API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ****************************************************************************** Revised: Jul 05, 2025 Hera / (Sun) -91 https://www.dlr.de/en/ar/topics-missions/space-safety/hera https://esamultimedia.esa.int/docs/HERA_Launch_Kit.pdf Launch Date: Didymos Arrival Date: 2024-Oct-07 14:52 UTC Late 2026 Launch Vehicle: Launch Site: SpaceX Falcon 9 Cape Canaveral, SFS MILESTONES 2024-Nov : DSM-1 2025-Mar : Mars flyby (~6000 km from Mars, ~1000 km from Deimos) 2026-Feb : DSM-2 2026-Oct : Rendevous maneuver Late 2026 : Didymos/Dimorphos system arrival OBJECTIVES: Assess the size and depth of the crater on the 151-m diameter asteroidal moon Dimorphos, created by NASA's DART (Double Asteroid Redirection Test) spacecraft 2022-Sep-26, and determine whether the impact reshaped the rubble pile object that orbits 65803 Didymos at a distance of 1.1 km every 11h 22m, as preliminary results indicate. Once deployed, two CubeSats ("Milani" and "Juventas") will be used to assess Dimorphos' internal structure, surface minerals, as well as gravity. The data will help correctly reproduce the asteroid's final structure and inform future planetary defense missions. SPACECRAFT PHYSICAL PROPERTIES: 1.6 x 1.6 x 1.7 m box Two 5-m solar panel arms (deployed) 1801 kg fully fueled (hydrazine bipropellant) 3-axis stabilization 4 reaction wheels, gyroscopes, star trackers, solar sensors SCIENCE INSTRUMENTS Asteroid Framing Camera (AFC) Thermal Infrared Imager (TIRI) HyperScout-H camera Spacecraft Monitoring Camera (SMC) Laser Rangefinder X-band antenna radio science Gravimeter for the Investigation of Small Solar System Two deployable CubeSats (eventual landing) Juventas: Radar Juventas: Narrow Angle Camera Milani : Narrow Angle Camera Milani : Asteroid Spectral Imager Milani : Volatile In-Situ Thermogravimetre Analyser SPACECRAFT TRAJECTORY: Post-launch tracking-data based trajectory from ESA 2025-Jun-23. Prediction thereafter. Name Start (TDB) Stop (TDB) --------------------------------------- ----------------- ----------------- hera_fcp_000053_241007_261118_v01 2024-Oct-07 16:10 2026-Nov-18 01:59 ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Fri Jul 11 18:33:18 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Hera (spacecraft) (-91) {source: hera_current} Center body name: Earth (399) {source: DE441} 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 : Earth Vis. interferer : MOON (R_eq= 1737.400) km {source: DE441} Rel. light bend : Sun {source: DE441} 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.250711.p251007 EOP coverage : DATA-BASED 1962-JAN-20 TO 2025-JUL-11. PREDICTS-> 2025-OCT-06 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 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< 2024-Oct-31 16:20 r 08 32 47.81 +33 43 13.9 48.204120 -0.500471 n.a. n.a. 1.003761985995 2.7257977 0.07680545708308 4.9773333 96.1072 /L 79.5303 87.6/ 0.6450 n.a. n.a. 0.2645474 312.21905 87.174997 2024-Oct-31 16:30 08 32 47.64 +33 43 15.6 46.775397 1.021770 n.a. n.a. 1.003772921049 2.7271619 0.07682542998538 4.9835685 96.1146 /L 79.5219 87.7/ 0.6312 n.a. n.a. 0.2736321 309.23094 87.081042 2024-Oct-31 16:40 08 32 47.47 +33 43 17.3 45.308829 2.508302 n.a. n.a. 1.003783861573 2.7285260 0.07684542897014 4.9903388 96.1221 /L 79.5133 87.8/ 0.6178 n.a. n.a. 0.2828688 306.42752 86.985992 2024-Oct-31 16:50 08 32 47.28 +33 43 19.0 43.803296 3.957189 n.a. n.a. 1.003794807568 2.7298900 0.07686545615671 4.9976308 96.1296 /L 