— One of the United States' most-storied space launch sites has been cleared of its decades-old support towers, making way for modern rockets to use the pad. Space Launch Complex-6 (SLC-6) at Vandenberg Space Force Station is arguably more famous for what did not lift off from there then what did.

A series of demolition charges on Tuesday (June 16), brought down the access tower, mobile service tower and what remained of the assembly building at SLC-6 — pronounced "slick-six" — in southern California. Once the location for the U.S. Air Force's first effort to put humans into space and later, the almost West Coast launch site for the space shuttle, SLC-6 will next be used by SpaceX in support of Falcon 9 and Falcon Heavy missions.

"Space Launch Complex-6 represents six decades of American innovation and our unwavering commitment to securing space superiority," Col. James T. Horne III, commander of Space Launch Delta 30 at Vandenberg, said in a statement. "By modernizing this historic footprint in partnership with our defense industrial base, we are building directly upon the foundation of our pioneers."

The demolition was known to be planned, but was only announced hours after it was completed at 11 a.m. PDT (1800 GMT) on Tuesday. The detonations brought down the access tower first, followed by the mobile service tower and then the large American flag-adorned assembly building. Typical of Vandenberg weather, a marine layer of low clouds and fog added a somber look to the scene.

Have pad, will not launch

SLC-6 was first developed beginning in 1966 to support the Air Force's first effort to send astronauts into Earth orbit to conduct reconnaissance using a vehicle and hardware adapted from NASA's Project Gemini. The site's mobile service tower and concrete apron were built for the Titan IIIM modified missile, but the program was canceled in June 1969 before any launches from SLC-6 could be conducted.

Looking to recoup some of its investment from the MOL infrastructure, the Air Force next chose SLC-6 as its launch site for Department of Defense (DOD, now Department of War) dedicated space shuttle missions. With the intention of moving the orbiter Discovery permanently to California, the Air Force designed SLC-6 differently from NASA's Kennedy Space Center, most notably by stacking the vehicle directly on the pad rather than in a more distant assembly building.

In the end, only the prototype Enterprise was stood up with an external tank and solid rocket boosters on SLC-6 before the Challenger tragedy in 1986 caused the DOD to rethink its reliance on the shuttle. Again the Air Force walked away from the built-up facility, having never launched a single mission.

After a brief effort to revive SLC-6 for use with the Titan IV in the early 1990s, the site finally saw its first operational use with the launch of Lockheed Martin's LMLV-1 in 1995, followed by Athena I and Athena II rockets with payloads for NASA and Space Imaging (later GlobalEye) in 1997 and 1999, respectively.

Boeing (later United Launch Alliance or ULA) then leased the site and modified the shuttle-legacy structures, including the assembly building, mobile service tower and access tower, for a series of 10 Delta IV rocket launches on missions for the National Reconnaissance Office (NRO). The final launch from SLC-6 to date was of a Delta IV Heavy on Sept. 24, 2022.

SpaceX at SLC-6

In 2023, SpaceX signed a lease to use SLC-6 for its Falcon rockets. Tuesday's demolition advanced the company's plans toward modernizing the site.

Since 2013, SpaceX has and continues to launch Falcon 9 rockets from Space Launch Complex-4 (SLC-4) at Vandenberg.

In addition to now having use of SLC-6 itself, SpaceX in 2016 acquired the orbiter transporter system (OTS) originally developed for the West Coast site. The 76-wheel motorized vehicle is now used to transport flown Falcon 9 first stages from the company's Cape Canaveral facilities to its Florida launch pads.

According to a 2025 environmental impact study, SpaceX expects it will take an additional 18 months to complete modifications for SLC-6, including building two landing pads for the reusable Falcon 9 first stage boosters. Falcon Heavy launches could then begin as soon as 2030, pending the needs of the NRO.

"We are not just updating infrastructure," said Horne. "We are leveraging industry capabilities to field a more resilient space enterprise, ensuring the United States is prepared to protect our national interests and meet future challenges for decades to come."