Editing Service structure (section)

{{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]], a launch tower is visible in the background]]
A '''service structure''' is a permanent [[steel]] [[Scaffolding|framework]] or [[tower]] erected on a [[rocket]] [[launch pad]] that allows assembly, servicing, and crew onboarding of the [[launch vehicle]] prior to [[Space launch|liftoff]]. 

In [[NASA]] [[Space launch|launches]] at the [[Kennedy Space Center]], [[astronauts]] enter the vehicle through a type of service structure called an  "[[Umbilical cable|umbilical]] tower". Immediately before ignition of the rocket's [[Rocket engine|engines]], all connections between the tower and the craft are severed, and the connecting [[Bridge|bridges]] swing away to prevent damage to structure and vehicle. An [[elevator]] in the tower also allows maintenance crew to service the vehicle. {{Citation needed|date=October 2021}}