API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: May 07, 2025 Akatsuki / VCO / Planet-C (spacecraft) -5 http://www.stp.isas.jaxa.jp/venus/E_plan.html http://www.jaxa.jp/projects/sat/planet_c/index_e.html http://global.jaxa.jp/projects/sat/planet_c/topics.html#topics5594 This JAXA mission (Japan) was launched 2010-May-20 21:58:22 a.m UTC from Tanegashima Space Center on an H-IIA F17. It separated from the booster at 27 minutes and 29 seconds after liftoff. Five payloads were on launcher, including the Ikaros solar sail [successfully deployed]: http://www.spaceflightnow.com/h2a/akatsuki/ikaros.pdf English translation blog: http://www.isas.jaxa.jp/home/IKAROS-blog/ ... and Unitec-1 interplanetary amateur radio relay [LOS shortly thereafter]: http://www.oz9aec.net/index.php/gnu-radio/gnu-radio-blog/309-unitec-1-a-new-deep-space-adventure http://www.unisec.jp/unitec-1/files/text/UNITEC-1operation_en.pdf MISSION DESCRIPTION The Venus Climate Orbiter mission (PLANET-C), will study the atmospheric circulation of Venus over a nominal mission of 4.5 years. Meteorological information will be obtained by globally mapping clouds and constituents successively with 5 cameras at ultraviolet and infrared wavelengths, detecting lightning with a high-speed imagery, and observing the vertical structure of the atmosphere with radio science techniques. The equatorial elongated orbit with westward revolution suits the movement and temporal variation of the Venusian atmosphere, which rotates westward. The systematic, continuous imaging observations will provide an unprecedented large dataset of the Venusian atmospheric dynamics. Additional targets of the mission are the exploration of the ground surface and the observation of zodiacal light. Regular science operations were conducted May 2016 through April 2018, with extended operations thereafter. UPDATE (2016-Mar-26): Another maneuver lowered apoapsis to 330000 km and shortened the orbit period to 9 days. UPDATE (2015-Dec-07): The second orbit insertion attempt, a 20 minute burn, was successful and the spacecraft is orbiting Venus. Initial orbit was 400 x 44000 km from surface with period 13.5833 days. UPDATE (2014-Dec-16): A second Venus orbit insertion maneuver attempt will be made in December 2015. This will require 4 manuevers between 2015-Jul-17 and 2015-Sep-11. UPDATE (2010-Dec-08): Orbit insertion failed at Venus on Dec 6, 2010 23:49 UTC. The spacecraft entered safe mode prior to completing the orbit insertion burn, so continued past the planet. Another attempt may be possible in 6 years if spacecraft systems survive. [Salt deposits jamming the valve between the helium pressurization tank and the fuel tank were later determined to be the cause of the malfunction]. SPACECRAFT * Box shape with two wing-type solar array paddles (1.04 meters x 1.45 meters x 1.4 meters) * Mass at liftoff: about 500 kg * Mass of science payload: 34 kg * Generated Power in Venus Orbit: 700 W to about 500 W (at end of mission) SCIENTIFIFC EQUIPMENT - 1-m camera (IR1) / Low stratus, vapor, active volcanism - 2-m camera (IR2) / Low stratus, trace gasses, zodiacal light - Long wave infrared camera (LIR) / Cloud-top temperature distribution - Ultraviolet imager (UVI) / Cloud-top ultraviolet absorber, SO2 - Lightening and airglow camera: (LAC)/Lightning flash, high-stratus airglow emission - Ultra-stable Oscillator (USO) / Atmospheric temperature structure SPACECRAFT TRAJECTORY (ISAS/JAXA/JPL navigation team): Planetary ephemeris: DE423 to 2015-04-08 06:00:00, DE430 thereafter. Final reconstruction fit to tracking data up to 2024-Jan-01. Preliminary solution 2024-Jan-01 to 2025-Apr-23, prediction thereafter. Trajectory name Start (TDB) Stop (TDB) -------------------------------------- ----------------- --------------- vco_2010_v01 ....... vc_2022_v01 2010-May-21 00:53 2024-Jan-01 *-ISAS.OEM 2024-Jan-01 2025-May-25 ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Tue May 13 10:09:24 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Planet-C (spacecraft) (-5) {source: planet-c_merged} Center body name: Earth (399) {source: planet-c_merged} Center-site name: Swan Reach Imaging, Glenalta ******************************************************************************* Start time : A.D. 2024-Oct-31 00:00:00.0000 UT Stop time : A.D. 2024-Nov-01 00:00:00.0000 UT Step-size : 10 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 139.5701, -34.5440227, .056888 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 139.5701,5259.32258,-3596.34777 {E-lon(deg),Dxy(km),Dz(km)} Center pole/equ : ITRF93 {East-longitude positive} Center radii : 6378.137, 6378.137, 6356.752 km {Equator_a, b, pole_c} Target primary : Venus Vis. interferer : MOON (R_eq= 1737.400) km {source: planet-c_merged} Rel. light bend : Sun {source: planet-c_merged} Rel. lght bnd GM: 1.3271E+11 km^3/s^2 Atmos refraction: NO (AIRLESS) RA format : HMS Time format : CAL Calendar mode : Mixed Julian/Gregorian RTS-only print : NO EOP file : eop.250512.p250808 EOP coverage : DATA-BASED 1962-JAN-20 TO 2025-MAY-12. PREDICTS-> 2025-AUG-07 Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s Table cut-offs 1: Elevation ( 0.0deg=YES),Airmass (>38.000=NO), Daylight (YES) Table cut-offs 2: Solar elongation ( 12.0,180.0=YES),Local Hour Angle( 0.0=NO ) Table cut-offs 3: RA/DEC angular rate ( 0.0=NO ) *************************************************************************************************************************************************************************************************************************************************** Date__(UT)__HR:MN R.A._____(ICRF)_____DEC Azi____(a-app)___Elev APmag S-brt r rdot delta deldot S-O-T /r S-T-O T-O-M/MN_Illu% RA_3sigma DEC_3sigma Sky_motion Sky_mot_PA RelVel-ANG *************************************************************************************************************************************************************************************************************************************************** $$SOE >..... Daylight Cut-off Requested .....< 2024-Oct-31 09:20 C 16 58 10.59 -24 25 12.6 261.611547 33.621846 n.a. n.a. 0.727005927024 -1.0019300 1.17972018071008 -11.0521566 37.8832 /T 56.9765 51.1/ 1.3630 n.a. n.a. 2.9227556 97.640091 -14.85564 2024-Oct-31 09:30 C 16 58 12.71 -24 25 16.5 260.399569 31.590091 n.a. n.a. 0.727001912897 -0.9996802 1.17967585924104 -11.0470991 37.8843 /T 56.9793 51.0/ 1.3454 n.a. n.a. 2.9240021 97.630338 -14.84363 2024-Oct-31 09:40 N 16 58 14.83 -24 25 20.5 259.197183 29.565571 n.a. n.a. 0.726997907779 -0.9974380 1.17963155685182 -11.0426449 37.8855 /T 56.9820 51.0/ 1.3277 n.a. n.a. 2.9252700 97.620916 -14.83230 2024-Oct-31 09:50 N 16 58 16.95 -24 25 24.4 258.000862 27.549131 n.a. n.a. 0.726993911639 -0.9952032 1.17958727110076 -11.0388047 37.8867 /T 56.9848 50.9/ 1.3098 n.a. n.a. 2.9265571 97.611835 -14.82167 2024-Oct-31 10:00 N 16 58 19.08 -24 25 28.4 256.807363 25.541621 n.a. n.a. 0.726989924448 -0.9929759 1.17954299950603 -11.0355878 37.8878 /T 56.9876 50.8/ 1.2919 n.a. n.a. 2.9278616 97.603107 -14.81177 2024-Oct-31 10:10 A 16 58 21.20 -24 25 32.3 255.613677 23.543902 n.a. n.a. 0.726985946175 -0.9907560 1.17949873955060 -11.0330024 37.8890 /T 56.9903 50.7/ 1.2739 n.a. n.a. 2.9291812 97.594742 -14.80261 2024-Oct-31 10:20 A 16 58 23.33 -24 25 36.3 254.416982 21.556857 n.a. n.a. 0.726981976792 -0.9885434 1.17945448868692 -11.0310555 37.8902 /T 56.9931 