Twenty-six years ago Galileo became the first probe to orbit Jupiter. It was launched in 1989 with the intent to study Jupiter and its 4 moons: Io, Europa, Ganymede and Callisto. It would take six years to reach the big red planet.
Galileo’s journey to Jupiter
The journey was meant to happen in 1986, with a rocket powerful enough to get from Earth to Jupiter. However, due to safety issues the launch was postponed until 1989. A less powerful booster rocket was attached to Galileo- however it wasn’t powerful enough to fly to Jupiter. Instead, a technique called the gravitational slingshot was used. This technique allows a spacecraft to fly into the orbit of other planets and use their gravity to increase the spacecraft’s speed. Like a slingshot (hence the name gravitational slingshot) the spacecraft is then propelled into space. Using this technique Galileo flew by Venus, swinging past Earth twice to create enough momentum to propel itself to Jupiter! It took six years for the spacecraft to arrive into Jupiter’s atmosphere- which it did at a speedy 100,000 miles per hour (mph).
Galileo spent eight years orbiting Jupiter and its moons. During its trip it made many discoveries, which it transmitted back to Earth. Amongst them is that Europa has an ocean below its surface with more water than found on Earth. It was also uncovered Ganymede is the first moon to have its own magnetic field, and that Io’s volcanoes are 100 times more active than those on earth.
During its eight year tenure, Galileo made 34 trips around Jupiter. The spacecraft traveled more than 2.8 billion miles before it was purposefully crashed into Jupiter after it ran low on fuel. “We’ve gained a steppingstone into the future of space exploration,” said Dr. Torrance Johnson, Galileo project scientist.
For an overview of the Galileo mission, click here to look at NASA’s website.