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 14:25:58 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: 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: 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 10:30 m 07 09 45.70 -10 21 57.1 102.878085 -0.409225 n.a. n.a. 1.008490239971 -1.9354877 0.00089691078645 1.4464312 56.5388 /L 123.4189 72.3/ 70.8607 n.a. n.a. 55.358529 73.748149 67.464154 2026-Sep-02 10:40 m 07 10 20.85 -10 19 21.1 104.293122 1.431838 n.a. n.a. 1.008482485362 -1.9283134 0.00090271426713 1.4372357 56.3935 /L 123.5640 72.4/ 70.8125 n.a. n.a. 53.299660 73.291539 67.968213 2026-Sep-02 10:50 m 07 10 54.60 -10 16 46.8 105.728256 3.265901 n.a. n.a. 1.008474759362 -1.9212171 0.00090848227587 1.4287860 56.2538 /L 123.7034 72.4/ 70.7646 n.a. n.a. 51.299419 72.801362 68.481096 2026-Sep-02 11:00 m 07 11 26.98 -10 14 14.0 107.186330 5.091512 n.a. n.a. 1.008467061661 -1.9141972 0.00091421779831 1.4210784 56.1197 /L 123.8374 72.5/ 70.7171 n.a. n.a. 49.358383 72.275956 69.001292 2026-Sep-02 11:10 m 07 11 58.03 -10 11 42.6 108.670265 6.907141 n.a. n.a. 1.008459391955 -1.9072522 0.00091992380386 1.4141085 55.9908 /L 123.9660 72.5/ 70.6698 n.a. n.a. 47.477191 71.713673 69.527171 2026-Sep-02 11:20 m 07 12 27.78 -10 09 12.5 110.183068 8.711165 n.a. n.a. 1.008451749945 -1.9003805 0.00092560324104 1.4078705 55.8671 /L 124.0895 72.6/ 70.6227 n.a. n.a. 45.656525 71.112912 70.056994 2026-Sep-02 11:30 m 07 12 56.28 -10 06 43.6 111.727843 10.501862 n.a. n.a. 1.008444135341 -1.8935807 0.00093125903303 1.4023574 55.7485 /L 124.2080 72.6/ 70.5759 n.a. n.a. 43.897104 70.472153 70.588925 2026-Sep-02 11:40 Am 07 13 23.55 -10 04 15.8 113.307797 12.277397 n.a. n.a. 1.008436547857 -1.8868512 0.00093689407294 1.3975612 55.6347 /L 124.3216 72.7/ 70.5292 n.a. n.a. 42.199663 69.789999 71.121047 2026-Sep-02 11:50 Am 07 13 49.64 -10 01 48.9 114.926248 14.035815 n.a. n.a. 1.008428987211 -1.8801908 0.00094251121918 1.3934728 55.5255 /L 124.4305 72.7/ 70.4826 n.a. n.a. 40.564944 69.065226 71.651379 2026-Sep-02 12:00 Am 07 14 14.59 -09 59 22.8 116.586624 15.775023 n.a. n.a. 1.008421453130 -1.8735981 0.00094811329073 1.3900816 55.4210 /L 124.5348 72.7/ 70.4360 n.a. n.a. 38.993678 68.296846 72.177896 2026-Sep-02 12:10 Nm 07 14 38.44 -09 56 57.4 118.292466 17.492783 n.a. n.a. 1.008413945345 -1.8670717 0.00095370306240 1.3873761 55.3208 /L 124.6348 72.8/ 70.3894 n.a. n.a. 37.486567 67.484175 72.698552 2026-Sep-02 12:20 Nm 07 15 01.21 -09 54 32.7 120.047424 19.186698 n.a. n.a. 1.008406463591 -1.8606103 0.00095928326019 1.3853435 55.2248 /L 124.7306 72.8/ 70.3428 n.a. n.a. 36.044271 66.626905 73.211300 2026-Sep-02 12:30 Nm 07 15 22.97 -09 52 08.6 121.855247 20.854196 n.a. n.a. 1.008399007610 -1.8542127 0.00096485655648 1.3839700 