Deployed April 25, 1990 from the space shuttle Discovery, Hubble barely skims the Earth's atmosphere, orbiting just 380 miles above our planet. It is the size of a school bus and looks like a five-story tower of stacked silver canisters. Each canister houses important telescope equipment: the focusing mirrors, computers, imaging instruments, and pointing and control mechanisms. Extending from the telescope are solar panels for generating electricity and antennas for communicating with operators on the ground. It is named after American astronomer Edwin Powell Hubble, who among other achievements, discovered in 1929 that the universe is expanding.

Get more information about the Hubble Telescope.