Phobos 2

 1988-059A

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The second Fobos, 1F No. 102, was launched on 1988 Jul 12 using the same profile as 1F No. 101.

The spacecraft would have deployed landers on the surface of Phobos. As well as the long-lived lander, Fobos-2 carried a 'hopper' lander.

On Mar 21 Fobos-2 entered a quasisynchronous orbit relative to Phobos, ranging between 200 and 600 km from the moon.

The spacecraft failed for unknown reasons on 1989 Mar 27. The failure review determined that most likely the problem was with the on-board computer, although meteorite hits or an electrical charging problem were not ruled out. The probe lost orientation and then electrical power. The plan had been for Phobos rendezvous and lander separation on 1989 Apr 4-5.

Fobos-2
Date	Time	Event	Orbit
1988 Jul 12	1701:43	Launch by Proton-K	KB
	1711?	Stage 3 MECO
	1711?	Stage 3 sep
1988 Jul 12	1717:30?	Blok-D-2 burn 1
	1719:04?	Blok-D-2 cutoff	88.07 161 x 197 x 51.51
	1810?	SOZ units sep
	1810?	Blok-D-2 burn 2
	1818?	Blok D-2 MECO-2	170? x 130000? x 50.8?
	1820?	Blok-D-2 sep
	1820?	ADU burn, solar orbit insertion
1988 Jul 21		TCM 1 9.3m/s
1988 Nov 1		one transmitter out of order
1989 Jan 23		TCM 2 (Earth range 177Mkm) 20.8m/s
1989 Jan 24	2030?	Enter Mars sphere
1989 Jan 29	1255	Mars orbit insertion 815.1m/s	79h 37m 867 x 81357 x 0.9
1989 Feb 12	1300	OTM 114.6m/s	86.5h 6408 x 81346 x 0.9
1989 Feb 18	1406	ADU burn 722m/s	8h 6145 x 6409 x 1.26
1989 Feb 18		ADU sep
1989 Feb 21		First Phobos imaging, 860 km
1989 Feb 28		Pass 320 km from Phobos
1989 Mar 7	1226	TCM 37.6m/s with OA's DU
1989 Mar 15	1420	TCM 1.0m/s
1989 Mar 21	1446	TCM 39.7m/s	200 km from Phobos, sync
1989 Mar 25		191 km from Phobos
1989 Mar 26?		TCM?
1989 Mar 27	1159	Final Phobos imaging
1989 Mar 27	1650	Faint signal received, s/c tumbling
1989 Mar 27		end of ops

Payload:

• ADU = Avtonomnaya Dvigatel'naya Ustanovka

• OPB (Orbiter/Lander Unit)

• APEX gamma ray bursts

• LET 0.9-75 MeV cosmic rays

• SLED 20-140 keV e, 20 -3400 keV p, 0.1-3.4 MeV alpha

• Fregat TV system

• Radiometer

• Photometer

• IR spectrometer

• FGMM-1 magnetometer

• Lima-D laser

• Mass spectrometer

• Dion Kr ion gun, Fobos 2 only

• DPS Lander probe (LAS)

  • Radio beacon

  • Seismometer

  • XR flourescence spectrometer

  • Razrez penetrometer

  • Panoramic TV system

• Hopper probe (PPS)