SLC-4E is leased as a launch site for the Falcon 9 rocket, which first flew from Vandenberg on 29 September 2013, following a 24-month refurbishment program which had started in early 2011.

[3][4] SpaceX began a five-year lease of Launch Complex 4 West in February 2015 in order to use that area as a landing pad to bring back VTVL return-to-launch-site (RTLS) first-stage boosters of the reusable Falcon 9 launch vehicle.

[5] During 1971 the complex was reactivated and refurbished for use by the Martin Marietta Titan III launch vehicles.

[8] SLC-4E hosted one of the most dramatic launch accidents in US history when a Titan 34D-9 carrying a KH-9 photoreconnaissance satellite exploded a few hundred feet above the pad on 18 April 1986.

The enormous blast showered the launch complex with debris and toxic propellant (hydrazine and dinitrogen tetroxide), resulting in extensive damage.

16 months after the accident, the pad was back in commission when it hosted a successful launch of a KH-11 satellite.

[4] By late 2012, SpaceX anticipated that the initial launch from the Vandenberg pad would be in 2013, with the larger variant Falcon 9 v1.1.

[13] As the pad was nearing completion in February 2013, the first launch was scheduled for summer 2013,[14] but was delayed until September 2013.

[32][33] This novel use of SLC-4W had initially surfaced in July 2014 when NASASpaceFlight.com published that SpaceX was considering leasing SLC-4W for use as a RTLS vertical-landing facility for reusable first-stage boosters.

[20][37] In July 2018, SpaceX filed an FCC permit to communicate with a Falcon 9 first stage post-landing at SLC-4W, hinting at a potential RTLS landing, for the SAOCOM 1A mission.