55.1329 /L 124.8223 72.8/ 70.2962 n.a. n.a. 34.667383 65.725198 73.714120 2026-Sep-02 12:40 Cm 07 15 43.73 -09 49 44.9 123.719769 22.492523 n.a. n.a. 1.008391577148 -1.8478777 0.00097042556549 1.3832404 55.0449 /L 124.9101 72.8/ 70.2493 n.a. n.a. 33.356411 64.779772 74.205041 2026-Sep-02 12:50 Cm 07 16 03.55 -09 47 21.7 125.644883 24.098723 n.a. n.a. 1.008384171956 -1.8416040 0.00097599283857 1.3831385 54.9606 /L 124.9942 72.8/ 70.2024 n.a. n.a. 32.111758 63.791998 74.682169 >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2026-Sep-03 11:10 m 07 59 11.47 -05 55 28.2 98.583442 1.269883 n.a. n.a. 1.007557963460 -1.3006825 0.00165275740339 0.5574147 44.3119 /L 135.6225 69.1/ 59.7379 n.a. n.a. 16.315518 75.016738 59.681625 2026-Sep-03 11:20 m 07 59 21.73 -05 54 45.2 100.094740 3.199967 n.a. n.a. 1.007552744125 -1.2978808 0.00165500133596 0.5558485 44.2730 /L 135.6613 69.1/ 59.6852 n.a. n.a. 15.507704 74.224087 60.831880 2026-Sep-03 11:30 m 07 59 31.44 -05 54 02.2 101.621882 5.122855 n.a. n.a. 1.007547536005 -1.2950894 0.00165724028492 0.5549574 44.2364 /L 135.6979 69.1/ 59.6331 n.a. n.a. 14.712510 73.341357 62.027345 2026-Sep-03 11:40 Am 07 59 40.59 -05 53 19.2 103.168353 7.037048 n.a. n.a. 1.007542339060 -1.2923082 0.00165947695199 0.5547382 44.2019 /L 135.7324 69.1/ 59.5813 n.a. n.a. 13.931824 72.357288 63.261373 2026-Sep-03 11:50 Am 07 59 49.20 -05 52 36.1 104.737712 8.940970 n.a. n.a. 1.007537153248 -1.2895373 0.00166171402390 0.5551867 44.1695 /L 135.7647 69.0/ 59.5300 n.a. n.a. 13.167613 71.259040 64.526239 2026-Sep-03 12:00 Am 07 59 57.27 -05 51 53.0 106.333615 10.832959 n.a. n.a. 1.007531978529 -1.2867764 0.00166395416722 0.5562971 44.1393 /L 135.7948 69.0/ 59.4789 n.a. n.a. 12.421935 70.032009 65.813196 2026-Sep-03 12:10 Nm 08 00 04.82 -05 51 09.8 107.959827 12.711253 n.a. n.a. 1.007526814863 -1.2840254 0.00166620002318 0.5580625 44.1111 /L 135.8229 69.0/ 59.4282 n.a. n.a. 11.696953 68.659662 67.112568 2026-Sep-03 12:20 Nm 08 00 11.84 -05 50 26.4 109.620243 14.573972 n.a. n.a. 1.007521662211 -1.2812844 0.00166845420254 0.5604746 44.0850 /L 135.8490 68.9/ 59.3776 n.a. n.a. 10.994950 67.123413 68.413879 2026-Sep-03 12:30 Nm 08 00 18.37 -05 49 42.8 111.318893 16.419108 n.a. n.a. 1.007516520533 -1.2785532 0.00167071928041 0.5635239 44.0609 /L 135.8731 68.9/ 59.3273 n.a. n.a. 10.318344 65.402589 69.706014 2026-Sep-03 12:40 Cm 08 00 24.39 -05 48 59.0 113.059960 18.244509 n.a. n.a. 1.007511389791 -1.2758316 0.00167299779121 0.5671996 44.0387 /L 135.8952 68.9/ 59.2771 n.a. n.a. 9.6697008 63.474559 70.977407 2026-Sep-03 12:50 Cm 08 00 29.93 -05 48 15.0 114.847785 20.047858 n.a. n.a. 1.007506269945 -1.2731197 0.00167529222343 0.5714897 44.0184 /L 135.9154 68.8/ 59.2269 n.a. n.a. 9.0517499 61.315118 72.216255 2026-Sep-03 