Richard Dawkins, The Magic of Reality.
Thursday, 27 April 2017
Quotes 2017 #118
"Space engineers use something called the slingshot effect to
improve the fuel economy of their rockets. The Cassini space probe,
which was designed to visit the distant planet Saturn, traveled there by
what seems like a round-about route, but was actually cunningly planned
to exploit the slingshot effect. Using far less rocket fuel than would
have been needed to fly directly to Saturn, Cassini borrowed from the
gravity and orbital movement of three planets on
the way: Venus (twice), then a return swing around Earth, then a final
mighty heave from Jupiter. In each case it fell around the planet like a
comet, gaining speed by hanging onto its gravitational coat tails as
the planet whizzed around the sun. These four slingshot boosts hurled
Cassini out towards the Saturn system of rings and 62 moons, from where
it has been sending back stunning pictures ever since."