The first launch from the Mobile Launcher Platform-3 (MLP-3) (formerly called the Mobile Launcher-1 or ML-1) was the maiden flight of the Saturn V, and the first launch from LC-39, Apollo 4. Following this, it was used for two crewed Apollo launches: Apollo 8 and Apollo 11. After NASA decided to move Saturn IB launches from LC-34 to LC-39B, the ML-1 was modified by the addition of a structure known as the "Milkstool", which allowed the Saturn IB to use the same Launch Umbilical Tower as the much larger Saturn V. Three manned flights to Skylab, and the Apollo launch for the Apollo-Soyuz Test Project, were conducted from the ML-1 using the "Milkstool".