{"signature":{"source":"NASA/JPL Horizons API","version":"1.2"},"result":"*******************************************************************************\n Revised:  Feb 08, 2023             STEREO-B Spacecraft                    -235\n                                http://stereo.gsfc.nasa.gov/\n NOTE: \n  Contact with STEREO-B was lost 2014-Oct-01. \n\n  After 22 months, contact was regained at 22:27 UTC on August 21, 2016, when \n  the Deep Space Network established a lock on STEREO-B for 2.4 hours. The\n  trajectory here is updated to use that tracking data. \n\n  It has been determined the spacecraft is in an uncontrolled spin of \n  3 deg/second. \n\n  2023-Feb-08:\n   There has been no contact or new tracking data since 2016, but an updated\n   prediction was added to support a search effort.\n\n  2017-Sep-20: \n   Fix did NOT occur. Last contact with the spacecraft was September 23, 2016.\n\n  2016-Oct-14: \n   Another opportunity to potentially fix the spacecraft will not occur until \n   mid-2017. Once its computer is powered on there will be about two minutes \n   to upload the fix before STEREO-B enters failure mode again. \n\n  http://stereo-ssc.nascom.nasa.gov/behind_status.shtml\n\n BACKGROUND:\n  STEREO (Solar TErrestrial RElations Observatory) is the third mission in \n  NASA's Solar Terrestrial Probes program (STP). This two-year mission will use\n  two nearly identical space-based observatories - one ahead of Earth in its \n  orbit, the other trailing behind - to provide stereoscopic measurements to \n  study the Sun and the nature of coronal mass ejections (CMEs).\n\n OBJECTIVES:\n  * Understand the causes and mechanisms of coronal mass ejection (CME) \n     initiation.\n  * Characterize the propagation of CMEs through the heliosphere.\n  * Discover the mechanisms and sites of energetic particle acceleration in \n     the low corona and the interplanetary medium.\n  * Improve the determination of the structure of the ambient solar wind. \n\n SPACECRAFT:\n  Launch (Delta II 7925-10L) = October 26, 2006 @ 1:53\n  Mission end                = 2 year nominal mission after launch\n  Dimensions                 = 1.14m x 1.22m (launch), 6.47m x 2.03m (deployed)\n  Launch Mass                = 620 kg  (includes propellant)\n  Power consumption          = 475 watts\n  Data downlink              = 720 kilobits/sec\n  Memory                     = 1 GB\n  Attitude                   = control within 7\", knowledge within 0.1\"\n\n INSTRUMENTS (4 packages on each spacecraft):\n  * Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)\n  * STEREO/WAVES (SWAVES) radio burst tracker\n  * In-situ Measurements of Particles and CME Transients (IMPACT)\n  * PLAsma and SupraThermal Ion Composition (PLASTIC) \n\n ORBIT:\n  STEREO-A and STEREO-B will be launched together, then separate. The Moon's \n  gravity will be used to redirect the observatories to their appropriate \n  orbits, something the launch vehicle alone is not able to do.\n\n  For the first three months after launch, the two observatories will fly in \n  highly elliptical orbits extending from very close to Earth to just beyond \n  the Moon's orbit. STEREO Mission Operations personnel at APL will \n  synchronize spacecraft orbits so that about two months after launch they \n  encounter the Moon, at which time one of them is close enough to use the \n  Moon's gravity to redirect it to a position \"ahead\"/leading the Earth.\n  Approximately one month later, the second observatory will encounter the \n  Moon again and be redirected to its orbit \"behind\"/trailing the Earth.\n\n POST-LAUNCH SPACECRAFT TRAJECTORY\n   Merged segments, includes 2016-Aug-21 recovery tracking data update, \n   with long-term predictions after 2016-Sep-12:\n\n  Trajectory name                             Start        Stop\n  -------------------------------------    -----------  -----------\n  concatenated DEPM trajectory segments    2006-Oct-26  2014-Sep-28\n  235_120day_20140928_01.V0.2              2014-Sep-28  2014-Nov-25\n  235_120day_20141125_01.V0.2              2014-Nov-25  2015-Jan-01\n  235_1461day_20150101_01.V0.2             2015-Jan-01  2015-Jul-16\n  235_1460day_20150716_01.V0.2             2015-Jul-16  2016-Jan-29\n  235_5295day_20160129_01.V0.5             2016-Jan-29  2016-Aug-21\n  behind_2016_256_01.depm                  2016-Aug-21  2016-Sep-12\n  235_5295day_20160129_01.V0.5             2016-Sep-12  2020-Oct-27\n  235_baseline_1460day_20201027_01         2020-Oct-27  2024-Oct-26\n******************************************************************************\n"}