Editing Vandenberg Space Force Base (section)

===== Space Shuttle =====
[[File:Enterprise at Vandenberg AFB SLC-6 - DF-ST-86-09420.jpg|thumb|upright|1985 photo of Space Shuttle Enterprise (OV-101) moving toward the shuttle assembly building at Vandenberg Space Launch Complex-6 aboard its specially designed Cometto 76-wheel transporter. In the background are the payload changeout room and the payload preparation room.]]

In 1972, Vandenberg was selected as the West Coast [[Space Shuttle]] launch and landing site, but it was never used as such.

[[Vandenberg AFB Space Launch Complex 6|Space Launch Complex-6]] (SLC-6, pronounced as "Slick Six"), originally built for the abandoned [[Manned Orbital Laboratory]] project, was extensively modified for shuttle operations. Over US$4 billion was spent on the modifications to the complex and construction of associated infrastructure. The original Mobile Service Tower (MST) was lowered in height and two new flame ducts were added for the shuttle's solid rocket boosters. Additional modifications or improvements, included [[liquid hydrogen]] and [[liquid oxygen]] storage tanks, a payload preparation room, payload changeout room, a new launch tower with escape system for the shuttle crewmembers, sound suppression system and water reclamation area and a Shuttle Assembly Building were added to the original complex.

The existing 8,500-foot (2,590 m) runway and overruns on the North Base flightline were lengthened to 15,000 feet (4,580 m) to accommodate end-of-mission landings, along with construction of the [[Precision Approach Path Indicator]] (PAPI) lights/large triangle arrows at both ends of the runway. Turn-around servicing and refurbishing of the [[Space Shuttle orbiter]] would be accomplished in the adjacent Orbiter Maintenance and Checkout Facility (OMCF). The Mate-Demate Facility, to load and unload the Orbiter from the [[Boeing 747]] [[Shuttle Carrier Aircraft]] (SCA), was changed from the large structure found at Dryden Flight Research Center and Kennedy Space Center, to a transportable "erector set-like" Orbiter Lifting Frame (OLF). This facility design change was due to the possibility of needing to support a landing at a location where there was no facility to load the Orbiter onto the SCA. The OLF could be disassembled, loaded onto two C-5 aircraft, shipped to the overseas Orbiter landing site, and reassembled to load the Orbiter onto the Boeing 747. To transport the Orbiter from the OMCF (on North Vandenberg AFB) to SLC-6, the {{cvt|22|mi|km}} route was upgraded to accommodate a 76-wheeled vehicle, built by Commetto in [[Italy]] specifically to carry the Orbiter on its large flat deck utilizing the three external tank interface points, versus towing the Orbiter on its landing gear that long distance.

Modification of SLC-6 to support polar missions had been problematic and expensive.{{citation needed|date=September 2023}} SLC-6 was still being prepared for its first Shuttle launch, mission [[STS-62-A]] targeted for 15 October 1986, when the [[STS-51-L|''Challenger'' disaster]] grounded the Shuttle fleet and set in motion a chain of events that finally led to the decision to cancel all west coast shuttle launches. The orbiter transporter was sent to [[Kennedy Space Center]] in Florida after the Vandenberg AFB launch site was abandoned and was used to transport the Orbiter from the Orbiter Processing Facility to the Vehicle Assembly Building.

Persistent site technical problems and a joint decision by the Air Force and [[NASA]] to consolidate Shuttle operations at the Kennedy Space Center, following the Challenger disaster in 1986, resulted in the official termination of the Shuttle program at Vandenberg on 26 December 1989.

Had the space shuttle program been successful at [[Vandenberg Space Launch Complex 6|SLC-6]], the West Coast operation would have contrasted with that at the Kennedy Space Center by creating the orbiter stack directly on the launch pad, rather than assembling it and then moving it. Three movable buildings on rails, the Launch Tower, Mobile Service Building and Payload Changeout Room were used to assemble the Shuttle orbiter, external tank and SRBs. These buildings were designed to protect the shuttle "stack" from high winds in the area and were used during a series of "fit tests" utilizing the space shuttle [[Space Shuttle Enterprise|''Enterprise'']] in 1985.