How do space vehicles get to different planets? What kind of computers or equipment guide them there? - question from name withheld
Most interplanetary space vehicles are first launched into a "parking" orbit around Earth. A vehicles then picks
up energy (or speed) by using Earth's gravity (and sometimes the gravity of other planets as well) to "slingshot"
it away from Earth and towards its final destination. When the vehicle finally arrives at the planet, it does
just the opposite and uses the planet's gravity to "capture" the spacecraft and bring it into a parking orbit
around the planet. As far as the computers and equipment go, you might be surprised to find out that most of the
computers used to guide these vehicles have only a mere fraction of the computing power in the computer you're
looking at right now. I can't speak to the exact nature of the computers themselves, but as far as the guidance
systems go, each spacecraft has a variety of sensors that help it determine how it is oriented in 3-dimensional
space and how fast it is going. There are also a number of ground based tracking systems that help determine that
same information.
- answer by Aaron Brown, 24 June 2001