79.5048 87.9/ 0.6045 n.a. n.a. 0.2921807 303.79329 86.890690 2024-Oct-31 17:00 08 32 47.08 +33 43 20.6 42.257758 5.366413 n.a. n.a. 1.003805759033 2.7312539 0.07688551360855 5.0054301 96.1372 /L 79.4962 88.0/ 0.5916 n.a. n.a. 0.3014974 301.31310 86.795902 2024-Oct-31 17:10 08 32 46.87 +33 43 22.1 40.671271 6.733882 n.a. n.a. 1.003816715967 2.7326177 0.07690560332917 5.0137211 96.1448 /L 79.4875 88.1/ 0.5789 n.a. n.a. 0.3107554 298.97258 86.702318 2024-Oct-31 17:20 08 32 46.64 +33 43 23.6 39.043013 8.057427 n.a. n.a. 1.003827678371 2.7339814 0.07692572725844 5.0224877 96.1524 /L 79.4789 88.2/ 0.5665 n.a. n.a. 0.3198969 296.75821 86.610561 2024-Oct-31 17:30 08 32 46.41 +33 43 25.0 37.372302 9.334815 n.a. n.a. 1.003838646244 2.7353451 0.07694588726875 5.0317124 96.1601 /L 79.4702 88.3/ 0.5543 n.a. n.a. 0.3288694 294.65751 86.521188 2024-Oct-31 17:40 08 32 46.16 +33 43 26.3 35.658624 10.563746 n.a. n.a. 1.003849619586 2.7367086 0.07696608516149 5.0413771 96.1678 /L 79.4614 88.4/ 0.5424 n.a. n.a. 0.3376252 292.65896 86.434699 2024-Oct-31 17:50 08 32 45.91 +33 43 27.5 33.901661 11.741871 n.a. n.a. 1.003860598396 2.7380721 0.07698632266348 5.0514629 96.1755 /L 79.4527 88.5/ 0.5308 n.a. n.a. 0.3461214 290.75205 86.351542 2024-Oct-31 18:00 08 32 45.64 +33 43 28.7 32.101315 12.866798 n.a. n.a. 1.003871582673 2.7394355 0.07700660142377 5.0619499 96.1833 /L 79.4439 88.6/ 0.5194 n.a. n.a. 0.3543186 288.92716 86.272113 2024-Oct-31 18:10 A 08 32 45.37 +33 43 29.8 30.257740 13.936105 n.a. n.a. 1.003882572419 2.7407988 0.07702692301041 5.0728176 96.1910 /L 79.4351 88.7/ 0.5083 n.a. n.a. 0.3621815 287.17554 86.196766 2024-Oct-31 18:20 A 08 32 45.09 +33 43 30.8 28.371370 14.947357 n.a. n.a. 1.003893567632 2.7421621 0.07704728890752 5.0840446 96.1988 /L 79.4262 88.8/ 0.4975 n.a. n.a. 0.3696779 285.48921 86.125810 2024-Oct-31 18:30 A 08 32 44.80 +33 43 31.8 26.442942 15.898123 n.a. n.a. 1.003904568311 2.7435252 0.07706770051225 5.0956090 96.2066 /L 79.4174 88.9/ 0.4869 n.a. n.a. 0.3767788 283.86088 86.059518 2024-Oct-31 18:40 A 08 32 44.50 +33 43 32.6 24.473523 16.785996 n.a. n.a. 1.003915574457 2.7448883 0.07708815913238 5.1074881 96.2145 /L 79.4085 89.0/ 0.4766 n.a. n.a. 0.3834581 282.28391 85.998127 2024-Oct-31 18:50 N 08 32 44.20 +33 43 33.4 22.464531 17.608615 n.a. n.a. 1.003926586070 2.7462513 0.07710866598348 5.1196586 96.2223 /L 79.3996 89.1/ 0.4666 n.a. n.a. 0.3896924 280.75218 85.941840 2024-Oct-31 19:00 N 08 32 43.89 +33 43 34.1 20.417750 18.363689 n.a. n.a. 1.003937603148 2.7476141 0.07712922218685 5.1320968 96.2302 /L 79.3907 89.2/ 0.4568 n.a. n.a. 0.3954608 279.26007 85.890830 2024-Oct-31 19:10 N 08 32 43.57 +33 43 34.6 18.335341 19.049022 n.a. n.a. 1.003948625692 2.7489770 0.07714982876724 5.1447783 96.2380 /L 79.3818 89.3/ 0.4473 n.a. n.a. 0.4007449 277.80240 85.845238 2024-Oct-31 19:20 Cm 08 32 43.25 +33 43 35.1 16.219847 19.662538 n.a. n.a. 1.003959653701 2.7503397 0.07717048665088 5.1576784 96.2459 /L 79.3729 89.4/ 0.4380 n.a. n.a. 0.4055283 276.37433 85.805181 2024-Oct-31 19:30 Cm 08 32 42.93 +33 43 35.5 14.074183 20.202313 n.a. n.a. 1.003970687174 2.7517023 0.07719119666371 5.1707718 96.2538 /L 79.3639 89.5/ 0.4290 n.a. n.a. 0.4097972 274.97136 85.770747 >..... 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 ***************************************************************************************************************************************************************************************************************************************************