NEAR Shoemaker

 1996-008A

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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.

 

NEAR
Date	Time	Event	Orbit
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