SLC-6, part of Vandenberg's "South Base," was originally part of the Sudden Ranch, prior to its purchase by the
U.S. Air Force in the mid-1960s under the law of
eminent domain. In addition to the ranch, the
Point Arguello Light was based there, which in 1967 was replaced by an automated light. There was also the Point Arguello
LORAN station, de-established 31 December 1979.
Titan (1966–1969) No
Titans were launched from SLC-6. After purchase of south base, the Air Force started construction of the SLC-6 facility on 12 March 1966, to support launches of a
Titan IIIM for the
Manned Orbiting Laboratory (MOL). After significant construction work was completed, the MOL program was cancelled on 10 June 1969, so further work on SLC-6 stopped as the facility was placed in
mothball status. In 1972, Vandenberg AFB was chosen as the western launch site for Air Force shuttle launches. Use of SLC-6 was approved in 1975, and re-construction of the former MOL launch facility occurred between January 1979 and July 1986 as SLC-6 was rebuilt to accommodate the space shuttle. At the launch pad, two buildings, the Shuttle Assembly Building and the Mobile Service Tower would envelop the access tower allowing the spacecraft to be stacked right on the launch pad. In all, over $4 billion were spent on the modifying SLC-6 for the Space Shuttle. 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 crew members, sound suppression system and water reclamation area and a Shuttle Assembly Building were added to the original complex. SLC-6 was declared operational during acceptance ceremonies held on 15 October 1985. However, much additional work and testing was still required. The inaugural polar-orbit flight, designated
STS-62-A and using with Shuttle veteran
Robert Crippen as commander, was planned for 15 October 1986. However, the
Challenger disaster of 28 January 1986 grounded the Shuttle fleet as efforts were concentrated on recovery and returning the program to flight after a two-year hiatus. On 31 July 1986, Secretary of the Air Force
Edward C. Aldridge, Jr., announced that Vandenberg's Space Shuttle program would be placed in "operational caretaker status", six months after the Space Shuttle
Challenger accident. A few months later, however, SLC-6 was placed in "minimum caretaker status" on 20 February 1987. Eventually, on 13 May 1988, Secretary Aldridge then directed the Air Force to transfer Space Shuttle assets at Vandenberg to other organizations (specifically, the Kennedy Space Center) by 30 September 1989, the end of the fiscal year. The work was completed 10 days early on 20 September, when SLC-6 was placed in mothball status. The Orbiter Lifting Fixture was relocated to
United States Air Force Plant 42 where the orbiters were built and refurbished in
Palmdale, California, before the delivery of the in 1991. Previously, the orbiters were trucked to Armstrong Flight Research Center at Edwards Air Force Base, about away, which took about 10 hours. The Orbiter Lifting Fixture was dismantled in 2008. The Orbiter Transport System was sent to KSC where it was used to move orbiters between the Orbiter Processing Facility and the Vehicle Assembly Building. The vehicle was purchased by SpaceX in 2014 for $37,075. Instead, USAF continued flying military polar orbit satellites using the
Titan 34D and later
Titan IV rockets from
SLC-4E at Vandenberg.
Athena (1994–1999) Four
Athena missions flew from SLC-6, from 1995 to 1999. In the early 1990s,
Lockheed Missiles and Space Company began studies on the prospect of a new family of small launch vehicles for commercial and other users. Lockheed eventually approved the development of the
Lockheed Launch Vehicle (LLV) program in January 1993. After the merger of Lockheed with
Martin Marietta, it was renamed
Athena. After another contract was issued in 1994 by the Air Force, modification work began on the existing SLC-6 shuttle launch mount for a small "milkstool" platform to be located over one of the two exhaust ducts originally intended for one of the large solid rocket boosters. The first operational launch from SLC-6 occurred on 15 August 1995, involving the Lockheed-Martin Launch Vehicle I (LMLV-1). Unfortunately, LMLV-1 was terminated in mid-flight after uncontrolled oscillations of the rocket were detected. This resulted in the loss of the vehicle and the payload. The cause of the mishap was later determined to be a guidance system failure coupled with overheating of the booster's first stage steering mechanism. The payload on board was GEMstar 1, a small communications satellite manufactured by CTA, Inc. for the Volunteers in Technical Assistance (VITA), a non-profit organization. After some hardware redesign and testing, a newly rechristened
Athena I successfully launched NASA's
Lewis satellite into orbit from SLC-6 on 22 August 1997. Part of NASA's Small Spacecraft Technology Initiative (SSTI) and "Mission to Planet Earth" program. Another launch, on 24 September 1999, was successful as an
Ikonos satellite operated by
Space Imaging (later acquired by
ORBIMAGE to form
GeoEye) was successfully placed into a polar orbit using an Athena 2 booster.
