API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised : May 05, 2020 NEAR Spacecraft / (Sun) -93 Web-site: Feb 10, 2013 http://near.jhuapl.edu/sci-eng.html BACKGROUND The NEAR-Shoemaker spacecraft studied the near-Earth asteroid 433 Eros from orbit over one year. 230 orbits were completed before the spacecraft was set down in the north pole saddle region. Mission objectives at Eros were to assess bulk properties: shape, composition, mineralogy, internal mass distribution (gravity field), and magnetic field. Other studies included regolith properties, interactions with solar wind, spin state, and any ongoing processes indicated by dust or gas. While en-route to Eros, the spacecraft flew past the asteroid 253 Mathilde at a distance of 1211 km, imaging 60% of its surface and determining the mass parameter (GM). The first attempt at Eros orbit insertion failed, requiring the spacecraft orbit the Sun for another year before making a second, successful attempt. Upon completion of this first in NASA's Discovery-class series, NEAR-Shoemaker became the first spacecraft to land on an asteroid, where it was left. DATES Launched : 1996-Feb-17 20:43:17 UTC Delta II 7925-8, Cape Canaveral Mathilde flyby : 1997-Jun-27 12:55:55 UTC @ 1210.7 km from center Earth flyby : 1998-Jan-23 07:22:57 UTC @ 6910.7 km from center, 533 km alt (over 47.1856 E, 33.0926 N; Iran, ~280 km east of Baghdad) Eros orbit insertion First attempt : 1998-Dec-20 22:00 UTC (aborted) Rendevous burn: 2000-Feb-03 17:00 UTC Eros insertion: 2000-Feb-14 15:33 UTC Touchdown : 2001-Feb-12 19:44:16 UTC (bounced) Landing : 2001-Feb-12 20:01:52 UTC Last radio comm: 2001-Feb-28~00:00 UTC SPACECRAFT Size : octagonal, 1.7 m per side Launch mass : 800 kg Dry mass : 487 kg Power : 400 watts @ 2.2 au (max. distance from Sun) 1800 watts @ 1 au Communications : 1.5 m X-band antenna Propulsion : 450 Newton main thruster Four 21 N & seven 3.5 N hyradizne thrusters 1450 m/s total delta-V (209 kg hydrazine 109 kg NTO oxidizer) TRAJECTORY Concatenation of JPL navigation solutions. Includes all modeling of the time; solar pressure, maneuver reconstruction, and Eros gravity w/spin-state soln. Merged solutions from JPL navigation: File Start Stop ----------------------------------- ----------------- ----------------- p_tcm2_n0a 1996-Feb-19 02:00 1996-Apr-02 00:00 p_tcm2_n1d 1996-Apr-02 00:00 1996-May-31 00:00 near_cruise_nav_v1 1996-May-31 00:00 2000-Jan-01 01:00 near_erosorbit_nav_v1 2000-Jan-01 00:00 2001-Feb-12 19:45 Usage notes: To produce output relative to 433 Eros or 253 Mathilde flight-project target trajectories, specify coordinate center "@2000433" or "@2000253". The mission-consistent DE403 target-body trajectory solutions used are "eros80" (which includes 75 30-m 1-sigma delay measurements of Eros synthesized from spacecraft tracking) and "math9749". *******************************************************************************