The Hubble is a satellite. It orbits the Earth very quickly, completing one revolution every 97 minutes. This means the Hubble moves a speed of about 5 miles per second, or 18,000 miles per hour! When the Hubble observes distant stars and galaxies, it must stay pointed in the same direction for hours at a time. In addition, it must remain stable while fighting the effects of the Earth’s gravity and the solar wind.

How does the Hubble remain stable? While the telescope is making observations, computer-controlled machines called gyroscopes keep it stable and pointed in the right direction. The Hubble requires very precise pointing to take good pictures.

The operation of the Hubble is controlled by scientists and engineers at the Space Telescope Science Institute, located near Baltimore, Maryland. The scientists, who are from all over the world, decide where they want the telescope to look, and what kind of information they want to collect. The engineers are responsible for giving commands to the satellite and making sure it stays in working order.

Hubble Space Telescope preassembly.