50.6/ 1.2558 n.a. n.a. 2.9305139 97.586749 -14.79421 2024-Oct-31 10:30 A 16 58 25.46 -24 25 40.2 253.214607 19.581396 n.a. n.a. 0.726978016268 -0.9863380 1.17941024434191 -11.0297528 37.8913 /T 56.9958 50.5/ 1.2377 n.a. n.a. 2.9318575 97.579139 -14.78659 2024-Oct-31 10:40 A 16 58 27.58 -24 25 44.1 252.004004 17.618459 n.a. n.a. 0.726974064576 -0.9841398 1.17936600392185 -11.0290990 37.8925 /T 56.9986 50.4/ 1.2195 n.a. n.a. 2.9332100 97.571918 -14.77977 2024-Oct-31 10:50 16 58 29.71 -24 25 48.1 250.782717 15.669026 n.a. n.a. 0.726970121686 -0.9819487 1.17932176481743 -11.0290972 37.8937 /T 57.0013 50.3/ 1.2013 n.a. n.a. 2.9345690 97.565094 -14.77376 2024-Oct-31 11:00 16 58 31.84 -24 25 52.0 249.548362 13.734120 n.a. n.a. 0.726966187571 -0.9797646 1.17927752440868 -11.0297495 37.8948 /T 57.0041 50.2/ 1.1830 n.a. n.a. 2.9359325 97.558674 -14.76857 2024-Oct-31 11:10 16 58 33.97 -24 25 55.9 248.298612 11.814813 n.a. n.a. 0.726962262202 -0.9775875 1.17923328007005 -11.0310566 37.8960 /T 57.0068 50.1/ 1.1647 n.a. n.a. 2.9372983 97.552663 -14.76421 2024-Oct-31 11:20 16 58 36.11 -24 25 59.9 247.031174 9.912235 n.a. n.a. 0.726958345551 -0.9754173 1.17918902917542 -11.0330180 37.8972 /T 57.0095 50.0/ 1.1464 n.a. n.a. 2.9386641 97.547067 -14.76069 2024-Oct-31 11:30 16 58 38.24 -24 26 03.8 245.743783 8.027573 n.a. n.a. 0.726954437590 -0.9732540 1.17914476910319 -11.0356321 37.8984 /T 57.0123 49.9/ 1.1281 n.a. n.a. 2.9400277 97.541889 -14.75802 2024-Oct-31 11:40 16 58 40.37 -24 26 07.7 244.434185 6.162085 n.a. n.a. 0.726950538292 -0.9710975 1.17910049724128 -11.0388958 37.8995 /T 57.0150 49.8/ 1.1098 n.a. n.a. 2.9413869 97.537133 -14.75620 2024-Oct-31 11:50 16 58 42.51 -24 26 11.7 243.100135 4.317099 n.a. n.a. 0.726946647631 -0.9689478 1.17905621099215 -11.0428048 37.9007 /T 57.0177 49.7/ 1.0916 n.a. n.a. 2.9427396 97.532802 -14.75524 2024-Oct-31 12:00 16 58 44.64 -24 26 15.6 241.739384 2.494023 n.a. n.a. 0.726942765578 -0.9668047 1.17901190777775 -11.0473537 37.9019 /T 57.0205 49.6/ 1.0733 n.a. n.a. 2.9440836 97.528896 -14.75514 2024-Oct-31 12:10 16 58 46.78 -24 26 19.5 240.349680 0.694348 n.a. n.a. 0.726938892108 -0.9646682 1.17896758504453 -11.0525358 37.9031 /T 57.0232 49.5/ 1.0552 n.a. n.a. 2.9454166 97.525418 -14.75591 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< $$EOE *************************************************************************************************************************************************************************************************************************************************** Column meaning: TIME Times PRIOR to 1962 are UT1, a mean-solar time closely related to the prior but now-deprecated GMT. Times AFTER 1962 are in UTC, the current civil or "wall-clock" time-scale. UTC is kept within 0.9 seconds of UT1 using integer leap-seconds for 1972 and later years. Conversion from the internal Barycentric Dynamical Time (TDB) of solar system dynamics to the non-uniform civil UT time-scale requested for output has not been determined for UTC times after the next July or January 1st. Therefore, the last known leap-second is used as a constant over future intervals. Time tags refer to the UT time-scale conversion from TDB on Earth regardless of observer location within the solar system, although clock rates may differ due to the local gravity field and no analog to "UT" may be defined for that location. Any 'b' symbol in the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D. date. CALENDAR SYSTEM Mixed calendar mode was active such that calendar dates after AD 1582-Oct-15 (if any) are in the modern Gregorian system. Dates prior to 1582-Oct-5 (if any) are in the Julian calendar system, which is automatically extended for