API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: Dec 06, 2024 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 Thu Dec 12 03:55:30 2024 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., Siding Spring ******************************************************************************* Start time : A.D. 2024-Nov-30 00:00:00.0000 UT Stop time : A.D. 2024-Dec-01 00:00:00.0000 UT Step-size : 10 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 149.0644, -31.2733577, 1.16499 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 149.0644,5457.31536,-3292.4397 {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.241211.p250309 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-DEC-11. PREDICTS-> 2025-MAR-08 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 .....< 2024-Nov-30 15:20 09 15 34.57 +46 09 32.5 32.252683 0.312817 n.a. n.a. 0.987279128642 -0.3589087 0.00232764337927 -0.0514800 117.7222 /L 62.1582 113.6/ 0.4553 n.a. n.a. 5.1300863 196.53167 -19.62678 2024-Nov-30 15:30 09 15 32.94 +46 08 41.8 30.928579 1.449090 n.a. n.a. 0.987277693851 -0.3596927 0.00232746054952 -0.0454461 117.7321 /L 62.1483 113.7/ 0.4443 n.a. n.a. 5.5558653 200.28515 -16.20941 2024-Nov-30 15:40 09 15 30.87 +46 07 48.0 29.567089 2.543898 n.a. n.a. 0.987276255928 -0.3604760 0.00232730270529 -0.0390098 117.7432 /L 62.1372 113.8/ 0.4336 n.a. n.a. 6.0080115 203.27773 -12.99436 2024-Nov-30 15:50 09 15 28.39 +46 06 51.1 28.168530 3.595384 n.a. n.a. 0.987274814875 -0.3612586 0.00232717143173 -0.0321856 117.7555 /L 62.1250 114.0/ 0.4231 n.a. n.a. 6.4783270 205.63911 -10.01388 2024-Nov-30 16:00 09 15 25.50 +46 05 50.9 26.733342 4.601677 n.a. n.a. 0.987273370697 -0.3620405 0.00232706825392 -0.0249888 117.7689 /L 62.1116 114.1/ 0.4129 n.a. n.a. 6.9605233 207.48080 -7.271340 2024-Nov-30 16:10 09 15 22.23 +46 04 47.3 25.262108 5.560904 n.a. n.a. 0.987271923394 -0.3628218 0.00232699463388 -0.0174357 117.7833 /L 62.0972 114.2/ 0.4030 n.a. n.a. 7.4497710 208.89471 -4.754567 2024-Nov-30 16:20 09 15 18.60 +46 03 40.1 23.755563 6.471194 n.a. n.a. 0.987270472972 -0.3636024 0.00232695196741 -0.0095432 117.7987 /L 62.0818 114.3/ 0.3934 n.a. n.a. 7.9423350 209.95503 -2.444303 2024-Nov-30 16:30 09 15 14.63 +46 02 29.3 22.214614 7.330691 n.a. n.a. 0.987269019431 -0.3643824 0.00232694158107 -0.0013287 117.8150 /L 62.0655 114.4/ 0.3840 n.a. n.a. 8.4352986 210.72118 -0.319152 2024-Nov-30 16:40 09 15 10.34 +46 01 14.8 20.640348 8.137569 n.a. n.a. 0.987267562776 -0.3651618 0.00232696472948 0.0071894 117.8322 /L 62.0483 114.5/ 0.3750 n.a. n.a. 8.9263597 211.24063 1.6418022 2024-Nov-30 16:50 09 15 05.76 +45 59 56.3 19.034042 8.890041 n.a. n.a. 0.987266103009 -0.3659405 0.00232702259252 0.0159920 117.8502 /L 62.0303 114.6/ 0.3662 n.a. n.a. 9.4136830 211.55142 3.4577625 2024-Nov-30 17:00 09 15 00.91 +45 58 33.9 17.397174 9.586375 n.a. n.a. 0.987264640133 -0.3667185 0.00232711627280 0.0250598 117.8690 /L 62.0116 114.7/ 0.3577 n.a. n.a. 9.8957927 211.68416 5.1457545 2024-Nov-30 17:10 09 14 55.81 +45 57 07.5 15.731422 10.224907 n.a. n.a. 0.987263174150 -0.3674960 0.00232724679328 0.0343724 117.8884 /L 61.9923 114.8/ 0.3494 n.a. n.a. 10.371495 211.66360 6.7205709 2024-Nov-30 17:20 A 09 14 50.50 +45 55 37.0 14.038672 10.804057 n.a. n.a. 0.987261705063 -0.3682728 0.00232741509507 0.0439093 117.9083 /L 61.9723 114.9/ 0.3415 n.a. n.a. 10.839818 211.50992 8.1949104 2024-Nov-30 17:30 A 09 14 44.98 +45 54 02.3 12.321013 11.322344 n.a. n.a. 0.987260232875 -0.3690490 0.00232762203526 0.0536492 117.9288 /L 61.9518 115.0/ 0.3338 n.a. n.a. 11.299976 211.23968 9.5795971 2024-Nov-30 17:40 A 09 14 39.30 +45 52 23.3 10.580730 11.778398 n.a. n.a. 0.987258757589 -0.3698246 0.00232786838506 0.0635706 117.9498 /L 61.9309 115.1/ 0.3264 n.a. n.a. 11.751328 210.86653 10.883820 2024-Nov-30 17:50 A 09 14 33.47 +45 50 40.1 8.820296 12.170981 n.a. n.a. 0.987257279207 -0.3705996 0.00232815482814 0.0736513 117.9710 /L 61.9096 115.2/ 0.3192 n.a. n.a. 12.193364 210.40184 12.115365 2024-Nov-30 18:00 N 09 14 27.52 +45 48 52.6 7.042355 12.498993 n.a. n.a. 0.987255797732 -0.3713740 0.00232848195897 0.0838689 117.9926 /L 61.8880 115.4/ 0.3123 n.a. n.a. 12.625680 209.85514 13.280817 2024-Nov-30 18:10 N 09 14 21.48 +45 47 00.7 5.249709 12.761491 n.a. n.a. 0.987254313167 -0.3721479 0.00232885028152 0.0942008 118.0144 /L 61.8663 115.5/ 0.3057 n.a. n.a. 13.047967 209.23444 14.385751 2024-Nov-30 18:20 Nm 09 14 15.38 +45 45 04.4 3.445291 12.957697 n.a. n.a. 0.987252825513 -0.3729211 0.00232926020806 0.1046240 118.0364 /L 61.8443 115.6/ 0.2994 n.a. n.a. 13.459996 208.54656 15.434879 2024-Nov-30 18:30 Cm 09 14 09.23 +45 43 03.8 1.632140 13.087006 n.a. n.a. 0.987251334775 -0.3736938 0.00232971205822 0.1151152 118.0584 /L 61.8223 115.7/ 0.2933 n.a. n.a. 13.861616 207.79735 16.432188 2024-Nov-30 18:40 Ct 09 14 03.07 +45 40 58.7 359.813377 13.148999 n.a. n.a. 0.987249840954 -0.3744659 0.00233020605814 0.1256510 118.0803 /L 61.8004 115.8/ 0.2874 n.a. n.a. 14.252740 206.99182 17.381047 >..... 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/hrzn_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************