The Saturn IB was an American launch vehicle commissioned by the National Aeronautics and Space Administration (NASA) for the Apollo program. It replaced the S-IV second stage of the Saturn I with the much more powerful S-IVB, able to launch a partially fueled Apollo command and service module (CSM) or a fully fueled Apollo Lunar Module (LM) into low Earth orbit for early flight tests before the larger Saturn V needed for lunar flight was ready.
The Saturn IB launched two uncrewed CSM suborbital flights to a height of 162km, one uncrewed LM orbital flight, and the first crewed CSM orbital mission (first planned as Apollo 1, later flown as Apollo 7). It also launched one orbital mission, AS-203, without a payload so the S-IVB would have residual liquid hydrogen fuel.
In 1973, the year after the Apollo lunar program ended, three Apollo CSM/Saturn IBs ferried crews to the Skylab space station. In 1975, one last Apollo/Saturn IB launched the Apollo portion of the joint US-USSR Apollo–Soyuz Test Project (ASTP). A backup Apollo CSM/Saturn IB was assembled and made ready for a Skylab rescue mission, but never flown.
Model Height: 18.75 inches