dates prior to its adoption on 45-Jan-1 BC. The Julian calendar is useful for matching historical dates. The Gregorian calendar more accurately corresponds to the Earth's orbital motion and seasons. A "Gregorian-only" calendar mode is available if such physical events are the primary interest. NOTE: "n.a." in output means quantity "not available" at the print-time. SOLAR PRESENCE (OBSERVING SITE) Time tag is followed by a blank, then a solar-presence condition code: '*' Daylight (refracted solar upper-limb on or above apparent horizon) 'C' Civil twilight/dawn 'N' Nautical twilight/dawn 'A' Astronomical twilight/dawn ' ' Night OR geocentric ephemeris LUNAR PRESENCE WITH TARGET RISE/TRANSIT/SET EVENT MARKER (OBSERVING SITE) The solar-presence code column is immediately followed by another marker: 'm' Refracted upper-limb of Moon on or above apparent horizon ' ' Refracted upper-limb of Moon below apparent horizon OR geocentric The lunar presence marker (an ongoing state) can be over-ridden by a target event marker if an event has occurred since the last output step: 'r' Rise (target body on or went above cut-off RTS elevation) 'e' Elevation max (target body maximum elevation angle has occurred) 't' Transit (target body at or passed through observer meridian) 's' Set (target body on or went below cut-off RTS elevation) RTS MARKERS (TVH) Rise and set are with respect to the reference ellipsoid true visual horizon defined by the elevation cut-off angle. Horizon dip and yellow-light refraction (Earth only) are considered. Accuracy is < or = to twice the requested search step-size. 'R.A._____(ICRF)_____DEC' = Astrometric right ascension and declination of the target center with respect to the observing site (coordinate origin) in the reference frame of the planetary ephemeris (ICRF). Compensated for down-leg light-time delay aberration. Units: RA in hours-minutes-seconds of time, HH MM SS.ff{ffff} DEC in degrees-minutes-seconds of arc, sDD MN SC.f{ffff} 'Azi____(a-app)___Elev' = Airless apparent azimuth and elevation of target center. Compensated for light-time, the gravitational deflection of light, stellar aberration, precession and nutation. Azimuth is measured clockwise from north: North(0) -> East(90) -> South(180) -> West(270) -> North (360) Elevation angle is with respect to a plane perpendicular to the reference surface local zenith direction. TOPOCENTRIC ONLY. Units: DEGREES 'APmag S-brt' = The targets' approximate apparent visual magnitude and surface brightness. For planets and natural satellites, output is restricted to solar phase angles covered by observational data. Outside the observed phase angle range, "n.a." may be output to avoid extrapolation beyond the limit of model validity. For Earth-based observers, the estimated dimming due to atmospheric absorption (extinction) is available as a separate, requestable quantity. Surface brightness is the average airless visual magnitude of a square-arcsecond of the illuminated portion of the apparent disk. It is computed only if the target radius is known. Units: MAGNITUDES & MAGNITUDES PER SQUARE ARCSECOND 'r rdot' = The Sun's apparent range ("r", light-time aberrated) and range-rate ("rdot") relative to the target center, as seen by the observer. A positive "rdot" means the target center was moving away from the Sun, negative means moving toward the Sun. Units: AU and KM/S 'delta deldot' = Apparent range ("delta", light-time aberrated) and range-rate ("delta-dot") of the target center relative to the observer. A positive "deldot" means the target center is moving away from the observer, negative indicates movement toward the observer. Units: AU and KM/S 'S-O-T /r' = Sun-Observer-Target apparent