"The year 1986 was to be the biggest year for the Space Shuttle yet. A total of 15 flights were planned: including the launch of the Hubble Space Telescope, the Gailieo and Ulysses space probes, and the first launch from Vandeburg Air Force Base in California. By 1988, NASA was hoping to launch 24 shuttle missions per year. (The most ever achieved was nine. The shuttle cannot fly much more than this in a year.) But the events of a cold day in January would forever alter these plans." http://www.gcs.k12.in.us/bholt/Challenger%20Disaster%20Facts.htm