API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: Sep 01, 2026 TESS / (Earth) -95 https://tess.gsfc.nasa.gov/index.html http://spaceflight101.com/tess/tess-orbit-design/ BACKGROUND: The NASA Transiting Exoplanet Survey Satellite (TESS) mission is to detect exoplanets transiting nearby bright stars, targets for followup characterization with large ground telescopes such as the Hubble Space Telescope and the future James Webb Space Telescope. Launched : 2018-Apr-18 22:51 UTC Launch vehicle : Falcon 9 Block 4 Launch site : SLC-40, Cape Canaveral Payload mass : 362 kg Ascent duration : 49 minutes, then TESS deployment A SpaceX Falcon 9 launched the 362-kilogram TESS spacecraft into a Suprasynchronous Transfer Orbit of 200 by 270,000 kilometers at an inclination of 28.5 degrees. The operational orbit chosen for TESS is a highly eccentric, 2:1 lunar resonance orbit of 108,400 by 376,300 kilometers at an inclination of 37 degrees, timed so that the spacecraft reaches apogee with the moon at a phasing of 90 degrees. 11 maneuvering engine burns, 3.5 phasing loops, and a lunar flyby will be used during the first 60 days to go from the inital transfer orbit to the operational orbit. TESS is designed to: - Monitor 200,000 nearby stars for planets - Detect and characterize Earth and Super-Earth size planets - Cover 400X larger sky area than Kepler - Span stellar spectral types of F5 to M5 Transiting exoplanets allow determination of the following: - Fundamental properties: mass, radius, orbit - Dynamics: planet-planet interactions, mutual inclinations, moons, tides - Atmospheric composition & structure: transmission spectrum, emission spectrum, MISSION OVERVIEW: All-sky, two year photometric exoplanet discovery mission. TESS will tile the sky with 26 observation sectors: - At least 27 days staring at each 24 deg. x 96 deg. sector - Brightest 100,000 stars at 1-minute cadence - Full frame images with 30-minute cadence - Map Northern hemisphere in first year - Map Southern hemisphere in second year - Sectors overlap at ecliptic poles for sensitivity to smaller and longer period planets in JWST Continuous Viewing Zone (CVZ) TESS observes from unique High Earth Orbit (HEO): - Unobstructed view for continuous observation - Two 13.7 day orbits per observation sector - Stable 2:1 resonance with Moon's orbit (P/2) - Thermally stable, low-radiation SPACECRAFT: Designed for photometric stability. Heritage Orbital LEOStar-2 spacecraft bus: - 3-axis stabilized pointing, with <= 3 arcsecong performance - Two-headed star tracker; 4 wheel zero-momentum system - 400W single-axis articulating solar array - Passive thermal control - Mono-propellant propulsion system - Ka-band 100 Mbps science downlink - Hexagonal 3.9 x 1.2 x 1.5 meter dimensions when fully deployed - Two 1.1 x 0.89 m solar panels SCIENCE INSTRUMENT: Four wide field-of-view CCD cameras. Each of the four cameras has: - 24 deg. x 24 deg. Field-of-View - 100 mm effective pupil diameter - Lens assembly with 7 optical elements - Athermal design - 600nm - 1000nm bandpass - 16.8 Megapixel, low-noise, low-power, MIT Lincoln Lab CCID-80 detector Trajectory: Post-launch trajectory (starts after launch ascent, L+00:49 min.). Concatenated short-term tag-up predictions, each covering ~3-4 days: Last tracking data used is 2026-Aug-31, predicts thereafter. Trajectory name Start (TDB) Stop (TDB) ------------------------------------ ----------------- ----------------- Concatenated trajectory files (794) 2018-Apr-18 23:37 2028-Mar-01 13:00 ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Mon Sep 14 13:50:02 2026 Pasadena, USA / Horizons ******************************************************************************* Target body name: TESS (spacecraft) (-95) {source: TESS_merged} Center body name: Earth (399) {source: TESS_merged} Center-site name: iTelescope Obs.,Beryl Junc. (Sato) ******************************************************************************* Start time : A.D. 2026-Sep-02 00:00:00.0000 UT Stop time : A.D. 2026-Sep-05 00:00:00.0000 UT Step-size : 10 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 246.3025, 37.7377919, 1.56349 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 246.3025,5051.53114,3883.42609 {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: TESS_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.260911.p261208 EOP coverage : DATA-BASED 1962-JAN-20 TO 2026-SEP-11. PREDICTS-> 2026-DEC-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 >..... Elevation Cut-off Requested .....< 2026-Sep-04 05:40 m 23 06 40.69 -47 37 14.0 158.769828 0.017189 n.a. n.a. 1.009972550845 -0.4954952 0.00184490891824 -0.6534782 139.5511 /L 40.3809 104.0/ 50.6395 n.a. n.a. 30.215251 49.225931 -44.11887 2026-Sep-04 05:50 m 23 07 03.16 -47 33 54.2 160.236178 0.736256 n.a. n.a. 1.009970559094 -0.4977096 0.00184230222728 -0.6463026 139.5976 /L 40.3346 104.0/ 50.5466 n.a. n.a. 30.319673 48.046221 -43.74448 2026-Sep-04 06:00 m 23 07 25.29 -47 30 29.0 161.726509 1.411423 n.a. n.a. 1.009968558447 -0.4999314 0.00183972480074 -0.6388879 139.6455 /L 40.2868 104.1/ 50.4546 n.a. n.a. 30.462285 46.890152 -43.32014 2026-Sep-04 06:10 m 23 07 47.11 -47 26 58.3 163.239865 2.041467 n.a. n.a. 1.009966548873 -0.5021607 0.00183717757100 -0.6312475 139.6948 /L 40.2376 104.1/ 50.3638 n.a. n.a. 30.642435 45.763244 -42.84729 2026-Sep-04 06:20 m 23 08 08.63 -47 23 21.9 164.775181 2.625210 n.a. n.a. 1.009964530344 -0.5043976 0.00183466141485 -0.6233956 139.7457 /L 40.1869 104.1/ 50.2741 n.a. n.a. 30.859286 44.670616 -42.32778 2026-Sep-04 06:30 m 23 08 29.89 -47 19 39.7 166.331281 3.161522 n.a. n.a. 1.009962502827 -0.5066420 0.00183217715158 -0.6153468 139.7981 /L 40.1347 104.1/ 50.1855 n.a. n.a. 31.111825 43.616923 -41.76381 2026-Sep-04 06:40 m 23 08 50.90 -47 15 51.8 167.906884 3.649330 n.a. n.a. 1.009960466294 -0.5088941 0.00182972554131 -0.6071159 139.8520 /L 40.0809 104.1/ 50.0980 n.a. n.a. 31.398891 42.606302 -41.15790 2026-Sep-04 06:50 m 23 09 11.70 -47 11 57.9 169.500598 4.087628 n.a. n.a. 1.009958420713 -0.5111538 0.00182730728328 -0.5987185 139.9075 /L 40.0256 104.1/ 50.0117 n.a. n.a. 31.719190 41.642338 -40.51286 2026-Sep-04 07:00 m 23 09 32.32 -47 07 58.1 171.110933 4.475482 n.a. n.a. 1.009956366053 -0.5134212 0.00182492301442 -0.5901701 139.9645 /L 39.9687 104.1/ 49.9266 n.a. n.a. 32.071323 40.728050 -39.83176 2026-Sep-04 07:10 m 23 09 52.77 -47 03 52.2 172.736301 4.812038 n.a. n.a. 1.009954302284 -0.5156963 0.00182257330784 -0.5814869 140.0231 /L 39.9103 104.1/ 49.8427 n.a. n.a. 32.453802 39.865886 -39.11787 2026-Sep-04 07:20 m 23 10 13.09 -46 59 40.3 174.375025 5.096529 n.a. n.a. 1.009952229374 -0.5179792 0.00182025867162 -0.5726852 140.0833 /L 39.8503 104.1/ 49.7599 n.a. n.a. 32.865078 39.057738 -38.37460 2026-Sep-04 07:30 m 23 10 33.31 -46 55 22.2 176.025347 5.328283 n.a. n.a. 1.009950147293 -0.5202698 0.00181797954754 -0.5637817 140.1451 /L 39.7887 104.2/ 49.6784 n.a. n.a. 33.303555 38.304968 -37.60550 2026-Sep-04 07:40 m 23 10 53.45 -46 50 58.0 177.685441 5.506727 n.a. n.a. 1.009948056009 -0.5225683 0.00181573631009 -0.5547933 140.2084 /L 39.7255 104.2/ 49.5980 n.a. n.a. 33.767613 37.608437 -36.81418 2026-Sep-04 07:50 m 23 11 13.54 -46 46 27.6 179.353424 5.631391 n.a. n.a. 1.009945955491 -0.5248746 0.00181352926550 -0.5457372 140.2733 /L 