1996-008A
The first Discovery probe was NEAR, the Near Earth Asteroid Rendezvous. It was built and operated by JHU-APL. The box-shaped satellite had 4 fixed (but hinged) solar panels and no extensible booms to save money; the science instruments were in the base of the bus. An Aerojet propulsion system included a 100lb LEROS 1 thruster. Launch mass was 805 kg full, 468 kg dry, 337 kg prop. (816 full 475 kg dry per APLTD19-2-157, APLTD23-1-73). The propulsion system mass was 438 kg. The vehicle is a box 2.80m tall and 1.47m in diameter with four deployable solar panels attached to the upper edge and a 1.5m high gain antenna. The despin cables are around 12m long.
NEAR was launched by a Delta into a hyperbolic trajectory with C3 = 26 (km/s)2.
NEAR flew past (253) Mathilde in 1997. Mathilde was the first C-type asteroid to be visited and was found to have a diameter of 52 km. Flyby speed was 10 km/s.
In Dec 1998, the biggest burn to date was planned: a 650 m/s burn of the main engine. A 3-minute fuel settling burn was successful, but then 0.2s after ignition for the main burn the engine aborted with only 0.2m/s of velocity change. The failure resulted in a 1 km/s flyby of Eros. A burn on 1999 Jan 3 placed NEAR in a rendezvous orbit with a maximum distance of 1 million km, with re-rendezvous on 2000 Feb at 0.04 km/s. Orbit insertion was successful on Valentine's Day 2000. Eros has a mass of around 7 teratonnes and a 50 km radius orbit around it has a period of about 30 hours. In Mar 2000 NEAR was renamed NEAR Shoemaker in honor of planetary scientist Eugene Shoemaker.
On Feb 12, NEAR landed on Eros at 35S 279W. Impact was 1.9m/s; signals were received after touchdown confirming NEAR survived the impact. NEAR was switched off on Feb 28.
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| NEAR |
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| Date | Time | Event | Orbit |
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| 1996 Feb 17 | 2043:27 | Launch by Delta 7925-8 | CC LC17B |
| | 2044 | 6 SRB sep |
| | 2045 | 3 SRB sep |
| | 2047:55 | MECO |
| | 2048:07 | Stage 1 sep |
| | 2048:12 | Stage 2 ignition |
| | 2048:24 | Faring sep |
| | 2052:50 | Stage 2 SECO1 | 180 x 185 x 28 |
| | 2105:20 | Stage 2 burn 2 |
| | 2108 | Stage 2 SECO2 | 172 x 5550 |
| | | Spinup Stage 3 to 59 prm |
| | 2108:29 | T+25:02 St 2 sep |
| | 2109 | Stage 3 burn 87s |
| | 2110 | Stage 3 cutoff |
| | 2112? | Stage 3 sep, 1.8m/s |
| | | Yo-yo despin of NEAR to 0.8 rpm |
| | 2117 | NEAR detumble burn |
| | | Delta stage 2 depletion burn |
| 1996 Feb 18 | 0357 | Pass EL1:4 |
| 1996 Feb 21 | 0350? | Leave Earth sphere |
| 1996 Feb 24 | 2132 | | Desat burn |
| 1996 Mar 2 | 2000 | TCM-1; reduced Mathilde flyby from 869000 km to 82000 km |
| 1996 Mar 23 | 1200 | | 0.98 x 2.18 AU x 0.76 deg |
| 1996 May 13 | | Geotail crossing |
| 1996 Sep 13 | 1700 | TCM-2A |
| 1996 Sep 13 | 1730 | TCM-2B, trim Mathilde miss to 2440 km |
| 1997 Jan 6 | 1300 | TCM-3 |
| 1997 Jan 29 | 1400 | TCM-4, trim miss to 1032 km |
| 1997 Jun 18 | | TCM-5 |
| 1997 Jun 27 | 1245 | Enter Mathilde sphere |
| 1256:01 | Flyby (253) Mathilde at 1256 km, 2.0AU |
| 1310 | Leave Mathilde sphere |
| 1997 Jul 3 | 0630:00 | TCM-7 (DSM-1) Deep space maneuver for Earth flyby, 269 m/s |
| 1997 Jul 23 | | TCM-8 (DSM-2), 5 m/s |
| 1997 Sep 24 | | NLR and NIS covers opened (not ejected) |
| 1997 Nov 17 | 1600 | TCM-9 targeting 1m/s |
