Pioneer 10

Lore & Background

Pioneer 10 was launched on March 3, 1972, aboard an Atlas-Centaur rocket from Cape Canaveral. During the mission, its scientific instruments investigated the asteroid belt, the environment of Jupiter, the solar wind, cosmic rays, and the outer heliosphere. The spacecraft was built around a hexagonal satellite bus with a 2.74 m diameter parabolic high-gain antenna and was spin-stabilized about the antenna axis. The spacecraft carried 36 kg of liquid hydrazine monopropellant for attitude control and trajectory correction. The last signal from Pioneer 10 was received on January 23, 2003, after declining electrical power from its RTGs left the spacecraft unable to operate its radio transmitter. At that time, it was about 80 AU (12 billion km) from Earth.

Reader's Guide

Pioneer 10 was the first spacecraft to traverse the asteroid belt and the first to explore Jupiter, providing the initial close-up images and data of the planet and its environment. Its mission demonstrated that spacecraft could survive the asteroid belt and the intense radiation around Jupiter, paving the way for subsequent missions such as Pioneer 11 and the Voyager program. The spacecraft also became the first of five artificial objects to achieve escape velocity from the Solar System, and its long-lived RTGs allowed it to continue transmitting data from the outer heliosphere for over 30 years. The last signal was received in 2003, when the probe was about 80 AU from Earth. The mission's design and findings informed the planning and design of the Voyager program, and a backup spacecraft, Pioneer H, is on display at the National Air and Space Museum.

Did You Know?

• Pioneer 10 was originally designated Pioneer F before launch.
• It was the first spacecraft to traverse the asteroid belt.
• The last signal from Pioneer 10 was received on January 23, 2003, when it was about 80 AU from Earth.