<P> Several planned missions of the Apollo manned Moon landing program of the 1960s and 1970s were canceled for a variety of reasons, including changes in technical direction, the Apollo 1 fire, hardware delays, and budget limitations . After the landing by Apollo 12, Apollo 20, which would have been the final manned mission to the Moon, was canceled to allow Skylab to launch as a "dry workshop" (assembled on the ground). The next two missions, Apollos 18 and 19, were later canceled after the Apollo 13 incident and further budget cuts . Two Skylab missions also ended up being canceled . Two complete Saturn Vs ended up going unused and are currently on display in multiple locations around the United States . </P> <P> In September 1962, NASA planned to make four manned low - Earth - orbital test flights of partially equipped Block I Command / Service Modules (CSM) using the Saturn I launch vehicle, designated SA - 11 through SA - 14, in 1965 and 1966 . However, the limited payload capacity of the Saturn I compared to the uprated Saturn IB would have severely limited the systems carried, and thus the testing value of these flights . Therefore, NASA canceled these flights in October 1963, and replaced them with two manned Saturn IB missions, designated AS - 204 and AS - 205 . These would be followed by the first unmanned flight of the Lunar Module (LM) on AS - 206, then the third manned mission, designated AS - 207 / 208, would use AS - 207 to launch the crew in an improved Block II CSM, which would rendezvous and dock with the LM launched unmanned on AS - 208 . </P>

How many apollo missions were there supposed to be
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