Monday, December 3, 2001

Lunar Prospector

 1998-001A


Lunar Prospector was selected in Mar 1995 as part of the Discovery program. It will be built and operated by Lockheed Missiles and Space Co/Sunnyvale; NASA oversight of the project is managed by NASA-Ames which also controls the probe.

The spacecraft is a spin stabilized solar-panel-covered cylinder 1.4m dia, 1.22m high surrounding a triangular inner structure based on the Iridium satellite, and has a hydrazine propulsion system with six Olin MR-106E 22N thrusters with total mission impulse of at least 239 kNs. Three booms unfold to carry the experiments, a magnetometer boom 3.8m long and two instrument booms 2.5m long. Mass is 158 kg dry, 296 kg fuelled. The spacecraft carried a special Celestis capsule with some of the ashes of lunar scientist Gene Shoemaker, who died in a car accident the previous year.

Launch was Jan 1998 by LMA Athena-2 with a Model 92 fairing (92 inch diameter) from Cape Canaveral's Florida Spaceport Authority LC46. It will be inserted in a 100 x 100 km, 118 min lunar polar orbit. The Athena-2 has two Castor 120 stages, an Orbus 21D Equipment Section Boost Motor, and an Orbit Adjust Module.

As well as the LP payload, Athena-2 carries a TLI stage. The TLI stage is built around a Thiokol Star 37FM (TE-M-783-7) solid motor and a Thiokol graphite interstage adapter. The TLI Stage is 0.17m long and 0.21m in diameter with a fueled mass of 1227 kg and an empty mass of 212 kg. (The Star 37FM has thrust 45.8 kN, impulse 2894 kNs and burn time 63s, with diameter 0.94m and length 1.68m). The TLI stage also has spinup motors which fire prior to LP separation to spin-stabilize the LP.

Launch mass of S/C + TLI stage is 1523 kg.

The neutron spectrometer will help in the search for hydrogen and water ice; the alpha particle spectrometer will detect outgassing events. 

In 1998 preliminary evidence was reported for substantial amounts of ice at the lunar poles.

End of mission in 1999 will have impact at 42E 87.7S.

According to Alan Binder's book on LP the TLI stage reentered over the Indian Ocean 'several days after launch'. First perigee may have been around 2030 UTC Jan 15.


