Space Probes
	Some space probes, such as Pioneer 10, fly out of our solar system and never come back. Other space probes, like the Hubble Space Telescope, stay in orbit around the same planet their whole life.

Space probes are made to conduct science experiments. They do not have people on them. Space probes have helped scientists get information about our solar system. Most probes are not designed to return to Earth. Some have landed on other planets! Others have flown past the planets and taken pictures of them for scientists to see. There are even some space probes that go into orbit around other planets and study them for a long time. The information they gather is used to help us understand the weather and other changes which happen on planets other than the Earth. This information is important in helping to plan other space missions such as the Mars Pathfinder mission and the Cassini mission. The Lander of the Pathfinder bounced onto the surface of Mars on July 4, 1997. The lander carried a robot named Sojourner. Sojourner was about the size of a microwave oven. Sojourner was given two important jobs. One was to take pictures of Mars' surface to send back to Earth. The second was to test samples of Martian rock and soil. Scientists will use information gathered by Sojourner to help them decide whether life could ever have existed on Mars. The Cassini probe to Saturn was launched on October 15, 1997. It is the biggest and most expensive probe to ever visit a planet. Scientists believe it will take Cassini 7 years to reach Saturn. Beginning in 2004, scientists hope to receive information about Saturn's rings and moons from the probe.