. The TOSUN vector is rotated -20 deg about the ORBXEARTH vector. JUPN is the Jupiter North Pole vector defined in the J2000 frame. \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 += ( 'JOIZ = FIXED J2000 -' ) DIRECTION_SPECS += ( 'RA 268.422 DEGREES -' ) DIRECTION_SPECS += ( 'DEC 62.359 DEGREES ' ) DIRECTION_SPECS += ( 'PRMZ = FIXED J2000 -' ) DIRECTION_SPECS += ( 'RA 268.381 DEGREES -' ) DIRECTION_SPECS += ( 'DEC 60.061 DEGREES ' ) DIRECTION_SPECS += ( 'DEORBITZ = FIXED J2000 -' ) DIRECTION_SPECS += ( 'RA 153.68 DEGREES -' ) DIRECTION_SPECS += ( 'DEC 12.39 DEGREES ' ) DIRECTION_SPECS += ( 'ORBXEARTH = CROSS PRODUCT -' ) DIRECTION_SPECS += ( 'TOEARTH JUNOORB ' ) DIRECTION_SPECS += ( 'HALFMWR = ROTATE TOSUN -' ) DIRECTION_SPECS += ( '-20 DEGREES -' ) DIRECTION_SPECS += ( 'ABOUT ORBXEARTH ' ) DIRECTION_SPECS += ( 'JUPN = FIXED IAU_JUPITER -' ) DIRECTION_SPECS += ( 'XYZ 0 0 1' ) DIRECTION_SPECS += ( 'SUNOFFN30P20 = FIXED J2000 -' ) DIRECTION_SPECS += ( 'RA 22.52519640 DEGREES -' ) DIRECTION_SPECS += ( 'DEC 29.76854369 DEGREES ' ) DIRECTION_SPECS += ( 'SUNOFFN30P5 = FIXED J2000 -' ) DIRECTION_SPECS += ( 'RA 44.39420205 DEGREES -' ) DIRECTION_SPECS += ( 'DEC 21.85059386 DEGREES ' ) \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. MWRNON orientation has -Z along JUNO orbital momentum vector (POS cross VEL) and Ecliptic North pole defining the ZX plane. MWRPON orientation has +Z along JUNO orbital momentum vector (POS cross VEL) and Ecliptic North pole defining the ZX plane. MWRNONTILT14 orientation has -Z along JUNO orbital momentum vector (POS cross VEL) rotated by -14 deg about POS and Ecliptic North pole defining the ZX plane. MWRN30P20 orientation has +Z along -30 deg azimuth (towards Jupiter dawn) / +20 deg elevation (towards Jupiter N. Pole) offset from Jupiter-Sun vector, but is truncated in order to achieve a 35 deg Sun-offset at PJ16. MWRN30P5 orientation has +Z along -30 deg azimuth (towards Jupiter dawn) / +5 deg elevation (towards Jupiter N. Pole) offset from Jupiter-Sun vector and is untruncated for PJ20, since the off-Sun angle is less than 35 deg (30.375 deg). MWRPONTILT14 orientation has +Z along JUNO orbital momentum vector (POS cross VEL) rotated by -14 deg about POS and Ecliptic North pole defining the ZX plane. MWRCROSSTRACK orientation has +Z aligned with Jupiter North Pole vector and the Sun defining the ZX plane. JOIBURN orientation has +Z along the reference direction during the JOI burn and Ecliptic North pole defining the ZX plane. PRMBURN orientation has +Z along the reference direction during the PRM burn and Ecliptic North pole defining the ZX plane. DEORBITBURN orientation has +Z along the reference direction during the DEORBIT burn and Ecliptic North pole defining the ZX plane. HALFMWRATTITUDE orientation has +Z along the reference direction HALFMWR and Ecliptic North pole defining 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 += 'MWRNON' PRIMARY += '-Z = JUNOORB' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRPON' PRIMARY += '+Z = JUNOORB' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRNONTILT14' PRIMARY += '-Z = JUNOORB14' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRN30P20' PRIMARY += '+Z = SUNOFFN30P20' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRN30P5' PRIMARY += '+Z = SUNOFFN30P5' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRPONTILT14' PRIMARY += '+Z = JUNOORB14' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWRCROSSTRACK' PRIMARY += '+Z = JUPN' SECONDARY += '-X = TOSUN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'JOIBURN' PRIMARY += '+Z = JOIZ' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'PRMBURN' PRIMARY += '+Z = PRMZ' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'DEORBITBURN' PRIMARY += '+Z = DEORBITZ' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'HALFMWRATTITUDE' PRIMARY += '+Z = HALFMWR' 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 TDB (Barycentric Dynamic Time). Gaps between attitude modes result in smooth turns from one attitude to the next. \begindata CK-SCLK = 61 CK-SPK = -61 CK-FRAMES = -61900 CK-61900ORIENTATION += 'EARTHPOINTED' CK-61900START += @2019-05-28/08:01:09.185 CK-61900STOP += @2019-05-28/12:21:53.100 \begintext ******************* PJ20 ****************** \begindata CK-61900ORIENTATION += 'MWRN30P5 AT 2019-05-29/08:17:51.196' CK-61900START += @2019-05-28/12:26:53.100 CK-61900STOP += @2019-05-29/14:27:53.100 CK-61900ORIENTATION += 'EARTHPOINTED' CK-61900START += @2019-05-29/14:32:53.100 CK-61900STOP += @2019-07-20/04:01:09.184 \begintext Appendix 2: Information for Rotation About Spin Axis Segment ============================================================= ******************************************************************************** MSOPCK SETUP FILE: juno_sc_nom_190528_190720_study_pj20_n30p5_v01_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). Spin Rate Start UTC End UTC Note --------- ----------------- ----------------- -------- 2 rpm 05/28/19 08:00:00 07/20/19 04:00:00 The profile above was converted to the following input provided to MSOPCK to make this segment (the columns are: start time, stop time, initial orientation as three angles set to zero, and angular velocity representing CCW rotation about +Z): 2019-05-28/08:01:09TDB 2019-07-20/04:01:09TDB 0 0 0 0 0 0.20943951023932 The following MSOPCK setup parameters were used to generate this segment: \begindata LSK_FILE_NAME = '../../SPICE/lsk/naif0012.tls' SCLK_FILE_NAME = '../../SPICE/sclk/JNO_SCLKSCET.00072.tsc' FRAMES_FILE_NAME = '../../SPICE/fk/juno_v12.tf' INTERNAL_FILE_NAME = 'JUNO REF SPIN ATTITUDE, 05/22/18' CK_TYPE = 2 CK_SEGMENT_ID = 'JUNO REF SPIN ATTITUDE, 05/22/18' 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 = 2018-05-23T14:31:02 START_TIME = 2019-05-28T07:59:59.815 STOP_TIME = 2019-07-20T03:59:59.816 ******************************************************************************** INTERPOLATION INTERVALS IN THE FILE SEGMENTS: ******************************************************************************** SEG.SUMMARY: ID -61000, COVERG: 2019-05-28T07:59:59.815 2019-07-20T03:59:59.816 -------------------------------------------------------------------------------- 2019-05-28T07:59:59.815 2019-07-20T03:59:59.816 ******************************************************************************** End of comments.