What is a gravity assist or a swingby for a spacecraft? I've heard about spacecraft gaining velocity from passing close to planets and being 'sling shot'-ed into a higher orbit. Where does this energy come from?

Scientists have figured out how to use the planets to speed up or slow down a spacecraft. The spacecraft is sent around the planet. It's whipped around the planet and then let go...like a slingshot you would swing around in a circle and then let go. This is why this whole process is called the slingshot method. Some people also call the slingshot method the swingby or gravity assist method.


Submitted by Mark (Maryland, USA)
Submitted by Jean-Marc (Oullins, France)
(September 3, 1998)


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