13:00 Cm 08 00 35.01 -05 47 30.7 116.686870 21.826659 n.a. n.a. 1.007501160958 -1.2704173 0.00167760501477 0.5763809 43.9999 /L 135.9338 68.8/ 59.1768 n.a. n.a. 8.4673818 58.899290 73.410750 >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2026-Sep-04 11:20 m 08 21 58.84 -03 58 22.3 95.699716 0.730694 n.a. n.a. 1.006902795924 -0.9693134 0.00205997216079 0.1444895 39.0790 /L 140.8471 60.4/ 48.1181 n.a. n.a. 10.987270 75.149434 27.836882 2026-Sep-04 11:30 m 08 22 05.73 -03 57 53.1 97.216789 2.682901 n.a. n.a. 1.006898905507 -0.9673870 0.00206055399701 0.1435987 39.0546 /L 140.8715 60.3/ 48.0619 n.a. n.a. 10.362016 74.218428 29.088153 2026-Sep-04 11:40 Am 08 22 12.19 -03 57 23.8 98.745804 4.630007 n.a. n.a. 1.006895022828 -0.9654640 0.00206113358321 0.1433883 39.0319 /L 140.8942 60.3/ 48.0063 n.a. n.a. 9.7439954 73.163810 30.565215 2026-Sep-04 11:50 Am 08 22 18.23 -03 56 54.5 100.290332 6.570552 n.a. n.a. 1.006891147875 -0.9635442 0.00206171364371 0.1438558 39.0109 /L 140.9152 60.3/ 47.9514 n.a. n.a. 9.1349867 71.965132 32.286061 2026-Sep-04 12:00 Am 08 22 23.83 -03 56 25.1 101.854019 8.503013 n.a. n.a. 1.006887280634 -0.9616277 0.00206229689021 0.1449974 38.9916 /L 140.9346 60.2/ 47.8971 n.a. n.a. 8.5369071 70.597729 34.265708 2026-Sep-04 12:10 Nm 08 22 29.02 -03 55 55.6 103.440600 10.425797 n.a. n.a. 1.006883421092 -0.9597144 0.00206288601655 0.1468081 38.9739 /L 140.9522 60.2/ 47.8433 n.a. n.a. 7.9518467 69.031773 36.513686 2026-Sep-04 12:20 Nm 08 22 33.79 -03 55 26.0 105.053923 12.337221 n.a. n.a. 1.006879569237 -0.9578043 0.00206348369357 0.1492813 38.9579 /L 140.9682 60.1/ 47.7900 n.a. n.a. 7.3821144 67.231157 39.030811 2026-Sep-04 12:30 Nm 08 22 38.14 -03 54 56.4 106.697967 14.235501 n.a. n.a. 1.006875725056 -0.9558974 0.00206409256383 0.1524095 38.9436 /L 140.9826 60.1/ 47.7372 n.a. n.a. 6.8302965 65.152243 41.805409 2026-Sep-04 12:40 Nm 08 22 42.10 -03 54 26.6 108.376861 16.118736 n.a. n.a. 1.006871888535 -0.9539936 0.00206471523647 0.1561836 38.9308 /L 140.9954 60.0/ 47.6848 n.a. n.a. 6.2993325 62.742579 44.809452 2026-Sep-04 12:50 Cm 08 22 45.66 -03 53 56.6 110.094898 17.984893 n.a. n.a. 1.006868059663 -0.9520930 0.00206535428193 0.1605934 38.9196 /L 141.0066 60.0/ 47.6327 n.a. n.a. 5.7926064 59.939879 47.995447 2026-Sep-04 13:00 Cm 08 22 48.83 -03 53 26.5 111.856554 19.831786 n.a. n.a. 1.006864238427 -0.9501956 0.00206601222694 0.1656273 38.9099 /L 141.0163 59.9/ 47.5809 n.a. n.a. 5.3140540 56.671831 51.295160 >..... 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 ***************************************************************************************************************************************************************************************************************************************************