API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: Dec 06, 2024 Chandra Spacecraft (X-ray observatory) / (Earth) -151 http://xrtpub.harvard.edu/index.html Chandra X-ray Observatory: Deployment (STS-93) = July 23, 1999 Data storage = 1.8 gbs Science mission = ~5 years Length (sun shade open) = 45.3 m Orbital check-out = 2 months Length (sun shade clsd) = 38.7 m ORBITAL DATA: Inclination = 28.5 degrees Orbital period = ~64 hours Apogee altitude = ~ 86,487 km Observing time / orbit = ~55 hours Perigee altitude = ~ 5,999 km WEIGHTS & PROPULSION: Dry = 10,560 lbs Propellant = 2,153 lbs Pressurant = 10 lb Total launch weight = 12,930 lb Engines = 4 Thrust per engine = 105 lb SPACECRAFT TRAJECTORY (from CFA): Trajectory after 2024-Dec-03 is a prediction Trajectory name Start Stop ---------------------------- ----------- ----------- cxo_99219_06045 1999-Aug-07 2006-Feb-14 cxo_06002_10103 2006-Feb-03 2010-Feb-25 CXO_10056_25126 2010-Feb-25 2025-Jun-04 ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Thu Dec 12 02:49:42 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: Chandra Observatory (spacecraft) (-151) {source: chandra_merged} Center body name: Earth (399) {source: chandra_merged} Center-site name: iTelescope Obs.,Beryl Junc. (Sato) ******************************************************************************* 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 : 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: chandra_merged} Rel. light bend : Sun {source: chandra_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.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 >..... Daylight Cut-off Requested .....< 2024-Nov-30 00:30 C 16 45 39.77 +41 20 42.0 297.849257 36.283667 n.a. n.a. 0.985934958617 -0.8801399 0.00075068810916 1.4008998 63.1646 /T 116.7967 67.4/ 1.7904 n.a. n.a. 85.067392 120.99754 61.143286 2024-Nov-30 00:40 C 16 46 44.51 +41 13 21.8 298.484653 34.678656 n.a. n.a. 0.985931443661 -0.8726484 0.00075628513611 1.3901124 63.0633 /T 116.8978 67.3/ 1.7729 n.a. n.a. 85.376896 120.83886 60.685917 2024-Nov-30 00:50 N 16 47 49.48 +41 06 02.2 299.146321 33.081763 n.a. n.a. 0.985927958587 -0.8652388 0.00076183851583 1.3791311 62.9632 /T 116.9976 67.3/ 1.7552 n.a. n.a. 85.685992 120.65597 60.222304 2024-Nov-30 01:00 N 16 48 54.70 +40 58 43.5 299.833675 31.493683 n.a. n.a. 0.985924503070 -0.8579088 0.00076734744597 1.3679438 62.8646 /T 117.0960 67.2/ 1.7374 n.a. n.a. 85.993202 120.45052 59.752540 2024-Nov-30 01:10 N 16 50 00.17 +40 51 26.1 300.546270 29.915120 n.a. n.a. 0.985921076795 -0.8506561 0.00077281107614 1.3565386 62.7674 /T 117.1929 67.2/ 1.7193 n.a. n.a. 86.297147 120.22410 59.276699 2024-Nov-30 01:20 A 16 51 05.91 +40 44 10.2 301.283777 28.346785 n.a. n.a. 0.985917679458 -0.8434786 0.00077822851127 1.3449050 62.6719 /T 117.2881 67.2/ 1.7011 n.a. n.a. 86.596536 119.97823 58.794836 2024-Nov-30 01:30 A 16 52 11.93 +40 36 56.1 302.045973 26.789404 n.a. n.a. 0.985914310761 -0.8363742 0.00078359881487 1.3330331 62.5781 /T 117.3817 67.1/ 1.6826 n.a. n.a. 86.890159 119.71435 58.306991 2024-Nov-30 01:40 A 16 53 18.23 +40 29 44.2 302.832732 25.243718 n.a. n.a. 0.985910970414 -0.8293408 0.00078892101235 1.3209136 62.4861 /T 117.4734 67.1/ 1.6640 n.a. n.a. 87.176875 119.43384 57.813189 2024-Nov-30 01:50 16 54 24.82 +40 22 34.7 303.644011 23.710483 n.a. n.a. 0.985907658136 -0.8223766 0.00079419409434 1.3085385 62.3961 /T 117.5632 67.0/ 1.6452 n.a. n.a. 87.455610 119.13803 57.313441 2024-Nov-30 02:00 16 55 31.69 +40 15 27.9 304.479840 22.190475 n.a. n.a. 0.985904373655 -0.8154797 0.00079941701996 1.2959002 62.3081 /T 117.6509 67.0/ 1.6263 n.a. n.a. 87.725346 118.82818 56.807750 2024-Nov-30 02:10 16 56 38.86 +40 08 24.0 305.340319 20.684491 n.a. n.a. 0.985901116704 -0.8086482 0.00080458872010 1.2829920 62.2222 /T 117.7366 66.9/ 1.6073 n.a. n.a. 87.985118 118.50545 56.296106 2024-Nov-30 02:20 16 57 46.32 +40 01 23.3 306.225607 19.193347 n.a. n.a. 0.985897887023 -0.8018804 0.00080970810072 1.2698083 62.1386 /T 117.8200 66.9/ 1.5881 n.a. n.a. 88.234009 118.17100 55.778490 2024-Nov-30 02:30 16 58 54.06 +39 54 26.1 307.135916 17.717886 n.a. n.a. 0.985894684361 -0.7951746 0.00081477404602 1.2563439 62.0572 /T 117.9011 66.9/ 1.5687 n.a. n.a. 88.471144 117.82588 55.254878 2024-Nov-30 02:40 17 00 02.09 +39 47 32.6 308.071503 16.258975 n.a. n.a. 0.985891508472 -0.7885292 0.00081978542172 1.2425947 61.9782 /T 117.9799 66.8/ 1.5493 n.a. n.a. 88.695686 117.47110 54.725238 2024-Nov-30 02:50 17 01 10.39 +39 40 43.0 309.032668 14.817509 n.a. n.a. 0.985888359118 -0.7819425 0.00082474107823 1.2285572 61.9017 /T 118.0562 66.8/ 1.5298 n.a. n.a. 88.906836 117.10761 54.189531 2024-Nov-30 03:00 17 02 18.97 +39 33 57.5 310.019746 13.394411 n.a. n.a. 0.985885236066 -0.7754132 0.00082963985382 1.2142288 61.8277 /T 118.1300 66.8/ 1.5102 n.a. n.a. 89.103825 116.73631 53.647714 2024-Nov-30 03:10 17 03 27.81 +39 27 16.4 311.033102 11.990634 n.a. n.a. 0.985882139089 -0.7689396 0.00083448057771 1.1996077 61.7563 /T 118.2012 66.7/ 1.4905 n.a. n.a. 89.285916 116.35805 53.099739 2024-Nov-30 03:20 17 04 36.91 +39 20 39.8 312.073121 10.607163 n.a. n.a. 0.985879067966 -0.7625203 0.00083926207322 1.1846927 61.6876 /T 118.2697 66.7/ 1.4707 n.a. n.a. 89.452399 115.97362 52.545556 2024-Nov-30 03:30 17 05 46.25 +39 14 08.0 313.140212 9.245014 n.a. n.a. 0.985876022482 -0.7561540 0.00084398316079 1.1694835 61.6216 /T 118.3355 66.7/ 1.4509 n.a. n.a. 89.602590 115.58376 51.985109 2024-Nov-30 03:40 17 06 55.82 +39 07 41.0 314.234791 7.905237 n.a. n.a. 0.985873002428 -0.7498392 0.00084864266099 1.1539805 61.5584 /T 118.3984 66.7/ 1.4311 n.a. n.a. 89.735829 115.18917 51.418340 2024-Nov-30 03:50 17 08 05.61 +39 01 19.1 315.357283 6.588917 n.a. n.a. 0.985870007600 -0.7435747 0.00085323939750 1.1381849 61.4980 /T 118.4586 66.6/ 1.4112 n.a. n.a. 89.851481 114.79052 50.845190 2024-Nov-30 04:00 17 09 15.60 +38 55 02.5 316.508109 5.297173 n.a. n.a. 0.985867037797 -0.7373592 0.00085777220002 1.1220985 61.4405 /T 118.5159 66.6/ 1.3913 