The space shuttle missions range widely in terms of their objectives and length. One of the main objectives of the space shuttle program was to preform scientific experiments in space; these were usually the longer missions. Other sorts of missions included launching and servicing satellites such as the Hubble Space Telescope.
The main mission in the later years of the program was to complete the International Space Station, supply the station and rotate the crew.
There were a total of 135 Space Shuttle missions, the missions did much to advance sciences and were very productive.