Delta IV (1999–2022) Ten
Delta IV rockets were launched from SLC-6. With the advent of the Delta IV in the late 1990s,
The Boeing Company received a lease from the Air Force on 1 September 1999, to modify SLC-6 once again to launch Boeing's
Delta IV. Some of the Shuttle-specific components at SLC-6 were removed, such as the mobile Payload Changeout Room, but the Assembly Building, Mobile Service Tower, Launch Tower,
flame deflection trenches and
sound suppression system and some other shuttle-oriented equipment were retained and made compatible for the new Delta IV rocket. The launch vehicle's
Common Booster Core and associated flight hardware was transported from the Boeing factory in
Decatur,
Ala., to Vandenberg aboard the cargo vessel that docked just south of SLC-6 at the same location originally constructed for receiving and offloading space shuttle external tanks. Boeing developed the Delta IV class of vehicles as its entrant in the Department of Defense's
Evolved Expendable Launch Vehicle (EELV) program. EELV was intended to cut launch costs and simplify satellite launch processes. After sitting on the pad since late-2003 and enduring technical issues with both the booster and the payload, the first of the Delta IV launch vehicles to fly from SLC-6 successfully lifted off at 8:33 p.m. PDT on 27 June 2006. According to a post-launch Boeing News press release, the mission was the first for the NRO aboard a Delta IV and the second aboard a Delta rocket. Another Delta IV Medium vehicle flew a mission for the Air Force
Defense Meteorological Satellite Program, orbiting DMSP-17, on 4 November 2006. The Delta IV and the lease on SLC-6 were turned over to
United Launch Alliance (ULA) when ULA was formed as a joint venture of Boeing and
Lockheed Martin Space in December 2006. On 20 January 2011, at 1:10 p.m. PST,
USA-224 (NROL-49) was launched atop a
Delta IV Heavy rocket. The launch was conducted by ULA and was the first flight of a Delta IV Heavy from Vandenberg. On 24 September 2022, ULA launched the last Delta IV Heavy from the pad, concluding their use of SLC-6.
Vulcan Centaur, Delta IV Heavy's successor, will launch from the
Atlas V's old pad of
SLC-3E at Vandenberg.
SpaceX (from 2023) On 24 April 2023, the
United States Space Force announced that it was leasing SLC-6 to
SpaceX for
Falcon 9 and
Falcon Heavy launches and landings. Prior to its leasing, there was interest among other companies for control over the pad thanks to its large size, most notably by
Blue Origin for their
New Glenn orbital launch vehicle. SpaceX intends to use SLC-6 as a secondary pad at Vandenberg to compliment their existing facility at
Space Launch Complex 4 East (SLC-4E). This is similar to their use of
LC-39A and
SLC-40 at Cape Canaveral. As part of modifications to the pad, plans call for the demolition of most existing Shuttle and Delta IV-era infrastructure, replacing them with a traditional
horizontal integration facility and
transporter erector setup with two Falcon
landing pads as seen at SpaceX's other pads. Since the lease, they have started preparing the launch pad for this reconfiguration, with construction slated to commence in late 2025. The first launch may occur in late 2026, but more likely in early 2027 ==Launch history==