NASA astronauts Steven Smith and John Grunsfeld perform a spacewalk during a December 1999 mission of the space shuttle Discovery to service the Hubble Space Telescope.

Hubble flew into orbit on April 24, 1990, aboard Discovery. The first major optical telescope to be placed in space, Hubble is currently located about 340 miles above Earth’s surface where it completes 15 orbits per day — one approximately every 95 minutes. The satellite moves at the speed of about five miles per second, fast enough to travel across the United States in about 10 minutes.

Here's a small sampling of some of the dazzling images captured by Hubble that have changed the way we view the universe.