39.6608 104.2/ 49.5189 n.a. n.a. 34.255622 36.968546 -36.00426 2026-Sep-04 08:00 t 23 11 33.62 -46 41 51.0 181.027367 5.701916 n.a. n.a. 1.009943845707 -0.5271888 0.00181135865094 -0.5366306 140.3397 /L 39.5945 104.2/ 49.4410 n.a. n.a. 34.765959 36.385282 -35.17938 2026-Sep-04 08:10 e 23 11 53.70 -46 37 08.2 182.705311 5.718054 n.a. n.a. 1.009941726626 -0.5295110 0.00180922463385 -0.5274909 140.4077 /L 39.5267 104.2/ 49.3643 n.a. n.a. 35.297019 35.858260 -34.34310 2026-Sep-04 08:20 m 23 12 13.82 -46 32 19.3 184.385282 5.679669 n.a. n.a. 1.009939598215 -0.5318411 0.00180712731140 -0.5183359 140.4773 /L 39.4573 104.2/ 49.2888 n.a. n.a. 35.847226 35.386772 -33.49891 2026-Sep-04 08:30 m 23 12 34.00 -46 27 24.1 186.065305 5.586741 n.a. n.a. 1.009937460442 -0.5341792 0.00180506671007 -0.5091831 140.5483 /L 39.3865 104.2/ 49.2145 n.a. n.a. 36.415042 34.969832 -32.65018 2026-Sep-04 08:40 m 23 12 54.27 -46 22 22.8 187.743421 5.439365 n.a. n.a. 1.009935313276 -0.5365254 0.00180304278539 -0.5000502 140.6208 /L 39.3141 104.1/ 49.1414 n.a. n.a. 36.998973 34.606219 -31.80015 2026-Sep-04 08:50 m 23 13 14.67 -46 17 15.5 189.417698 5.237749 n.a. n.a. 1.009933156683 -0.5388796 0.00180105542179 -0.4909550 140.6948 /L 39.2403 104.1/ 49.0694 n.a. n.a. 37.597577 34.294515 -30.95192 2026-Sep-04 09:00 m 23 13 35.21 -46 12 02.0 191.086251 4.982211 n.a. n.a. 1.009930990633 -0.5412419 0.00179910443262 -0.4819152 140.7703 /L 39.1650 104.1/ 48.9987 n.a. n.a. 38.209462 34.033147 -30.10838 2026-Sep-04 09:10 m 23 13 55.93 -46 06 42.6 192.747251 4.673178 n.a. n.a. 1.009928815091 -0.5436124 0.00179718956030 -0.4729484 140.8471 /L 39.0884 104.1/ 48.9290 n.a. n.a. 38.833296 33.820416 -29.27228 2026-Sep-04 09:20 m 23 14 16.85 -46 01 17.2 194.398940 4.311179 n.a. n.a. 1.009926630025 -0.5459911 0.00179531047657 -0.4640723 140.9252 /L 39.0104 104.1/ 48.8606 n.a. n.a. 39.467802 33.654530 -28.44615 2026-Sep-04 09:30 m 23 14 37.99 -45 55 45.9 196.039643 3.896841 n.a. n.a. 1.009924435403 -0.5483780 0.00179346678294 -0.4553042 141.0047 /L 38.9311 104.1/ 48.7932 n.a. n.a. 40.111760 33.533628 -27.63233 2026-Sep-04 09:40 m 23 14 59.39 -45 50 08.9 197.667775 3.430885 n.a. n.a. 1.009922231191 -0.5507732 0.00179165801123 -0.4466615 141.0855 /L 38.8505 104.1/ 48.7269 n.a. n.a. 40.764008 33.455804 -26.83297 2026-Sep-04 09:50 m 23 15 21.06 -45 44 26.1 199.281854 2.914116 n.a. n.a. 1.009920017356 -0.5531766 0.00178988362427 -0.4381612 141.1675 /L 38.7687 104.0/ 48.6617 n.a. n.a. 41.423440 33.419126 -26.05002 2026-Sep-04 10:00 m 23 15 43.04 -45 38 37.8 200.880503 2.347417 n.a. n.a. 1.009917793864 -0.5555884 0.00178814301673 -0.4298203 141.2507 /L 38.6857 104.0/ 48.5975 n.a. n.a. 42.089005 33.421654 -25.28524 2026-Sep-04 10:10 m 23 16 05.34 -45 32 44.0 202.462457 1.731742 n.a. n.a. 1.009915560683 -0.5580086 0.00178643551610 -0.4216553 141.3350 /L 38.6016 104.0/ 48.5344 n.a. n.a. 42.759702 33.461452 -24.54019 2026-Sep-04 10:20 m 23 16 27.99 -45 26 44.8 204.026571 1.068111 n.a. n.a. 1.009913317779 -0.5604372 0.00178476038373 -0.4136827 141.4203 /L 38.5164 103.9/ 48.4722 n.a. n.a. 43.434583 33.536599 -23.81628 2026-Sep-04 10:30 m 23 16 51.01 -45 20 40.3 205.571812 0.357596 n.a. n.a. 1.009911065117 -0.5628742 0.00178311681612 -0.4059183 141.5067 /L 38.4301 103.9/ 48.4110 n.a. n.a. 44.112744 33.645202 -23.11470 2026-Sep-04 10:40 m 23 17 14.42 -45 14 30.8 207.097271 -0.398680 n.a. n.a. 1.009908802663 -0.5653197 0.00178150394620 -0.3983780 141.5941 /L 38.3430 103.9/ 48.3507 n.a. n.a. 44.793329 33.785401 -22.43653 >..... Elevation 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 Inquiries : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************