NASA's Galileo Mission sought to analyze Jupiter and its moons.
Since its inception in 1958, the National Aeronautics and Space Administration stands as an emblem of American scientific and exploratory progress and prowess. Created just one year after the Soviet Union made Sputnik the first man-made object to enter space, NASA landed a man on the moon only 11 years later. NASA's Galileo Mission represented another crucial step in space exploration.
Galileo Mission Goals
The Galileo Mission was a large endeavor for NASA. The program consisted of two pieces: the Galileo Orbiter and the Galileo Probe. The goals of the mission were to analyze the makeup of the Jovian atmosphere using an atmospheric probe, as well as to examine the makeup of the Galilean moons with an orbiter. Launched in October 1989, the mission lasted approximately 14 years, with the official mission end date in September 2003. It took the unmanned spacecraft carrying the orbiter and probe more than five years to reach Jupiter in 1995.
Mission
In October 1989, the Galileo Mission began when a inertial upper-stage (IUS) rocket blasted the Galileo Probe and Orbiter out of Earth's orbit. This rocket set the Galileo Probe and Orbiter on a VEEGA (Venus-Earth-Earth Gravity Assist) trajectory. The VEEGA trajectory used the gravitational pulls of Venus and Earth to give it enough momentum to reach Jupiter. The Galileo Orbiter studied Earth, Venus and Earth's moon before heading toward Jupiter. During VEEGA, NASA scientists were also able to study the asteroids Gaspra and Ida. The mission was the first to discover a satellite of an asteroid, which was Ida's moon, Dactyl. Another space exploration first was when the orbiter viewed fragments of a comet, Shoemaker-Levy 9, impacting a planet, Jupiter.
Probe
Although the previous scientific explorations reaped much information, the true aim of the mission was Jupiter and the Galilean moons. In December 1995, the Galileo Probe separated from the Galileo Orbiter; this occurred 147 days before the probe's entry into Jupiter's atmosphere. This was the first time a descent probe was used to analyze the Jovian atmosphere. The Galileo Probe entered Jupiter's atmosphere and took measurements on the atmospheric makeup, wind speed, electromagnetic readings, temperatures, cloud patterns and pressure. The Galileo Probe analyzed visible and infrared light data. During its descent, Jupiter's intense pressures and temperatures destroyed the probe, but not before valuable information was sent back to Earth for analyzing.
Orbiter
The Galilean moons are the four largest moons of Jupiter. They were discovered by the astronomer Galileo in 1610. The Galileo Orbiter took a range of measurements of the Galilean moons: Io, Europa, Ganymede and Callisto. The orbiter took physical, gravitational, magnetic and atmospheric measurements of these moons. The Galileo Orbiter also investigated the makeup of the Jovian atmosphere and ionosphere. This mission with the orbiter lasted approximately two years.
NASA
In 2003, NASA decided to purposely destroy the Galileo Orbiter. The orbiter had just about run out of fuel and that would make it inoperable. After the surprising discovery of a likely subsurface ocean on the moon Europa, NASA did not want the orbiter to plunge into and pollute this ocean. So NASA sent the orbiter on a collision course with Jupiter's atmosphere. NASA obtained much valuable information about Jupiter, the Galilean moons, the solar system, Earth, Venus and Earth's moon. The Galileo Mission was a valuable project for NASA, coming just before the Mars Explorative Rover Mission, launched in 2003.
Tags: Galileo Mission, Galileo Orbiter, Galileo Probe, Galilean moons, Jovian atmosphere, Jupiter atmosphere
