API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: Aug 26, 2026 Spektr-R Telescope (Spacecraft) -557 (Earth orbiting) http://www.spaceflightnow.com/news/n1107/18spektr/ BACKGROUND: Russian Earth-orbiting radio telescope funded by Russian Astro Space Center. It was launched from the Baikonur Cosmodrome on July 18, 2011 at 02:31 UTC by a Zenit-3M launcher with Fregat-SB upper stage. MISSION OBJECTIVES: The primary scientific goal of Spektr-R over the planned 5-year mission is the study of astronomical objects at an angular resolution of a few millionths of an arcsecond. This is accomplished by using the satellite interferometrically in conjunction with ground-based observatories, including Arecibo and Greenbank. The primary targets are extragalactic. Characteristics of near-Earth and interplanetary plasma will also be studied. Wavelengths used are 1.35-6.0, 18.0 and 92.0 cm. PHYSICAL DATA: Mass : 3295 kg Diameter: 10 m SPACECRAFT TRAJECTORY: Perigee: ~ 10,000 km Apogee : ~390,000 km TRAJECTORY: The IKI (Russian Space Research Institute) provided an official trajectory for Nov 1-16 (2011). TLEs are used for other times, and are low-precision, especially during the following intervals which are extrapolations over data gaps: 2011: 2012: 2013: Jul 22 - Aug 04 Feb 26 - Apr 24 Jan 16 - Jun 02 Aug 12 - Oct 04 May 11 - May 29 Jul 04 - Jul 14 Dec 09 - Feb 17 (2012) Jun 12 - Aug 30 Oct 16 - Nov 02 Sep 08 - Jan 08 (2013) Dec 24 - Jan 10 Jan 19 - Feb 22 May 09 - May 27 Trajectory name Start Stop ------------------------------ ----------------- ----------------- TLEs 2011-Jun-18 06:09 2011-Nov-01 11:01 spectr_111101_111116_111102 2011-Nov-01 11:01 2011-Nov-16 01:07 TLEs 2011-Nov-16 01:07 Current ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Mon Sep 14 14:00:10 2026 Pasadena, USA / Horizons ******************************************************************************* Target body name: Spektr-R Observatory (spacecraft) (-557) {source: spektr-r_MERGED} Center body name: Earth (399) {source: DE441} Center-site name: SATINO Remote Observatory, Haute Provence ******************************************************************************* 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 : 5.7124, 43.9320269, .703985 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 5.7124, 4601.22659, 4403.14405 {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.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-02 02:10 m 06 08 49.44 -16 21 10.7 113.388272 0.355847 n.a. n.a. 1.008923769640 -2.4407570 0.00045969135447 2.4635006 72.1675 /L 107.8081 65.5/ 74.3825 n.a. n.a. 207.00021 70.490709 64.971495 2026-Sep-02 02:20 m 06 11 01.16 -16 09 45.9 114.627791 1.781087 n.a. n.a. 1.008913999583 -2.4272230 0.00046953309700 2.4300887 71.6149 /L 108.3602 65.8/ 74.3341 n.a. n.a. 196.51509 70.246184 65.345912 2026-Sep-02 02:30 m 06 13 05.95 -15 58 47.6 115.909499 3.208182 n.a. n.a. 1.008904283767 -2.4137696 0.00047924407534 2.3984376 71.0904 /L 108.8843 66.1/ 74.2859 n.a. n.a. 186.77839 69.989731 65.718174 2026-Sep-02 02:40 m 06 15 04.31 -15 48 13.6 117.233472 4.634683 n.a. n.a. 1.008894621817 -2.4004194 0.00048883120357 2.3684673 70.5920 /L 109.3822 66.4/ 74.2380 n.a. n.a. 177.71899 69.720940 66.088394 2026-Sep-02 02:50 m 06 16 56.68 -15 38 02.3 118.600031 6.058169 n.a. n.a. 1.008885013275 -2.3871903 0.00049830108705 2.3401043 70.1179 /L 109.8558 66.7/ 74.1904 n.a. n.a. 169.27494 69.439486 66.456575 2026-Sep-02 03:00 m 06 18 43.46 -15 28 12.0 120.009716 7.476233 n.a. n.a. 