Voyager 2

 1977-076A

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Voyager SC3 (Voyager 2, VGR-2) was launched at 1429:44 on 1977 Aug 20 by Titan IIIE Centaur from LC41 at Cape Canaveral. Although it immediately encountered problems with its science boom and other systems, these were soon resolved and it would become probably the most successful probe ever, visiting four planets and revolutionizing our knowledge of the outer solar system.

The Centaur stage cutoff into an orbit with an aphelion of around 2.8AU. The VGR propulsion module - a Star 37 motor - fired to increase aphelion to 6.3AU.

The scan platform stuck during deployment; an attempt to shake it by jettisoning a dust cover failed when the command sent VGR-2 into safemode.

VGR-2 settled into Cruise mode on Sep 2, and made a TCM on Oct 11. However, the success of launch led to complacency and the Voyager program ran into management problems at this time, with operations errors nearly losing the vehicle. Many Voyager team members moved on to work on the future Galileo project, with Voyager project manager John Casani's attention had been split between Voyager and Galileo Bob Parks was brought in to take over Voyager full-time in April 1978, soon after a crisis in which the main radio receiver switched to the backup when no message was sent to the spacecraft for over a week. A capacitor in the backup shorted, but when controllers ordered a switch back to the main reciever it failed permanently, and a week later the backup cut back in, to be used thereafter.

The first Jupiter imaging was done on 1979 Apr 24, with Jupiter Observatory Phase starting in May 1979. TCMs on May 26 and Jun 27 were made before encounter on Jul 9. TCM5, 6 and 7 were made on Jul 9, Jul 23 and 1981 Feb 26.

The Saturn Observatory Phase began on 1981 Jun 5. TCM-8 on Jul 19 and TCM-9 on Aug 18 set up the final encounter geometry. Far Encounter phases 1 and 2 began on Jul 31 and Aug 11 respectively, with Near Encounter on Aug 25. Periapsis was at 0324 on Aug 26. Voyager 2 crossed the ring plane at the G ring at 0415. The scan platform failed at 0514 on Aug 26, but most of the imaging had been taken. A Saturn Post Encounter phase lasted from Aug 27 to Sep 28.

Voyager 2 was now on course for Uranus. TCM-10 (1981 Sep 29), TCM-11 (1984 Nov 13), and another TCM on 1985 Dec 24 set up the encounter, which happened on 1986 Jan 26. The results were eclipsed by the loss of the Space Shuttle Challenger two days later.

During the Neptune cruise phase, TCM B15 (1987 Mar 13), TCM B16 (late 1988), TCMB17C (1989 Apr 20), TCM B18 (about 1989 Aug 1) and TCM B20 (1989 Aug 21) set up the accurate flyby. The Neptune Observatory Phase began on Jun 5, and transitioned to Far Encounter on Aug 6 and Near Encounter on Aug 24. Voyager 2 encountered Neptune at a distance of 4h 6min from Earth. At 2356 on Aug 24, it passed 4.6 million km from Nereid; at 0253 on Aug 25 it crossed the Neptune ring plane inbound. Closest approach to Neptune was 4905 km at 0355. The ring plane was traversed outbound at 0514, and Voyager 2 made its final flyby, of Triton, at a distance of 38360 km on 1989 Aug 25 at 0919. A Neptune Post Encounter phase from Aug 20 to Oct 2 marked the end of the Voyager outer planets exploratory mission. Voyager now began the search for the heliopause - the boundary between the solar system and interstellar space. Beginning of the Voyager Interstellar Mission was declared on 1990 Jan 1. By 1992 Oct 9, Voyager 2 was 38 AU from the Sun.

In 1999, five experiments were still operating: the CR, LEPI, PSI, PWI, and MAG.

