Launch Complex 20 was constructed by the
United States Air Force in the late 1950s for the
Titan I missile program, alongside
LC-19,
LC-16, and
LC-15 to the south. The pad saw use in this initial configuration in 1960 and 1961, being the site of 16 Titan I launches within that period. LC-20 would later see a brief period of inactivity with the Titan I's replacement by the
LGM-25C Titan II, of which only LC-15 and 16 were used for missile tests. LC-20 and the adjacent LC-19 were modified in 1963 as part of experimentation with the
Titan family to allow for orbital launches.
NASA utilized LC-19 to launch the
Titan II GLV as part of
Project Gemini, while LC-20 was worked by the Air For the Titan III program, being used to launch the
Titan IIIA and its
Transtage third stage. In 1964 and 1965, the launch site was used four times by the Titan IIIA, with three of them being successful. To date, these launches are the only ones out of LC-20 to reach
low Earth orbit. Following being mothballed for two decades, LC-20 saw life with further modifications in the late 1980s for the Starbird launch vehicles associated with the shuttle Starlab mission. From 1990 to 1994, the facility saw five launches, all of them being sounding rockets. LC-20 was deactivated in 1996. In 1999, the site was re-activated to support new launch facilities under the direction of
Space Florida for commercial launches. The re-activation included upgrades to Launch Pad A and the construction of a new building along the perimeter road, northeast of the blockhouse. In February 2019, Space Florida leased the site to
Firefly Aerospace so that they could launch their
Alpha and
Beta (since renamed to Eclipse) launch vehicles from the
Space Coast's
Eastern Range on prograde launch azimuths, being renamed SLC-20 to follow similar rebrandings of pads such as
SLC-40 and
SLC-41. To support upcoming operations at Cape Canaveral, Firefly plans to develop both manufacturing facilities at a nearby Space Florida business park as well as the launch site. This compliments a similar lease arrangement made with the military for
SLC-2W at
Vandenberg Space Force Base as a launch site used for
polar orbital trajectories. As SLC-2W had a much more active history of being used as a launch pad (being the
Western Range site of the
Delta II), Firefly opted to prioritize work on there over SLC-20, seeing the maiden flight of the Alpha in September 2021. In 2024 Firefly indicated they were maintaining their lease at SLC-20 while prioritizing
Wallops Pad 0A at the
Mid-Atlantic Regional Spaceport as their first East Coast launch site, primarily due to their partnership with
Northrop Grumman in the development of the
Antares 330 and Eclipse, also planned to be launched from LP-0A. ==Launch statistics==