Star Quality

 https://welib.org/md5/8f2c237afa9d909add1a6e7a542d512c

Phobos 1

 1988-058A

---

The Fobos missions were the first of the fourth generation planetary probes, using a bus derived from both the 4V planetary probe and the E-8 lunar probe. Work began on the project in 1976. The first Fobos spacecraft, 1F No. 101, was launched on 1988 Jul 7 aboard a Proton-K. The three-stage Proton placed Fobos and the specially modified 11S824F (Blok-D-1) fourth stage on a suborbital trajectory. The Blok-D-1 ignited to enter parking orbit, and then coasted until a second burn. The second burn left Fobos-1 in a highly eccentric orbit, and solar orbit insertion was completed using the Fobos spacecraft's own ADU propulsion unit.

On 28 Aug 1988 an error was made in a command to switch on the gamma ray spectrometer; the command actually sent instructed Fobos 1 to turn off its orientation and stabilization system. With the solar panels away from the Sun, the batteries ran down. On the next comms pass on Sep 2, nothing was heard from the probe, although loss of contact was not officially admitted until 1988 Nov 3.

Fobos-1
Date	Time	Event	Orbit
1988 Jul 7	1738:04	Launch by Proton-K	KB
	1747	Stage 3 MECO
	1747	Stage 3 sep
1988 Jul 7	1753:50	Blok-D-2 burn (T+15:46) 95s
	1755:25	Blok-D-2 cutoff (T+17:21)	88.13 169 x 197 x 51.5
	1810	Equator crossing southbound
	1841	Perigee of post-sep D-2 orbit
	1847?	SOZ units sep
	1847?	Blok-D-2 burn 530s?
	1854	SOZ eq crossing north
	1856?	MECO-2
	1900?	Blok-D-2 sep
		Blok D-2 venting	2628 x 130504 x 50.8
	1905?	ADU burn, solar orbit insertion
		Control to OKIK-16/Yevpatoria
1988 Jul 16		TCM-1 8.9m/s
1988 Aug 18		Control to TsNIIMash/Kaliningrad
1988 Aug 28		Command error
1988 Sep 1		failed to respond to commands
1989 Jan 23		Mars flyby

Payload:

• Terek Solar X-ray spectrometer

• SUFR Solar UV

• IPNM Neutron radiation study

• GRUNT Penetrating radar

• ADU Propulsion unit

• DPS Lander

Phobos 2

 1988-059A

---

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)