WASHINGTON — The U.S. Space Force is allocating three launch complexes at Cape Canaveral, including one used for several NASA Mercury missions six decades ago, to four small launch vehicle startups as the service tries to keep up with growing launch demand.

Space Launch Delta 45, which operates the Eastern Range, announced late March 7 it assigned three sites at Cape Canaveral Space Force Station to four startups, only one of which has attempted an orbital launch so far.

Space Launch Complex 15, which was used for Titan 1 and 2 launches in the 1960s, will go to ABL Space Systems, which made its first, unsuccessful orbital launch attempt in January from Kodiak Island, Alaska. The company said in a tweet that it will temporarily conduct launches of its RS1 rocket from SLC-46, a pad that has been used by several vehicles, including Astra’s Rocket 3.3, on a short-term basis while it renovates SLC-15.

The Space Force assigned SLC-14 to Stoke Space, a company that is developing a fully reusable launch vehicle. The launch complex was used for Atlas launches from 1957 through 1966, and was the site where John Glenn launched on Mercury-Atlas 6 in February 1962, becoming the first American to orbit the Earth. Three subsequent Mercury missions also launched from the pad.

“Needless to say, this is incredibly humbling,” Andy Lapsa, chief executive of Stoke Space, said. “We will work tirelessly to make his legacy, our country, and our world proud.”

SLC-13, the Space Force announced, would go to two small launch vehicle developers, Phantom Space and Vaya Space (formerly known as Rocket Crafters.) Both companies are working on small launch vehicles.

The assignment of SLC-13 raised questions because that facility, used for Atlas launches from the late 1950s through the late 1970s, is now operated by SpaceX. That company built two landing pads there, called Landing Zones 1 and 2, for landings of Falcon boosters. That included a Falcon 9 launch of OneWeb satellites March 9.

A spokesperson for Space Launch Delta 45 referred questions March 10 about SpaceX’s continued use of the launch complex to the company. SpaceX did not respond to questions March 8 about its future use of SLC-13; the company rarely responds to media inquiries.

None of the four companies have disclosed details about what infrastructure they plan to build at the launch sites and when they expect to start using them. ABL Space Systems, for example, has minimized the ground equipment it needs for its RS1 rocket, designing it to fit into shipping containers for transportability.

Space Launch Delta 45 said it made the assignments through an initiative called the Launch Pad Allocation Strategy, which it said is designed for “maximizing opportunities” for commercial launch providers at the Cape and for increasing the launch capacity of the Eastern Range.

The growing pace of activity at the Eastern Range, which includes Cape Canaveral Space Force Station and neighboring NASA Kennedy Space Center, has put a strain on infrastructure, including available launch pads. “Today, every single pad we have on the Cape is occupied by somebody or multiple somebodies,” said Col. James Horne, deputy director of operations for the Space Force’s Space Systems Command, during a panel at the SpaceCom conference in Orlando Feb. 22. “There’s massive congestion, tons of construction going on.”

Asked during the panel if the Space Force was looking at opening up historic pads, like SLC-14, for new users, Horne said it was, but he did not elaborate on that effort.

A Space Force spokesperson said the four companies selected for the pads were “already accepted programs” on the Eastern Range, having been reviewed for safety considerations as well as financial and technological capabilities. The service also issued a request for information last September to identify additional potential users, but that effort did not find any eligible companies.

Space Launch Delta 45 said it may consider future rounds of the Launch Pad Allocation Strategy that could include support for larger launch vehicles “after further operational analysis.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...