The U.S. Air Force's fourth mystery mission of its X-37B space plane launches on May 20, 2015. How long the mission will last, and its exact purpose, is a mystery. See photos from the mission here.
The Hubble Space Telescope has been wowing space fans with amazing cosmic views for 25 years, but only because of repairs and upgrades by visiting astronauts. See the tools astronauts used to fix and repair the Hubble Space Telescope.