Galileo
First spacecraft to orbit an outer planet.
Galileo was an American robotic space probe that studied the planet Jupiter and its moons, as well as the asteroids Gaspra and Ida. Named after the Italian astronomer Galileo Galilei, it consisted of an orbiter and an entry probe. It became the first spacecraft to orbit an outer planet.
- field
- Space exploration
- nationality
- American
- height
- 6.15 m (20.2 ft)
- destroyed
- September 21, 2003
Lore & Background
The Jet Propulsion Laboratory built the spacecraft and managed the program for NASA, while West Germany's Messerschmitt-Bölkow-Blohm supplied the propulsion module. NASA's Ames Research Center managed the atmospheric probe, built by Hughes Aircraft Company. Spacecraft are normally stabilized either by spinning around a fixed axis or by maintaining a fixed orientation with reference to the Sun and a star; Galileo did both. One section rotated at three revolutions per minute, keeping it stable and holding six instruments that gathered data from many directions. Galileo was intentionally destroyed in Jupiter's atmosphere on September 21, 2003, to prevent contaminating any of Jupiter's moons. The spacecraft used a Mariner program design rather than a Pioneer, allowing high-resolution imaging but at greater weight. The launch was delayed by the Space Shuttle Challenger disaster and later by a faulty main engine controller and inclement weather.
Reader's Guide
Galileo's significance lies in being the first spacecraft to orbit an outer planet, providing unprecedented data on Jupiter, its moons, and asteroids Gaspra and Ida. Its dual-spin stabilization design was innovative, combining spinning and fixed-orientation methods. The mission demonstrated the feasibility of long-duration outer planet exploration and gravitational assist trajectories. Its intentional destruction in Jupiter's atmosphere set a precedent for planetary protection, avoiding contamination of potentially habitable moons. Galileo's legacy includes advancing understanding of the Jovian system and proving technologies for future deep space missions.
Did You Know?
- Galileo was named after the Italian astronomer Galileo Galilei, the first person to view Jupiter through a telescope.
- Galileo was intentionally destroyed in Jupiter's atmosphere on September 21, 2003, to prevent contaminating any of Jupiter's moons.
- The launch was delayed by the Space Shuttle Challenger disaster, a faulty main engine controller, and inclement weather.
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