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ASK OCE — March 17, 2006 — Vol. 1, Issue 6

Pioneer 10 was launched on March 2nd 1972, undertaking a mission to explore Jupiter. Its mission ended 31 March 1997. Pioneer’s final, faint signal was received on 23 January 2003, more than 30 years after launch.

Launched on April 5th, 1973, Pioneer 11 followed its sister ship to Jupiter and then journeyed on to make the first direct observations of Saturn, sending back data on energetic particles in the planet’s outer heliosphere. The spacecraft’s last transmission was received September 30th, 1995. Pioneer 11 was launched as a backup spacecraft in the event that Pioneer 10 was unable to continue on its mission after passing through the hazardous Asteroid Belt. Both craft were small, spin stabilized (4.28 rpm) spacecraft powered by a Radioisotope Thermoelectric Generator (RTG).

Pioneer 10 was the first spacecraft to travel through the Asteroid Belt and the first to make direct observations and obtain close-up images of Jupiter. Known as the most remote object ever made by man through most of its mission, Pioneer 10 is now more than 8 billion miles from earth.

Pioneer 10 passed by Jupiter on December 3rd, 1973, passing within 81,000 miles of the surface of the planet. The Pioneer 10 mission paved the way for further exploration of the outer solar system by the Voyager, Ulysses, Galileo and Cassini spacecrafts.

During its encounter with Jupiter, Pioneer 10 sent back data and images of the planet and its moons, including measurements of Jupiter’s magnetosphere, radiation belts, magnetic field, atmosphere, and interior. The craft’s measurements of the intense radiation environment near Jupiter were critical to the successful designing of the Voyager and Galileo spacecraft.

Pioneer 10 will continue to drift as a ghost ship through deep space and on into interstellar space. It is heading in the direction of the star Aldebaran, the eye of the Taurus. It will take Pioneer 10 approximately 2 million years to get there.

Pioneer 11 spacecraft is currently heading toward the constellation of Aquila. It will pass near one of the stars in the constellation in about 4 million years.

On board Pioneer 10 and 11 is a plaque with a pictorial message from mankind. The gold-plated, aluminum plaque depicts the likenesses of a man and a woman including several symbols providing information about the origin of the spacecraft in the unlikely event that it is ever retrieved by interstellar travelers.

Charles Hall, the original Project Manager from 1962 to 1980, is the manager most responsible for the notable success of Pioneer. He was PM from the earliest phases of research and development to the successful implementation of the primary missions of Pioneer 6 through 13. Hall retired after Pioneer 11 passed by Saturn in 1979.

On November 18, 1999 the US Postal Service issued a stamp commemorating the Pioneer 10 spacecraft as part of its Celebrate the Century postage stamp series. A Pioneer 10 stamp was also issued in 1974.


Other milestones This Week in NASA History


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