Pioneer 10

  1972-012A

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The Pioneer F (Pioneer Jupiter) payload was an entirely new design. The central bus was dominated by a large communications antenna and two booms holding nuclear RTGs which supplied electrical power. The first spacecraft to head to the outer planets, the Pioneer F and G probes were built by TRW for NASA-Ames. Instead of solar panels, they carried 4 SNAP-19 radioisotope thermoelectric generators using plutonium decay to generate electrical power.

Pioneer 10 was launched at 0149:04 on 1972 Mar 3 by Atlas Centaur from Cape Kennedy, Launch Complex 36A. The Atlas separated at 0153:10 and the Centaur ignited at 0154 on a single burn, ending at 0200:39. Centaur AC-27 separated at 0201, leaving Pioneer 10 and its Star 37E kick motor in solar orbit. The kick motor fired for 45s at 0202 and separated at 0204. The experiments were switched on at 0215. Pioneer 10 passed lunar orbit at 1500 on Mar 3. Trajectory correction maneuvers were carried out to refine the orbit: TCM-1A and 1B at 1219 and 1930 on Mar 7, TCM-2A and 2B at 2202 on Mar 23 and 1202 on Mar 24, and TCMs on Sep 19 and 1973 Jun 20.

TCM-1 moved encounter earlier by 9 hr; TCM-2 moved it later by 2.5 hr and moved the path 6400 km closer to Jupiter.

The Jupiter encounter phase began on 1973 Nov 6, with the bow shock crossing coming on Nov 26. Pioneer 10 passed Callisto at 1390000 km on Dec 3 at 1226*, Ganymede at 446000 km on Dec 3 at 1356*, Europa at 599000 km at 1526*, and Io at 357000 km at 1956*. Closest approach to Jupiter was at 2325:05* on Dec 3, at a distance of 130400 km. On Dec 12-18, Pioneer 10 left the Jovian magnetosphere and headed out to the stars. It passed the orbit of Uranus on 1979 Jul 11, Neptune in 1983 Jun, and by 1992 Oct 9 was 55 AU from the Sun.

At the end of 1996, Pioneer 10 was still operating, with the charged particle instrument, Geiger Tube Telescope, and UV Photometer operating for part of each month. Funding for tracking the spacecraft was stopped and the last official science data was obtained on 1997 Mar 31, although the probe would still be used for deep space tracking training exercises by the Lunar Prospector control center, and some science data from the Iowa Geiger Tube, the Chicago particle instrument, and the doppler radio science experiment were returned into 1998. It was still being operated in early 1999 as part of the Lunar Prospector controller training program.

Pioneer 10
Date	Time	Event	Orbit
1972 Mar 3	0149:04	Launch by Atlas Centaur
	0153:10	Atlas sep
	0154	Centaur MES
	0200:39	Centaur MECO	1537.96 152 x 75361 x 31.48
	0201	Centaur sep
	0202	Star 37E burn, 45s
	0202	Star 37E burnout 13.896 km/s	200 x -22505? x 31.5
	0204	Star 37E sep	186 x -22379 x 31.48
	0215	Experiments on
	0307	Pass GEO
	1313	Pass lunar orbit
1972 Mar 4
	0536	Pass 929000 km sphere
	2245	Pass L1 distance
1972 Mar 7	1219	TCM-1A
	1930	TCM-1B tot 14m/s, B=140000 km
1972 Mar 23	2202	TCM-2A
1972 Mar 24	1202	TCM-2B
1972 Sep 19		TCM
1973 Jun 20		TCM
1973 Oct 1		Enter Jovian sphere
1973 Nov 6		Jupiter encounter
1973 Nov 26		Bow shock
1973 Dec 3	1441	Callisto, 1390000 km
	1611	Ganymede, 446000 km
	1741	Europa, 599000 km
	2211	Io, 357000 km
1973 Dec 4	0139:24	Jupiter, 130400 km
	0249	Max Earth-rel vel 72.27 km/s
1973 Dec 5	0000	1.6 M km from Jupiter
1973 Dec 14		10 Mkm from Jupiter
1973 Dec 18		Last magnetosphere exit
1974 Feb 12		Leave Jovian sphere
1979 Jul 11		Passed orbit of Uranus
1983 Jun		Passed orbit of Neptune
1992 Oct 9		55AU from Sun
1996 Nov 1		66.26AU from Sun
1997 Mar 31	1945	Science mission support ends
1997 Aug 9		Precession maneuver
1998 Feb 2		Precession maneuver
1999 Jul 10		Precession maneuver
2000 Mar 21		Contact
2000 Jul 8		Precession maneuver
2000 Aug 19		Contact
2001 Jan		End of contact
2001 Apr 28		Contact regained
2002 Mar 1		Contact
2003 Jan 22		Last signal
2003 Jan 25		Contact support ended