# Service structure > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Service_structure > Markdown URL: https://mediated.wiki/source/Service_structure.md > Source: https://en.wikipedia.org/wiki/Service_structure > Source revision: 1346747651 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{short description|Structure built on a rocket launch pad to service launch vehicles}} [[File:STS-114 rollout.jpg|thumb|{{OV|103}} is carried by a [Crawler-transporter](/source/Crawler-transporter), a launch tower is visible in the background]] A '''service structure''' is a permanent [steel](/source/steel) [framework](/source/Scaffolding) or [tower](/source/tower) erected on a [rocket](/source/rocket) [launch pad](/source/launch_pad) that allows assembly, servicing, and crew onboarding of the [launch vehicle](/source/launch_vehicle) prior to [liftoff](/source/Space_launch). In [NASA](/source/NASA) [launches](/source/Space_launch) at the [Kennedy Space Center](/source/Kennedy_Space_Center), [astronauts](/source/astronauts) enter the vehicle through a type of service structure called an "[umbilical](/source/Umbilical_cable) tower". Immediately before ignition of the rocket's [engines](/source/Rocket_engine), all connections between the tower and the craft are severed, and the connecting [bridges](/source/Bridge) swing away to prevent damage to structure and vehicle. An [elevator](/source/elevator) in the tower also allows maintenance crew to service the vehicle. {{Citation needed|date=October 2021}} ==Kennedy Space Center== During the NASA [Space Shuttle program](/source/Space_Shuttle_program), the structures at the [Launch Complex 39](/source/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](/source/liquid_oxygen) (LOX) from the [external fuel tank](/source/external_fuel_tank). The RSS contained the [Payload](/source/Payload) Changeout Room, which offered "clean" access to the [orbiter's](/source/orbiter's) payload bay, protection from the elements, and protection in winds up to {{convert|60|kn|km/h}}.{{Citation needed|date=October 2021}} The FSS on Pad 39A was repurposed the top of the umbilical tower of [Mobile Launcher](/source/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. {{Citation needed|date=March 2025}} In 2011 NASA removed both the FSS and RSS from LC-39B to make way for a [new generation of launch vehicles](/source/Artemis_program). In 2017-2018 [SpaceX](/source/SpaceX) removed the RSS from [LC-39A](/source/LC-39A) and modified the FSS for its [new series of launch vehicles](/source/SpaceX_launch_vehicles).{{Citation needed|date=October 2021}} Certain rockets such as the [Delta](/source/Delta_(rocket_family)) and the [Saturn V](/source/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 === [[File:STS white room.jpg|thumb|Closeout crew members help astronaut [Andrew Feustel](/source/Andrew_Feustel) in the [Launch Complex 39](/source/Launch_Complex_39) white room prior to launch of [STS-125](/source/STS-125)]] The '''white room''' was the small area used by [astronauts](/source/astronauts) to access the spacecraft during human flights up through the [Space Shuttle program](/source/Space_Shuttle_program). The room takes its name from its white paint, which was used in [Project Gemini](/source/Project_Gemini). The room was first used in [Project Mercury](/source/Project_Mercury). Its use and white color (since Gemini) continued through subsequent programs of Apollo and the Space Shuttle.{{Cite web | title=All Aboard! Astronauts Climb into Dragon Endeavour - NASA | url=https://www.nasa.gov/blogs/spacestation/2024/03/03/all-aboard-astronauts-climb-into-dragon-endeavour/ | access-date=2025-08-22 | website=www.nasa.gov | date=3 March 2024 }} Astronauts and closeout crew made their final preparations before liftoff, such as donning [parachute](/source/parachute) packs, putting on [spacesuit](/source/spacesuit) helmets, and detaching portable [air-conditioning](/source/air-conditioning) units.{{cite book|last=Burgess|first=Colin |title=Fallen astronauts: heroes who died reaching for the moon|year=2003|publisher=Bison Books|isbn=0-8032-6212-4}} In 2014, NASA planned to move the White Room to a museum.{{cite news |title=NASA signs over historic Launch Pad 39A to SpaceX |url=http://www.collectspace.com/news/news-041414a-launch-pad-39a-spacex.html |newspaper=collectSpace |date=2014-04-14 |access-date=2021-10-01 |archive-date=2014-08-24 |archive-url=https://web.archive.org/web/20140824060434/http://collectspace.com/news/news-041414a-launch-pad-39a-spacex.html |url-status=live }} As of the 2020 [Crew Dragon Demo-2](/source/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.{{Cite web | title=NASA's SpaceX Crew-10 Arrives at Launch Complex 39A - NASA | url=https://www.nasa.gov/blogs/commercialcrew/2025/03/14/nasas-spacex-crew-10-arrives-at-launch-complex-39a-2/ | access-date=2025-08-22 | website=www.nasa.gov | date=14 March 2025 }} On the first launch attempt, NASA and SpaceX flight crew began signing their respective "meatball" [NASA insignia](/source/NASA_insignia) or SpaceX logos at the end of the Crew Access Arm, a practice which has become a tradition.{{Citation needed|date=December 2022}} ==Baikonur Cosmodrome== Similarly, Soviet-and Russian-designed service structures such as those at [Baikonur Cosmodrome](/source/Baikonur_Cosmodrome) [Site 31](/source/Baikonur_Cosmodrome_Site_31) feature rotating crane-like "tower arms" that stand upright to service and secure the vehicle. The tower arms then pivot outward away from the rocket at launch.{{Cite web | title=MetOp on the launch pad – Earth observation launch campaigns | url=https://blogs.esa.int/eolaunches/2012/09/14/metop-on-the-launch-pad/ | access-date=2025-08-22 | website=blogs.esa.int}} ==References== {{reflist}} {{Kennedy Space Center}} {{Apollo program hardware}} {{Space Shuttle}} Category:Rocket launch technologies Category:Apollo program hardware Category:Space Shuttle program --- Adapted from the Wikipedia article [Service structure](https://en.wikipedia.org/wiki/Service_structure) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Service_structure?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.