1.008875457623 -2.3740962 0.00050766004584 2.3132802 69.6666 /L 110.3067 66.9/ 74.1430 n.a. n.a. 161.39206 69.145138 66.822621 2026-Sep-02 03:10 m 06 20 25.02 -15 18 41.1 121.463254 8.886460 n.a. n.a. 1.008865954291 -2.3611475 0.00051691413528 2.2879316 69.2365 /L 110.7363 67.2/ 74.0957 n.a. n.a. 154.02277 68.837760 67.186345 2026-Sep-02 03:20 Am 06 22 01.71 -15 09 28.3 122.961541 10.286418 n.a. n.a. 1.008856502675 -2.3483525 0.00052606916360 2.2639991 68.8264 /L 111.1461 67.4/ 74.0486 n.a. n.a. 147.12515 68.517320 67.547478 2026-Sep-02 03:30 Am 06 23 33.82 -15 00 32.4 124.505610 11.673641 n.a. n.a. 1.008847102141 -2.3357169 0.00053513070707 2.2414266 68.4348 /L 111.5372 67.6/ 74.0016 n.a. n.a. 140.66210 68.183892 67.905676 2026-Sep-02 03:40 Am 06 25 01.64 -14 51 52.3 126.096616 13.045620 n.a. n.a. 1.008837752037 -2.3232450 0.00054410412328 2.2201613 68.0608 /L 111.9109 67.8/ 73.9546 n.a. n.a. 134.60071 67.837669 68.260533 2026-Sep-02 03:50 Am 06 26 25.45 -14 43 26.8 127.735806 14.399794 n.a. n.a. 1.008828451695 -2.3109393 0.00055299456248 2.2001530 67.7032 /L 112.2681 68.0/ 73.9076 n.a. n.a. 128.91162 67.478962 68.611582 2026-Sep-02 04:00 Nm 06 27 45.47 -14 35 15.1 129.424494 15.733536 n.a. n.a. 1.008819200442 -2.2988016 0.00056180697728 2.1813535 67.3610 /L 112.6099 68.2/ 73.8606 n.a. n.a. 123.56862 67.108215 68.958309 2026-Sep-02 04:10 Nm 06 29 01.94 -14 27 16.2 131.164036 17.044153 n.a. n.a. 1.008809997599 -2.2868325 0.00057054613111 2.1637169 67.0334 /L 112.9371 68.4/ 73.8136 n.a. n.a. 118.54815 66.726011 69.300161 2026-Sep-02 04:20 Nm 06 30 15.07 -14 19 29.4 132.955798 18.328872 n.a. n.a. 1.008800842485 -2.2750317 0.00057921660547 2.1471986 66.7194 /L 113.2507 68.5/ 73.7664 n.a. n.a. 113.82901 66.333077 69.636553 2026-Sep-02 04:30 Nm 06 31 25.06 -14 11 53.8 134.801123 19.584845 n.a. n.a. 1.008791734424 -2.2633985 0.00058782280599 2.1317555 66.4183 /L 113.5514 68.7/ 73.7191 n.a. n.a. 109.39205 65.930289 69.966876 2026-Sep-02 04:40 Cm 06 32 32.09 -14 04 28.9 136.701297 20.809140 n.a. n.a. 1.008782672742 -2.2519315 0.00059636896780 2.1173460 66.1293 /L 113.8400 68.8/ 73.6716 n.a. n.a. 105.21986 65.518682 70.290506 2026-Sep-02 04:50 Cm 06 33 36.34 -13 57 13.9 138.657508 21.998742 n.a. n.a. 1.008773656772 -2.2406292 0.00060485915998 2.1039291 65.8517 /L 114.1173 68.9/ 73.6239 n.a. n.a. 101.29661 65.099452 70.606813 >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2026-Sep-03 03:10 m 07 48 02.17 -06 59 47.9 100.733021 0.923841 n.a. n.a. 1.007822596631 -1.4495956 0.00145829793096 0.7833921 47.0255 /L 132.9139 71.3/ 63.5148 n.a. n.a. 20.865204 73.899107 64.849247 2026-Sep-03 03:20 m 07 48 15.28 -06 58 49.2 102.434068 2.665144 n.a. n.a. 1.007816781646 -1.4461535 0.00146144949166 0.7811086 46.9741 /L 132.9652 71.2/ 63.4615 n.a. n.a. 19.998765 73.215555 65.662359 2026-Sep-03 03:30 Am 07 48 27.80 -06 57 50.6 104.150900 4.396916 n.a. n.a. 1.007810980420 -1.4427283 0.00146459306986 0.7794399 46.9251 /L 133.0141 71.2/ 63.4086 n.a. n.a. 19.148568 72.469488 66.493857 2026-Sep-03 03:40 Am 07 48 39.72 -06 56 52.1 105.886626 6.117455 n.a. n.a. 1.007805192887 -1.4393199 0.00146773112488 0.7783825 46.8784 /L 133.0607 71.2/ 63.3559 n.a. n.a. 18.316256 71.655637 67.339854 2026-Sep-03 03:50 Am 07 48 51.07 -06 55 53.6 107.644381 7.824990 n.a. n.a. 1.007799418979 -1.4359281 0.00147086609958 0.7779318 46.8340 /L 133.1050 71.2/ 63.3036 n.a. n.a. 17.503494 70.768380 68.196140 2026-Sep-03 04:00 Nm 07 49 01.84 -06 54 55.1 109.427333 9.517670 n.a. n.a. 1.007793658631 -1.4325526 0.00147400041572 