LP 
 

DateTimeEventOrbit  

1998 Jan 7  0228:44  Launch by LMLV-2  SPFL LC46  
  T+01:29 Stage 1 (Castor 120) sep, 18 km 
  T+01:29 Stage 2 burn 
  T+03:00 Stage 2 (Castor 120) sep, 95 km 
  T+03:52 Fairing sep, 132 km 
  T+03:57 Stage 3 (Orbus 21D) burn, 134 km 
 0235:15  T+06:31 Stage 3 sep, 156 km 
 0235:15  T+06:31 OAM burn 418s 
 0242:13  T+13:29 OAM cutoff, injection 156 km 
  Parking orbit  153 x 202 x 29.2 
  OAM orient for TLI 
 0323:57 T+55:13, U+0:00 OAM sep  141 x 198 x 29.3  
 0323:58  U+0:01 TLI stage spinup 
 0324:17  U+0:20 TLI burn 
 0325:20  U+1:23 TLI burnout - MET 0 
 0325:26  U+1:29 TLI stage sep 
 0524  TLI sep confirmed 
   197 x 352645 x 29.20 
1998 Jan 7  0630  Mag boom deploy 
 0709  Booms deploy 
 0730  Booms extended 
 0920? OAM reentered? 
   76 x 381571 x 29.3 
 1155  MCM-1 burn 13.0m/s axial, 49m/s tgtl. 
 1840  Pass EL1:4 
 1851  TLI stage pass EL1:4? 
1998 Jan 8  0825 MCC-2, 8.4m/s 
   -267 x 379973 x 29.3 
1998 Jan 10  1812  Enter L sphere  73 x -17841 x 89.7 
1998 Jan 11  0156 Equigravisphere 
1998 Jan 11  1145  LOI burn, 32 min 
1998 Jan 11  1217  LOI, 12 hr orbit  84 x 8470 x 89.72  
 1740  Capture correction  
1998 Jan 12  1058 LOI-2, 27 min to 3.5 hr period  87 x 1861 x 89.9 
 1125 End of burn 
1998 Jan 13  1206  LOI-3, 118 min op orbit  120.01 92 x 153 x 90.0 
1998 Jan 15  2144  76s trim  92 x 100 x 90.1 
 2206  16s trim  99 x 100 x 90.1 
 2357  Move to mapping attitude 
1998 Jan 16    117.88 99 x 101 x 90.6 
1998 Jan 22  0000   118.0 80 x 120 x 90.1 
1998 Jan 24  0000   118.0 90 x 110 x 90.1 
1998 Jan 27  0000   118.0 88 x 112 x 90.1 
1998 Jan 30  0000   118.0 86 x 114 x 90.1 
1998 Feb 2  1800   118.0 96 x 104 x 90.1 
1998 Feb 10  0000   118.0 92 x 109 x 90.1 
1998 Feb 19  0000   118.0 85 x 115 x 90.3 
1998 Mar 6  0000   118.0 82 x 117 x 90.0 
1998 Mar 8  0349  OTM-1a periselene raise 
1998 Mar 8  0453  OTM-1b aposelene lower 
1998 Mar 12  0000   118.0 94 x 106 x 90.7 
1998 Mar 19  0000   118.0 84 x 115 x 90.4 
1998 Apr 2 0000   118.0 93 x 105 x 90.2 
1998 Apr 16  0000   118.0 87 x 110 x 90.0 
1998 Apr 23  0000   118.0 82 x 118 x 90? 
1998 May 1    118.0 85 x 114 x 90? 
1998 May 1  1550  Circ burn 38s  118.0 112 x 114 x 90 
1998 May 1  1654  Circ burn, exchange peri 37s  88 x 112 x 90 
1998 May 5  0000   118.0 88 x 112 x 90.9 
1998 May 15  0000   118.0 86 x 114 x 90? 
1998 Jun 25    83 x 118 x 90 
1998 Jun 25  2142  MOC periapsis raise  109 x 118 x 90 
 2246  MOC apo lower  90 x 109 x 90 
1998 Jun 26  0000   118.0 90 x 110 x 89.8 
1998 Jul 10  0000   118.0 90.2 x 108.6 x 89.9 
1998 Nov 13  1800   118.0 93 x 106 x 90.0 
1998 Dec 4  1800   118.0 91 x 109 x 90 
1998 Dec 19  1740   77 x 122 x 90 
1998 Dec 19  1811  Lower orbit, 47s  50 x 77 x 90 
1998 Dec 19  1911  Lower orbit, 150s 112.0 25 x 55 x 90 
1998 Dec 30  0000   112.0 29 x 52 x 90 
1999 Jan 8  0000   112.0 31 x 49 x 90 
1999 Jan 15  1800   112.0 30 x 50 x 90 
1999 Jan 29  0655  40s burn  43 x 63 x 90 
 0743  71s burn  15 x 45 x 90 
 2359   17 x 43 x 90 
1999 Feb 3  0000   111.0 21 x 39 x 90 
1999 Feb 11  0000   111.0 26 x 33 x 90 
1999 Feb 19  0000   111.0 20 x 40 x 90 
1999 Feb 25    16 x 40 x 90 
1999 Feb 25  1116  Orbit raise  40 x 44 x 90 
 1155  Orbit lower  15 x 44 x 90 
1999 Mar 5  0000   111.0 27 x 32 x 90 
1999 Mar 12  0000   111.0 23 x 36 x 90 
1999 Mar 19  0000   111.0 15 x 45 x 90 
1999 Mar 25  1730  Orbit burn EMOC-3 43s 
 1810  Orbit burn EMOC-3 47s  111.0 15 x 45 x 90 
1999 Apr 2  0000   111.0 27 x 32 x 90 
1999 Apr 9  0000   111.0 22 x 37 x 90 
1999 Apr 16  0000   111.0 12 x 47 x 90 
1999 Apr 20  0132  Orbit burn EMOC-4 45s, 7m/s 
 0214  Orbit burn EMOC-4 45s, 7m/s 
1999 Apr 23  0000   111.0 21 x 38 x 90 
1999 Apr 30  0000   111.0 23 x 36 x 90 
1999 May 5  1735  Orbit burn EMOC-5 25s, 4m/s 
 1833  Orbit burn EMOC-5 26s, 4m/s 
1999 May 7  0000   111.0 21 x 38 x 90 
1999 May 14? 0000   111.0 19 x 41 x 90 
1999 May 21  0000   111.0 17 x 43 x 90 
1999 May 28  0000   111.0 17 x 42 x 90 
1999 Jun 1  2340  Orbit burn EMOC-6 45s 7m.s 
1999 Jun 2  0051  Orbit burn EMOC-6 45s 7m/s 
1999 Jun 4  0000   111.0 17 x 42 x 90 
1999 Jun 11  0000   111.0 17 x 42 x 90 
1999 Jun 18  0000   111.0 14 x 46 x 90 
1999 Jun 25  0000  111.0 18 x 42 x 90 
1999 Jun 29  1511  Orbit burn EMOC-7 47s 7m/s 
1999 Jun 29  1622  Orbit burn EMOC-7 46s 7m/s 
1999 Jul 1  0000  111.0 17 x 42 x 90 
1999 Jul 9  0000  111.0 18 x 42 x 90 
1999 Jul 16  0000 111.0 19 x 41 x 90.0 
1999 Jul 23  0000  111.0 20 x 39 x 90.0 
1999 Jul 26  1401 Orbit burn 9s, 1.4m/s  
1999 Jul 28   Lunar eclipse  111.0 11 x 49 x 90.0 
1999 Jul 30  0815Apogee raise 40m/s, 256s   
 2200 120.0 17 x 234 x 90.0 
1999 Jul 31  0900  LOS, to farside 
1999 Jul 31  0915:55  Lower periapsis negative, -44m/s, 4:36  -163 x 234 x 90 
1999 Jul 31  0952:00  Impact in Mawson 87.7S 42.1E 
  1.7 km/s at 6 deg, mass 158 kg 

Payload:

  • Neutron spectrometer (on mast) (LANL)

  • Gamma ray spectrometer (LANL)

  • Alpha particle spectrometer (on mast ) (LANL/LM)

  • Magnetometer and electron spectrometer (MAG/ER) (UCB)

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