Pioneer X
pioneer10.jpg (65526 bytes)
Source: Space History
p10plaque.jpg (60171 bytes)
Source: Space History

Pioneer X reconstructed full-scale model

Following the only partially successful flight of the spin-stabilized Pioneer IV past the moon in March, 1959, several studies were conducted to determine the feasibility of designing similar longer-lived spacecraft to explore interplanetary space for extended periods of time. Between 1965 and 1968 Pioneers 6 through 9 were launched into orbit around the sun in orbits between Venus and Mars. During this time further discussions were held on the possibility of sending a spin-stabilized Pioneer-class space probe to the outer planets. In February 1969 a mission to the planet Jupiter was approved, the Pioneer Project Office of NASA/Ames Research Center was assigned the task of managing the project and the TRW Systems Group (formerly Space Technology Laboratories) was selected to design and construct two identical spacecraft for launch in the 1972-73 time period.

The objectives set for what would become Pioneers 10 and 11 were: 1) to explore the interplanetary medium beyond the orbit of Mars, 2) to investigate the nature of the asteroid belt to learn more about the conditions there, especially if it posed a hazard to spacecraft bound for the outer planets 3) to explore the environment of Jupiter. Later these objectives were extended to include the study of interplanetary space to extreme distances and the use of gravity assist, using Jupiter's gravitational field as a whip to propel the craft beyond Jupiter and into the realm of the outermost planets.

Pioneer 10 was launched from the Kennedy Space Center on 3 March 1972 on a "direct ascent trajectory", that is, without first being placed in a "parking orbit" around the earth. Just eleven hours after launch, the spacecraft passed the orbit of the moon and headed into interplanetary space. In July, Pioneer 10 entered the asteroid belt. Seven months later it emerged unscathed. Pioneer 10's Jupiter encounter occurred in early December 1973. Valuable data were returned during transit. Especially significant were measurements of the intense magnetic fields that surround Jupiter and their associated radiation belts, observations of the temperatures and structure of Jupiter's upper atmosphere, and the return of color images of the planet, including Jupiter's Red Spot. Images from the scanning photo-polarimeter were downloaded and stored on magnetic tapes which were flown to Tucson for processing by the Optical Sciences Center at the University of Arizona. A 70-hour time lag was typically involved for full image processing.

Since its Jupiter encounter, Pioneer 10 has continued its journey outward. It will eventually to leave the solar system entirely. Because its power sources are long-lived radioisotope thermo-electric generators, Pioneer 10 continues to operate and send back data, including measurements of the solar magnetic field. In July, 1981 Pioneer 10 passed the 25 astronomical unit (AU) milestone, or 2.3 billion miles from the Sun. (One AU equals the mean distance between the sun and the earth). Until February, 1998, Pioneer 10 was the most distant space probe launched from earth. But in that month, Voyager 1 became the most distant space probe, at 6.5 billion miles (10.4 billion kilometers) from Earth. The two are headed in almost opposite directions away from the Sun.

NASA officially ended the Pioneer 10 mission on 31 March 1997. However, NASA's Research Center at Moffett Field, CA, still receives intermittent data from Pioneer and uses these data as part of a training program for flight controllers of the Lunar Prospector spacecraft in orbit around the Moon.

The object in the collection is a full-scale model constructed from spare parts and is identical to the flight configuration of Pioneer 10. The reconstruction was performed by TRW Space Vehicles Division, working as a contractor for the Jet Propulsion Laboratory/NASA and for NASA/Ames. RTG power unit casings were provided by Teledyne Energy Systems. Transfer of the object was made from NASA to the Smithsonian in 1976 and physical transfer was made in January 1977. Pioneer 10 has been on display in Milestones of flight since then.

Antenna Diameter: 2.7 meters (9 feet)
Length: 2.9 meters (9.5 feet)
Weight: 258 kilograms (568 pounds)

AN/DHD 8/98

More Information:
Pioneer 10 (replica) on display in Milestones of Flight gallery.
Civilian Space
Navigation, and Control
in Space
and Missiles
Home Page

This page updated: 08/18/99
Author: Space History Division
E-mail Inquiries

©1995-2000 Smithsonian, National Air and Space Museum
Copyright Information