Hubble Space Telescope be kept in a clean room, powered up and purged with nitrogen, until a launch could be rescheduled. This costly situation (about per month) pushed the overall costs of the project even higher. This delay did allow time for engineers to perform extensive tests, swap out a possibly failure-prone battery, and make other improvements. Furthermore, the ground software needed to control Hubble was not ready in 1986, and was barely ready by the 1990 launch. Eventually, following the resumption of shuttle flights in 1988, the launch of the telescope was scheduled for 1990. On April 24, 1990, successfully launched the
Space Shuttle Atlantis Space Shuttle Atlantis Space Shuttle "Atlantis" (Orbiter Vehicle Designation: OV‑104) is a Space Shuttle orbiter vehicle belonging to the National Aeronautics and Space Administration (NASA), the spaceflight and space exploration agency of the United States. Constructed by the Rockwell International company in Southern California and delivered to the Kennedy Space Center in Eastern Florida in April 1985, "Atlantis" is the fourth operational and the second-to-last Space Shuttle built. Its maiden flight was STS-51-J from 3 to 7 October 1985. "Atlantis" embarked on its 33rd and final mission, also the final mission of a space shuttle, STS-135, on 8 July 2011.