In 1961, President Kennedy proposed to Congress the goal of landing a man on the Moon by the end of the decade.

The Mobile Launchers were then modified for the Saturn IB rocket, by adding a "milk-stool" extension platform to the launch pedestal, so that the S-IVB upper stage and Apollo spacecraft swing arms would reach their targets.

[7] The LH2, LOX, and water tanks used for the sound suppression system are the only structures left from the Space Shuttle era.

[8][9][10] In 2014, NASA announced that it would make LC-39B available to commercial users during times when it is not needed by the Space Launch System.

[12] However Northrop Grumman, who absorbed Orbital ATK in June 2018,[13] cancelled the development of OmegA in September 2020 before any launches had taken place; SLS will therefore remain the only user of LC-39B for the foreseeable future.