Saturn I and IB (1964–1968) Launch Complex 37 began construction in 1959, being envisioned to be a second site to launch the experimental
heavy-lift Saturn rockets, joining
Launch Complex 34 (LC-34) to the south. Originally, it was planned to be the launch site for an
Earth orbit rendezvous (EOR) strategy to potentially be taken by the Apollo program, where a launch vehicle such as the
Saturn C-3 would launch both the
trans-lunar injection stage and the
Lunar Excursion Module from the two pads, while the crew would lift off from LC-34 and intercept the two payloads in
low Earth orbit. Despite
NASA opting for a
Lunar orbit rendezvous (LOR) approach and using the
Saturn V from
Launch Complex 39 to the north, they nonetheless accepted LC-37 to support the
Saturn I program in 1963. at LC-37B in 1968|left The original layout of the launch complex featured one Mobile Service Structure which could be used to service or mate a rocket on either LC-37A or 37B, but not on both simultaneously. The first launch from LC-37 came on January 29, 1964, launching
Saturn I SA-5 as part of the rocketry development portion of the Apollo program. Over the next two years, a total of six uncrewed Saturn I flights were launched from the complex, mostly carrying
boilerplate Apollo capsules alongside the three launches of the
Pegasus project. In late 1965, both LC-37 and LC-34 were modified to launch the Saturn I's successor, the
Saturn IB. Similarly to its previous configuration, this was in support of Apollo development before the Saturn V's activation at
Kennedy Space Center; however, the original purpose of EOR was also made ready as a backup in case complications render the Saturn V and LOR unfeasible. Only two Saturn IB launches were made from LC-37: the first one was
AS-203 (or informally Apollo 3), which launched on July 5, 1966 and tested engine restart capabilities on the
S-IVB upper stage. The second one was
Apollo 5, lifting off on January 22, 1968 and carrying the first operational test of the
Apollo Lunar Module in space. The complex was officially put into active service with the first launch of the Delta IV on November 20, 2002, carrying
Eutelsat 70A to
geostationary transfer orbit. On December 21, 2004, SLC-37 supported the maiden flight of the
Delta IV Heavy, which aimed at carrying a boilerplate and an assortment of small satellites into orbit. The next year, citing issues that sprang up with competition, Boeing announced that Delta operations at the pad and at SLC-17 would be combined with those of
Atlas V at
Space Launch Complex 41 (SLC-41) as part of a
joint venture with
Lockheed Martin. This handover would be made official with the establishment of
United Launch Alliance (ULA) in December 2006, and SLC-37 supported its first launch under ULA with a Delta IV Heavy flight on November 11, 2007. During the Delta IV era, SLC-37 underwent 35 launches of the family, consisting of 29 Medium launches and 16 Heavy launches. Almost all payloads launched were governmental in nature, with a majority of that subsection being military customers such as the Air Force, the
United States Navy, and the
National Reconnaissance Office. Some notable missions launched from the facility include
GOES-N,
GOES-O, and
GOES-P for
NOAA throughout the late 2000s,
Exploration Flight Test-1 for NASA's
Orion spacecraft in 2014, and the
Parker Solar Probe in 2018. Throughout the late 2010s and early 2020s, ULA began to wind down operations at the complex in preparation for the Delta IV's retirement. Their new launch vehicle to replace the Delta and Atlas families,
Vulcan Centaur, was planning on having its launch site be at SLC-41 and as such ULA opted to let the SLC-37 lease expire. The final Delta IV Medium launch came on August 22, 2019 carrying a
GPS satellite for the Air Force, while the last overall launch of the Delta family came with a Delta IV Heavy launch for the NRO on April 9, 2024.
Starship (from 2025) During the lead up to the Delta IV's retirement, the
United States Space Force (having taken over the Air Force's jurisdiction at Cape Canaveral) and
SpaceX began evaluating SLC-37 as a potential launch site for
Starship. This would complement SpaceX's existing operations at
Starbase and its plans for
Launch Complex 39A at
Kennedy Space Center. As part of the process, the
Federal Aviation Administration was tasked with preparing an
environmental impact statement (EIS). The draft EIS, initially expected in December 2024, was released in June 2025. The final study's release was posted in November 2025, with a
record of decision being formally issued by the
Department of the Air Force on November 20. SpaceX plans to construct two launch pads with integration towers on the eastern portion of SLC-37, designed to support a potential flight cadence of up to 76 launches per year. On June 12, the
mobile service structure and
lightning towers for the Delta IV pad were imploded in a
controlled demolition. The leasing provoked some criticism from residents of neighboring communities such as
Titusville and
Cape Canaveral, with worries being primarily aired about
noise pollution stemming from the high launch cadence at SLC-37 and LC-39A. == Launch statistics ==