Welcome to the Pioneer Project Home Page.

Launched on 2 March 1972, Pioneer 10 was the first spacecraft to travel through the Asteroid belt, and the first spacecraft to make direct observations and obtain close-up images of Jupiter. Famed as the most remote object ever made by man, Pioneer 10 is now 6.5 billion miles away. The spacecraft made valuable scientific investigations in the outer regions of our solar system until the end of its mission on 31 March 1997. Pioneer 10 is headed towards the constellation of Taurus (The Bull). It will take Pioneer over 2 million years to pass by one of the stars in the constellation.

Launched on 5 April 1973, Pioneer 11 followed its sister ship to Jupiter (1974), made the first direct observations of Saturn (1979) and studied energetic particles in the outer heliosphere. The Pioneer 11 Mission ended on 30 September 1995, when the last transmission from the spacecraft was received. Its electrical power source exhausted, the spacecraft could no longer operate any of its scientific instruments, nor point its antenna toward Earth. The spacecraft is headed toward the constellation of Aquila (The Eagle), Northwest of the constellation of Sagittarius. Pioneer 11 may pass near one of the stars in the constellation in about 4 million years.

For additional information on Pioneer 10 & 11, and the current status of the missions, look at:

Mission Descriptions | Mission Status | Images | Flight Path

Descriptions of Pioneer 10 and 11 science instruments and science data sets are available for the following:

Geiger Tube Telescope
Plasma Analyzer Instrument

Pioneer Project History

The Pioneer 10 & 11 Spacecraft Missions are two of a series of eight spacecraft missions managed by the Pioneer Project Office at NASA, Ames Research Center. The following is a brief description of the other Pioneer Missions.

Pioneer 6-9

Pioneers 6-9 were launched into Solar orbit between 1965 and 1968. Their prime mission completed years ago, the spacecraft were then tracked only occasionally.

Pioneer 6 was launched on 16 December 1965. Some time after 15 December 1995 (almost 30 years after it was launched) the primary transmitter (TWT) failed. During a track on 11 July 1996 the spacecraft was commanded to switch to the backup TWT, and the downlink signal was re-acquired. The spacecraft and a few of the science instruments were again functioning. Pioneer 6 has most recently been tracked on 6 October 1997 as part of a training program for flight controllers of the Lunar Prospector (now orbiting the Moon).

Pioneer 7 was launched on 17 August 1966. It was last tracked successfully on 31 March 1995. The spacecraft and one of the science instruments were still functioning.

Pioneer 8 was launched on 13 December 1967. Its primary TWT failed several years ago, but on 22 August 1996 the spacecraft was commanded to switch to the backup TWT, and the downlink signal was re-acquired. The spacecraft and one of the science instruments were again functioning.

Pioneer 9 was launched on 8 November 1968. The spacecraft failed in 1983.

Pioneer Venus

The Pioneer Venus Orbiter spacecraft was launched on 20 May 1978. It orbited the planet Venus for 14 years until it entered the Venus atmosphere on 8 October 1992 and was destroyed.

The Pioneer Venus Multiprobe spacecraft was launched on 8 August 1978. Three small probes, one large probe, and the spacecraft bus entered the Venus atmosphere on 9 December 1978.

For a description of these Pioneer Missions, see Pioneer History

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This page last modified 8 July 1998.

Project Manager: Dr. Lawrence Lasher (e-mail:llasher@mail.arc.nasa.gov)

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