During the NASA
Space Shuttle program, the structures at the
Launch Complex 39 pads contained a two-piece access tower system, the Fixed Service Structure (FSS) and the Rotating Service Structure (RSS). The FSS permitted access to the Shuttle via a retractable arm and a "beanie cap" to capture vented
liquid oxygen (LOX) from the
external fuel tank. The RSS contained the
Payload Changeout Room, which offered "clean" access to the
orbiter's payload bay, protection from the elements, and protection in winds up to . The FSS on Pad 39A was repurposed the top of the umbilical tower of
Mobile Launcher 2, while the FSS on 39B re-used the umbilical tower of Mobile Launcher 3. Mobile Launcher 3 would later become Mobile Launcher Platform 1 for the Shuttle. In 2011 NASA removed both the FSS and RSS from LC-39B to make way for a
new generation of launch vehicles. In 2017-2018
SpaceX removed the RSS from
LC-39A and modified the FSS for its
new series of launch vehicles. Certain rockets such as the
Delta and the
Saturn V use structures consisting of a fixed portion and a mobile portion; the former is the umbilical tower and the latter is known as the "mobile service tower" or "mobile service structure," but often referred to as a
gantry. This mobile structure is moved away from the vehicle several hours before launch.
White room in the
Launch Complex 39 white room prior to launch of
STS-125 The
white room was the small area used by
astronauts to access the spacecraft during human flights up through the
Space Shuttle program. The room takes its name from its white paint, which was used in
Project Gemini. The room was first used in
Project Mercury. Its use and white color (since Gemini) continued through subsequent programs of Apollo and the Space Shuttle. Astronauts and closeout crew made their final preparations before liftoff, such as donning
parachute packs, putting on
spacesuit helmets, and detaching portable
air-conditioning units. In 2014, NASA planned to move the White Room to a museum. As of the 2020
Crew Dragon Demo-2 mission, SpaceX began calling the equivalent area of its Crew Access Arm at LC-39A the "White Room" in recognition of the original NASA structure's significance. On the first launch attempt, NASA and SpaceX flight crew began signing their respective "meatball"
NASA insignia or SpaceX logos at the end of the Crew Access Arm, a practice which has become a tradition. ==Baikonur Cosmodrome==