n.a. n.a. 89.948930 114.38841 50.265596 2024-Nov-30 04:10 17 10 25.79 +38 48 51.3 317.687687 4.031161 n.a. n.a. 0.985864092828 -0.7311915 0.00086223990715 1.1057238 61.3860 /T 118.5702 66.6/ 1.3714 n.a. n.a. 90.027585 113.98341 49.679492 2024-Nov-30 04:20 17 11 36.16 +38 42 45.6 318.896416 2.792069 n.a. n.a. 0.985861172501 -0.7250703 0.00086664136920 1.0890642 61.3344 /T 118.6216 66.6/ 1.3516 n.a. n.a. 90.086870 113.57608 49.086812 2024-Nov-30 04:30 17 12 46.68 +38 36 45.6 320.134674 1.581123 n.a. n.a. 0.985858276633 -0.7189945 0.00087097545094 1.0721236 61.2859 /T 118.6699 66.6/ 1.3317 n.a. n.a. 90.126235 113.16689 48.487489 2024-Nov-30 04:40 17 13 57.35 +38 30 51.4 321.402808 0.399583 n.a. n.a. 0.985855405044 -0.7129630 0.00087524103435 1.0549067 61.2404 /T 118.7152 66.6/ 1.3119 n.a. n.a. 90.145144 112.75633 47.881450 >..... Elevation Cut-off Requested .....< 2024-Nov-30 12:50 18 06 51.93 +35 49 31.8 42.696944 0.390609 n.a. n.a. 0.985741661572 -0.4542200 0.00098769177707 0.0984445 62.2118 /T 117.7374 68.6/ 0.5853 n.a. n.a. 60.526838 96.421405 7.7522105 2024-Nov-30 13:00 A 18 07 40.88 +35 48 23.6 44.095521 1.628123 n.a. n.a. 0.985739849434 -0.4494220 0.00098805484859 0.0826659 62.2668 /T 117.6824 68.6/ 0.5774 n.a. n.a. 59.329233 96.288668 6.6486757 2024-Nov-30 13:10 A 18 08 28.85 +35 47 18.1 45.468544 2.900364 n.a. n.a. 0.985738056518 -0.4446349 0.00098835542325 0.0672823 62.3215 /T 117.6276 68.7/ 0.5697 n.a. n.a. 58.116611 96.174740 5.5293976 2024-Nov-30 13:20 A 18 09 15.82 +35 46 15.0 46.816515 4.206098 n.a. n.a. 0.985736282780 -0.4398583 0.00098859510795 0.0523049 62.3758 /T 117.5733 68.8/ 0.5623 n.a. n.a. 56.890094 96.081156 4.3940534 2024-Nov-30 13:30 N 18 10 01.78 +35 45 14.1 48.140003 5.544119 n.a. n.a. 0.985734528179 -0.4350919 0.00098877555348 0.0377444 62.4295 /T 117.5196 68.8/ 0.5552 n.a. n.a. 55.650869 96.009600 3.2423328 2024-Nov-30 13:40 N 18 10 46.72 +35 44 15.0 49.439632 6.913254 n.a. n.a. 0.985732792676 -0.4303352 0.00098889845231 0.0236109 62.4826 /T 117.4664 68.9/ 0.5483 n.a. n.a. 54.400196 95.961927 2.0739444 2024-Nov-30 13:50 N 18 11 30.62 +35 43 17.7 50.716080 8.312360 n.a. n.a. 0.985731076231 -0.4255879 0.00098896553636 0.0099140 62.5349 /T 117.4141 68.9/ 0.5416 n.a. n.a. 53.139409 95.940176 0.8886235 2024-Nov-30 14:00 N 18 12 13.49 +35 42 21.7 51.970068 9.740330 n.a. n.a. 0.985729378809 -0.4208495 0.00098897857459 -0.0033375 62.5864 /T 117.3626 69.0/ 0.5352 n.a. n.a. 51.869923 95.946588 -0.313858 2024-Nov-30 14:10 Cm 18 12 55.30 +35 41 27.0 53.202361 11.196088 n.a. n.a. 0.985727700374 -0.4161197 0.00098893937052 -0.0161352 62.6369 /T 117.3121 69.1/ 0.5289 n.a. n.a. 50.593240 95.983626 -1.533677 2024-Nov-30 14:20 Cm 18 13 36.06 +35 40 33.1 54.413757 12.678593 n.a. n.a. 0.985726040891 -0.4113982 0.00098884975968 -0.0284716 62.6863 /T 117.2627 69.1/ 0.5230 n.a. n.a. 49.310949 96.053998 -2.770949 >..... 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/hrzn_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************