| 1998 Jan 9 | 1500 | TCM-10 0.1 m/s |
| 1998 Jan | | | 0.52 x 0.95 AU x 2.18 |
| 1998 Jan 20 | 2011 | Enter Earth L1 sphere |
| 1998 Jan 23 | 0723 | Earth flyby 532 km over Iran |
| 1998 Jan 25 | 1841 | Depart Earth L1 sphere |
| 1998 Feb | | | 0.98 x 1.77 AU x 10.04 |
| 1998 Feb 11 | 1400 | CAL-1 thruster cal test 0.01 m/s |
| | 1430 | CAL-2 test |
| | 1500 | CAL-3 test |
| | 1700 | CAL-4 test |
| | 1730 | CAL-5 test |
| 1998 Apr 1 | 1600 | TCM-12, post-swingby targeting 1m/s |
| 1998 Oct 14 | 1700 | TCM-15 0.3 m/s |
| 1998 Dec 20 | 2200 | TCM-16 Eros braking 1, aborted |
| 1998 Dec 23 | 1842:15 | Flyby Eros at 3827 km, 0.965 km/s |
| 1999 Jan 3 | 1700 | TCM17/DSM-2 0.94km/s, 24 min 940m/s |
| 1999 Jan 20 | 1700 | TCM-18 DSM-2 cleanup burn 14m/s |
| 1999 Aug 12 | 1700 | TCM-19 2-min burn 21m/s |
| 1999 Oct 20 | 1530 | TCM-20, |
| 1999 Dec 6 | 1530 | TCM-21 |
| 2000 Feb 2 | 0500 | Safemode |
| | | Control recovered |
| 2000 Feb 3 | 1700 | TCM 22, range = 8000 km |
| 2000 Feb 8 | 2200 | TCM 23s, range = 4600 km |
| 2000 Feb 11 | 1533 | Enter Eros hill sphere |
| 2000 Feb 14 | 0758:48 | Flyby at 182 km from center |
| 1533:06 | Eros orbit insertion 57s, 333 km from Eros center |
| | 1534:03 | Cutoff | 321 x 366 km T=27.6d |
| 2000 Feb 24 | 1700 | Descent burn OCM-1 | 204 x 366 km |
| 2000 Mar 3 | 1800 | OCM-2 22s | 205 x 205 km |
| 2000 Mar 10 | | | 205 x 205 |
| 2000 Apr 2 | 0203 | OCM-3 | 101 x 209 |
| 2000 Apr 11 | 2120 | OCM-4 | 100 x 100 |
| 2000 Apr 22 | 1750 | OCM-5 | 50 x 101 |
| 2000 Apr 30 | 1615 | OCM-6 2:20 dv=5 kph v=11kph | 49 x 52 x 89.6 |
| 2000 May 13 | | NIS shut down |
| 2000 Jul 7 | 1800 | OCM-7 | 35 x 50 x 90 |
| 2000 Jul 14 | 0300 | OCM-8 | 34 x 39 x 90 |
| 2000 Jul 24 | 1700 | OCM-9 | 37 x 50 x 90 |
| 2000 Jul 31 | 2000 | OCM-10 | 49 x 51 x 90 |
| 2000 Aug 8 | 2325 | OCM-11 inc change | 50 x 52 x 105 |
| 2000 Aug 26 | 2325 | OCM-12 2min burn | 49 x 102 x 113 |
| 2000 Sep 5 | 2300 | OCM-13 | 100 x 103 x 115 |
| 2000 Oct 13 | 0545 | OCM-14 | 50 x 98 x 130 |
| 2000 Oct 20 | 2140 | OCM-15 | 50 x 52 x 133 |
| 2000 Oct 25 | 2210 | OCM-16 | 51 x 19 x 131 |
| 2000 Oct 26 | 0655:10 | 5.5km close flyby |
| 1740 | OCM-17 | 64 x 203 x 145 |
| 2000 Nov 3 | 0300 | OCM-18 3.5s | 194 x 196 x 147 |
| 2000 Dec 7 | 1520 | OCM-19 | 34 x 193 x 179 |
| 2000 Dec 13 | 2015 | OCM-20: begin XGRS science | 33 x 37 x 179 |
| 2001 Jan 24 | 1605 | OCM-21 | 21 x 35 x 179 |
| | | 6 km flyby |
| 2001 Jan 26 | | within 4.9 km |
| 2001 Jan 27 | | within 13 km |
| 2001 Jan 28 | 0125 | OCM-22 | 19 x 37 x 179 |
| 1024 | 2.7km flyby |
| | 1805 | 3.8s burn, OCM-23 |
| 2001 Jan 28 | 1345 | OCM-23 | 35 x 36 x 178 |
| 2001 Feb 2 | 0900 | OCM-24 | 35 x 37 x 178 |
| 2001 Feb 6 | 2315 | OCM-25 | 33 x 35 x 178 |
| 2001 Feb 12 | 1513:36 | EMM-1 Deorbit 20s | 7.5 x 35 x 135 |
| | 1858:35 | EMM-2 braking 3min | 5 alt x 35 x 50 |
| | 1914 | EMM-3 5min12s | 3 alt x 35 x 50 |
| | 1930 | EMM-4 6min | 1km alt x 35 x 50 |
| | 1942 | EMM-5 4min | 350 alt |
| | Last image from 120m |
| 1944:17 | Landed on Eros, 1.9m/s |
| | | 279.3W 40.0S |
| 2001 Feb 13 | 0130? | One telemetry frame received |
| 2001 Feb 14? | | XGRS and magnetometer movements |
| 2001 Mar 1 | 0000 | end of mission |
| |
Payload:
- MSI Multispectral imager 4400A-1.1mu 2 deg FOV
- MAG Magnetometer
- NIS Near IR spectrometer 0.8-2.6 microns
- XRS X-ray spectrometer 1-10 keV;
- GRS gamma ray spectrometer 0.3-10 MeV