SOLAR ELONGATION ANGLE seen from the observers' location at print-time. The '/r' column provides a code indicating the targets' apparent position relative to the Sun in the observers' sky, as described below: Case A: For an observing location on the surface of a rotating body, that body rotational sense is considered: /T indicates target TRAILS Sun (evening sky: rises and sets AFTER Sun) /L indicates target LEADS Sun (morning sky: rises and sets BEFORE Sun) Case B: For an observing point that does not have a rotational model (such as a spacecraft), the "leading" and "trailing" condition is defined by the observers' heliocentric ORBITAL motion: * If continuing in the observers' current direction of heliocentric motion would encounter the targets' apparent longitude first, followed by the Sun's, the target LEADS the Sun as seen by the observer. * If the Sun's apparent longitude would be encountered first, followed by the targets', the target TRAILS the Sun. Two other codes can be output: /* indicates observer is Sun-centered (undefined) /? Target is aligned with Sun center (no lead or trail) The S-O-T solar elongation angle is numerically the minimum separation angle of the Sun and target in the sky in any direction. It does NOT indicate the amount of separation in the leading or trailing directions, which would be defined along the equator of a spherical coordinate system. Units: DEGREES 'S-T-O' = The Sun-Target-Observer angle; the interior vertex angle at target center formed by a vector from the target to the apparent center of the Sun (at reflection time on the target) and the apparent vector from target to the observer at print-time. Slightly different from true PHASE ANGLE (requestable separately) at the few arcsecond level in that it includes stellar aberration on the down-leg from target to observer. Units: DEGREES 'T-O-M/MN_Illu%' = Target-Observer-Moon LUNAR ELONGATION angle and illuminated percentage. The apparent lunar elongation angle between target body center and Moon center, seen from the observing site, along with fraction of the lunar disk illuminated by the Sun. A negative lunar elongation angle indicates the target center is behind the Moon. Units: DEGREES & PERCENT 'RA_3sigma DEC_3sigma' = Uncertainty in Right-Ascension and Declination. Output values are the formal +/- 3 standard-deviations (sigmas) around nominal position. Units: ARCSECONDS 'Sky_motion Sky_mot_PA RelVel-ANG' = Total apparent angular rate of the target in the plane-of-sky. "Sky_mot_PA" is the position angle of the target's direction of motion in the plane-of-sky, measured counter-clockwise from the apparent of-date north pole direction. "RelVel-ANG" is the flight path angle of the target's relative motion with respect to the observer's line-of-sight, in the range [-90,+90], where positive values indicate motion away from the observer, negative values are toward the observer: -90 = target is moving directly toward the observer 0 = target is moving at right angles to the observer's line-of-sight +90 = target is moving directly away from the observer UNITS: ARCSECONDS/MINUTE, DEGREES, DEGREES Computations by ... Solar System Dynamics Group, Horizons On-Line Ephemeris System 4800 Oak Grove Drive, Jet Propulsion Laboratory Pasadena, CA 91109 USA General site: https://ssd.jpl.nasa.gov/ Mailing list: https://ssd.jpl.nasa.gov/email_list.html System news : https://ssd.jpl.nasa.gov/horizons/news.html User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/x API https://ssd-api.jpl.nasa.gov/doc/horizons.html command-line telnet ssd.jpl.nasa.gov 6775 e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/horizons_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************