Voyager 2
Date	Time	Event	Orbit
1977 Aug 20	1429:44	Launch by TC	CC LC41
		T+1:50 SRM cutoff
		T+1:51 St 1 burn
		T+2:02 SRM sep
		T+4:15 St 1 MECO
		T+4:15 St 1 sep, St 2 MES
		T+4:26 CSS jettison
		T+7:44 St 2 MECO
		T+7:50 St 2 sep
		T+8:01 TC MES-1
	1439:25	T+9:48 TC MECO-1	167 x 167 x 37.6
		T+53:00? Science boom deploy failed
	1523:20	T+53:36 TC MES-2
	1527:52	T+59:16 TC MECO-2	195 x -29536 x 41.87
	1530:42	T+1:02:06 TC sep
		T+1:02:08 TC avoidance
	1530:58	T+1:02:21s PMI burn
	1531:40	T+1:03:06 PM burnout	326 x -20835 x 41.86
	1543:01	T+1:12:33 PM sep
	1937	VGR pass EL1:4
	2050	Centaur pass EL1:4
1977 Aug 21	0200	VGR pass lunar orbit
1977 Aug 21	1600?	VGR exit SOI/929 at Vinf=10.14 km/s
1977 Aug 22	0824	VGR exit SOI/L1
1977 Aug 22	0300?	Centaur exit Earth SOI (929k) at Vinf = 6.93 km/s	1.02 x 3.02 AU x 3.7 deg?
1977 Aug 23	0215?	Centaur exit Earth Hill sphere per orbit soln
1977 Aug 26		Attempt to jettison IRIS cover aborted
1977 Aug 29		IRIS cover jettisoed
1977 Sep 2		Begin cruise
1977 Oct 11		TCM B-1
1978 Apr		Main radio receiver fail
1978 May 3		TCM B-2
1979 Apr 24		First Jupiter image
1979 Apr 30	1830?	Enter Jupiter sphere
1979 May 1		48M km from Jupiter
1979 May		Jupiter Observatory Phase
1979 May 26		TCM B-3
1979 Jun 27		TCM B-4
1979 Jul 8		Jupiter Near Encounter
1979 Jul 8	1313	Callisto, 214930 km C/A
1979 Jul 9	0806	Ganymede, 62130 km C/A
	0850	Max earth-rel velocity 55.91 km/s
	1843	Europa, 205720 km C/A
	2030?	Amalthea 558370 km C/A
	2229:00	Jupiter, 650178 km (721670 km C/A)
1979 Jul 9		TCM B-5 peri+2hr, 76min
1979 Jul 23		TCM B-6
1979 Aug 5		Cruise phase
1979 Sep 18	0240?	Exit Jupiter sphere
1979 Sep 23		48Mkm from Jupiter
1981 Feb 26		TCM B-7
1981 Jun 5		Saturn Observatory Phase, 77 Mkm
1981 Jun 18	2000?	Enter Saturn sphere 64.5M
1981 Jun 22		55 Mkm from Saturn
1981 Jul 19		TCM B-8
1981 Jul 31		Saturn Far Encounter 1
1981 Aug 11		Saturn Far Encounter 2
1981 Aug 18		TCM B-9
1981 Aug 25		Saturn Near Encounter
1981 Aug 23	0127	Iapetus, 908680 km C/A
1981 Aug 25	0125	Hyperion 471370 km C/A
1981 Aug 25	0937	Titan 666190 km C/A
	2258	Helene, 270000 km C/A
1981 Aug 26	0105	Dione, 502310 km C/A
	0222	Calypso, 200000? km C/A
	0234	Mimas, 309930 km C/A
	0308	Atlas, 287000 km C/A
	0319	Pandora, 107000 km C/A
1981 Aug 26	0324	Saturn, 100800 km
	0333	Prometheus, 247000 km C/A
	0345	Enceladus, 87010 km C/A
	0350	Janus, 223000 km C/A
	0406	Epimetheus, 147000 km C/A
	0415	Ring plane crossing, in G ring
	0440	Max earth-rel velocity, 61.7 km/s
	0514	Scan platform fail
	0603	Telesto, 300000 km?
	0612	Tethys, 93010 km C/A
	0629	Rhea, 645260 km C/A
1981 Aug 27		Saturn Post Encounter
1981 Sep 4	0130?	Phoebe, 2075640 km C/A
1981 Sep 28		Cruise Phase
1981 Sep 29		TCM-10
1981 Nov 2	1030?	64.5M exit Saturn SOI
1981 Nov 10		55Mkm exit Saturn SOI
1984 Nov 13		TCM-11
1985 Nov 4		Uranus Observatory Phase 103 Mkm
1985 Dec 1	0430?	69.6M enter U SOI
1985 Dec 24		TCM-12?
1985 Dec 31		Uranus SOI
1986 Jan 24		Uranus near encounter
	1530?	Titania, 365200 km C/A
	1600?	Oberon, 470600 km C/A
	1700?	Ariel, 127000 km C/A
1986 Jan 24	1730?	Miranda, 28260 km C/A
1986 Jan 24	1759	Uranus 81541 km (71000 km old) (107100 km C/A)
	1800?	Umbriel, 325000 km C/A
1986 Feb 25		Cruise phase
1986 Mar 20	0630?	Leave Uranus Sphere 69.6M
1987 Mar 13		TCM B15
1988 late		TCM B16
1988 Nov 11		TCM B17B 0.45 km/s
1989 Apr 20		TCM B17C 0.3 km/s
1989 Jun 5		Neptune Observatory Phase
1989 Jun 6	1200	N Sphere 115.2M
1989 Jun 30		Neptune SOI 87Mkm
1989 Aug 1		TCM B18 0.92 km/s
1989 Aug 6		Neptune Far Encounter
1989 Aug 21		TCM B20 0.47 km/s
1989 Aug 24		Neptune Near Encounter
	2356	Nereid, 4.6Mkm
1989 Aug 25	0253	Ring plane inbound
1989 Aug 25	0356	Neptune, 4476 (old 4905 km) (29242+-2 km C/A)
	0514	Ring plane outbound
	0910	Triton, 38360 km (39780+-20 km C/A)
1989 Aug 26		Post Encounter
1989 Oct 2		Cruise
1989 Oct 25		Leave Neptune SOI
1989 Nov 12	2000?	Leave Neptune sphere 115.2M
1990 Jan 1		Voyager Interstellar Mission
1998 Nov 12		Comms lost
1998 Nov 14		Comms restored
1998 Nov		Scan platform turned off
1999 Feb 1		OWLT 16 hr
2007 Aug 30		First helioshock pass at 84AU

Payload:

• MHW RTG

• Imaging TV cameras (2), 1500mm f/8.5 narrow angle, 200mm f/3 wide angle

• UVS Ultraviolet spectrometer 534-1701A Plasma spectrometers

• IRIS IR spectrometer/radiometer

• LEPI Low energy charged particle analyser/telescope

• Multifilter photometer 2200-7300A, 8-in, F/1.1 scope

• Triaxial fluxgate magnetometers