0.7780818 46.7919 /L 133.1471 71.2/ 63.2514 n.a. n.a. 16.711966 69.801785 69.058224 2026-Sep-03 04:10 Nm 07 49 12.05 -06 53 56.5 111.238685 11.193554 n.a. n.a. 1.007787911778 -1.4291934 0.00147713646932 0.7788257 46.7520 /L 133.1869 71.1/ 63.1995 n.a. n.a. 15.943377 68.749661 69.921381 2026-Sep-03 04:20 Nm 07 49 21.72 -06 52 57.9 113.081680 12.850601 n.a. n.a. 1.007782178356 -1.4258501 0.00148027662612 0.7801553 46.7142 /L 133.2246 71.1/ 63.1476 n.a. n.a. 15.199440 67.605663 70.780712 2026-Sep-03 04:30 Nm 07 49 30.85 -06 51 59.1 114.959596 14.486662 n.a. n.a. 1.007776458300 -1.4225227 0.00148342321685 0.7820612 46.6785 /L 133.2602 71.1/ 63.0959 n.a. n.a. 14.481878 66.363428 71.631214 2026-Sep-03 04:40 Cm 07 49 39.46 -06 51 00.2 116.875742 16.099465 n.a. n.a. 1.007770751548 -1.4192109 0.00148657853282 0.7845332 46.6449 /L 133.2938 71.1/ 63.0442 n.a. n.a. 13.792410 65.016775 72.467846 2026-Sep-03 04:50 Cm 07 49 47.56 -06 50 01.1 118.833453 17.686611 n.a. n.a. 1.007765058037 -1.4159147 0.00148974482126 0.7875596 46.6132 /L 133.3253 71.0/ 62.9925 n.a. n.a. 13.132740 63.559971 73.285615 >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2026-Sep-04 03:20 r 08 15 03.77 -04 37 52.2 96.778957 0.238547 n.a. n.a. 1.007098919508 -1.0661733 0.00195125496185 0.2951736 40.6656 /L 139.2621 63.5/ 52.0416 n.a. n.a. 12.203060 74.740722 45.720296 2026-Sep-04 03:30 Am 08 15 11.44 -04 37 19.1 98.494278 2.011339 n.a. n.a. 1.007094640146 -1.0640568 0.00195244293513 0.2940891 40.6377 /L 139.2899 63.5/ 51.9841 n.a. n.a. 11.595624 73.916999 47.058543 2026-Sep-04 03:40 Am 08 15 18.69 -04 36 46.0 100.220846 3.777501 n.a. n.a. 1.007090369279 -1.0619450 0.00195362774954 0.2936228 40.6116 /L 139.3161 63.4/ 51.9272 n.a. n.a. 10.995881 72.998862 48.510166 2026-Sep-04 03:50 Am 08 15 25.52 -04 36 12.9 101.961938 5.535358 n.a. n.a. 1.007086106888 -1.0598378 0.00195481187946 0.2937720 40.5870 /L 139.3406 63.4/ 51.8708 n.a. n.a. 10.405372 71.973877 50.070914 2026-Sep-04 04:00 Nm 08 15 31.95 -04 35 39.7 103.720860 7.283176 n.a. n.a. 1.007081852955 -1.0577352 0.00195599778623 0.2945329 40.5642 /L 139.3635 63.3/ 51.8149 n.a. n.a. 9.8257094 70.827699 51.733659 2026-Sep-04 04:10 Nm 08 15 37.96 -04 35 06.5 105.500955 9.019158 n.a. n.a. 1.007077607462 -1.0556372 0.00195718791343 0.2959004 40.5429 /L 139.3847 63.3/ 51.7594 n.a. n.a. 9.2585909 69.543810 53.488066 2026-Sep-04 04:20 Nm 08 15 43.57 -04 34 33.2 107.305612 10.741428 n.a. n.a. 1.007073370391 -1.0535438 0.00195838468218 0.2978685 40.5232 /L 139.4044 63.3/ 51.7043 n.a. n.a. 8.7058141 68.103244 55.320385 2026-Sep-04 04:30 Nm 08 15 48.79 -04 33 59.8 109.138272 12.448020 n.a. n.a. 1.007069141723 -1.0514548 0.00195959048639 0.3004296 40.5051 /L 139.4225 63.2/ 51.6496 n.a. n.a. 8.1692931 66.484337 57.213410 2026-Sep-04 04:40 Cm 08 15 53.61 -04 33 26.2 111.002431 14.136872 n.a. n.a. 1.007064921441 -1.0493703 0.00196080768815 0.3035754 40.4885 /L 139.4390 63.2/ 51.5951 n.a. n.a. 7.6510772 64.662558 59.146645 2026-Sep-04 04:50 Cm 08 15 58.06 -04 32 52.5 112.901643 15.805807 n.a. n.a. 1.007060709526 -1.0472903 0.00196203861300 0.3072960 40.4734 /L 139.4541 63.1/ 51.5409 n.a. n.a. 7.1533717 62.610501 61.096712 >..... Daylight Cut-off Requested .....< >..... 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 ***************************************************************************************************************************************************************************************************************************************************