Editing STS-5 (section)

== Operational status ==
The Space Shuttle was formally declared "operational" after [[STS-4]]. However, the Columbia Accident Investigation Board (CAIB), in its report on the loss with all crew aboard of ''Columbia'' during [[STS-107]] in 2003, asserted that the orbiter should never have been considered operational and that, while not intrinsically unsafe, it was in fact an experimental vehicle. The CAIB's rationale was that civilian and military aircraft that are considered operational must have been tested and proven over thousands of safe flights in their final operational configurations, whereas the shuttle had conducted under 200 flights, with continuous modification. NASA operated the Space Shuttle as an experimental vehicle for the remainder of the program.<ref>{{cite web|title=Columbia Accident Investigation Board |url=https://history.nasa.gov/columbia/Troxell/Columbia%20Web%20Site/CAIB/CAIB%20Website/CAIB%20Report/Volume%201/Part%201/chapter1.pdf|publisher=NASA|access-date=August 16, 2015}} {{PD-notice}}</ref>