# Cape Canaveral Space Launch Complex 37

Space Launch Complex 37 (SLC-37), previously Launch Complex 37 (LC-37), is a launch complex on Cape Canaveral Space Force Station, Florida. Originally built to support the Apollo program, the complex consists of two launch pads: LC-37A and SLC-37B. 37A has never been used, while 37B hosted Saturn I and Saturn IB launches in the 1960s as well as Delta IV and Delta IV Heavy launches throughout the 2000s, 2010s, and early 2020s.
Currently, the pad is not leased to anyone. However, SpaceX has a limited right of entry to explore using SLC-37 as a future launch site for Starship.

## History
### 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.
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, it's 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 facility was deactivated in 1972, following the conclusion of the Apollo program. Proposals were drawn of resuming Saturn IB launches from LC-37 and LC-34 as part of the Apollo Applications Program, but NASA instead opted to modify Launch Complex 39B for that role. LC-37 would sit dormant for the next 30 years.

### Delta IV and Delta IV Heavy (2002-2024)

In 1998, the United States Air Force and Boeing came into an agreement to use LC-37 for launching the Delta IV as part of the Evolved Expendable Launch Vehicle program. Having acquired the Delta family following their merger with McDonnell Douglas the previous year, Boeing aimed for the Delta IV to be a complement and not a replacement to the other active members of the time, the Delta II and Delta III. As such (and taking the difference in lift capabilities into account), a new launch site similar in size to LC-37 was needed rather than continuing to use Space Launch Complex 17 (SLC-17). Facility modifications were made to LC-37B in 2001, constructing a 330 ft (100 m) tall Mobile Service Tower fitted to service all planned Delta IV configurations. The complex as rechristened as SLC-37 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 launch 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.

### Future proposals

Following the retirement of the Delta IV, the Federal Aviation Administration announced that they would be creating a draft environmental impact statement (EIS) for the potential use of SpaceX's Starship at SLC-37, despite the pad not being officially leased out to anyone by the United States Space Force. The draft was originally set to be released by December 2024 but subsequently was delayed to Spring 2025, with the final study being due by September of that year.
In March 2025, SpaceX announced that they received a limited right of entry for SLC-37. While this was not an official leasing announcement, they clarified in a statement that this issuing was in regards to the exploration and due diligence of the pad in support of the Starship EIS.

## Launch statistics
### Rocket configuration

* Saturn I
* Saturn IB
* Delta IV
* Delta IV Heavy

### Saturn

All flights operated by NASA.
| Date | Vehicle | Mission | Payload | Remarks |
| Jan. 29, 1964 | Saturn I | SA-5 | none | First live S-IV second stage |
| May 28, 1964 | Saturn I | AS-101 | BP-13 boilerplate CSM | First boilerplate CSM |
| Sept. 18, 1964 | Saturn I | AS-102 | BP-15 boilerplate CSM | |
| Feb. 16, 1965 | Saturn I | AS-103 | Pegasus 1 and BP-16 boilerplate CSM | Pegasus satellites studied micrometeoroid impacts |
| May 25, 1965 | Saturn I | AS-104 | Pegasus 2 and BP-26 boilerplate CSM | Pegasus satellites studied micrometeoroid impacts |
| July 30, 1965 | Saturn I | AS-105 | Pegasus 3 and BP-9A boilerplate CSM | Pegasus satellites studied micrometeoroid impacts |
| July 5, 1966 | Saturn IB | AS-203 | none | Test of S-IVB second stage; informally called Apollo 3 |
| Jan. 22, 1968 | Saturn IB | Apollo 5 | LM-1 | First uncrewed orbital test of the lunar module |

### Delta

* view
* talk
All launches from 2002 to 2006 were operated by Boeing. All launches from 2007 to 2024 were operated by United Launch Alliance.
| Date (UTC) | Vehicle | Payload | Launch outcome |
| 20 November 2002 | Delta IV Medium | Eutelsat W5 | Success |
| 11 March 2003 | Delta IV Medium | USA-167 (DSCS-3 A3) | Success |
| 29 August 2003 | Delta IV Medium | USA-170 (DSCS-3 B6) | Success |
| 21 December 2004 | Delta IV Heavy | DemoSat, Sparkie / 3CS-1 and Ralphie / 3CS-2 | Partial failure |
| 24 May 2006 | Delta IV Medium | GOES-N (GOES-13) | Success |
| 11 November 2007 | Delta IV Heavy | DSP-23 Defense Support Program | Success |
| 18 January 2009 | Delta IV Heavy | Orion 6 / Mentor 4 (USA-202 / NROL-26) | Success |
| 27 June 2009 | Delta IV Medium | GOES-O (GOES-14) | Success |
| 6 December 2009 | Delta IV Medium | USA-211 (WGS-3) | Success |
| 4 March 2010 | Delta IV Medium | GOES-P (GOES-15) | Success |
| 28 May 2010 | Delta IV Medium | USA-213 (GPS IIF SV-1) | Success |
| 21 November 2010 | Delta IV Heavy | Orion 7 / Mentor 5 (USA-223 / NROL-32) | Success |
| 11 March 2011 | Delta IV Medium | USA-227 (NROL-27) | Success |
| 16 July 2011 | Delta IV Medium | USA-232 (GPS IIF-2) | Success |
| 20 January 2012 | Delta IV Medium | USA-233 (WGS-4) | Success |
| 29 June 2012 | Delta IV Heavy | Orion 8 / Mentor 6 (USA-237 / NROL-15) | Success |
| 4 October 2012 | Delta IV Medium | USA-239 (GPS IIF-3) | Success |
| 25 May 2013 | Delta IV Medium | USA-243 (WGS-5) | Success |
| 8 August 2013 | Delta IV Medium | USA-244 (WGS-6) | Success |
| 21 February 2014 | Delta IV Medium | USA-248 (GPS IIF-5) | Success |
| 17 May 2014 | Delta IV Medium | USA-251 (GPS IIF-6) | Success |
| 28 July 2014 | Delta IV Medium | USA 253-255 (AFSPC-4 (GSSAP #1/#2/ANGELS)) | Success |
| 5 December 2014 | Delta IV Heavy | Orion Exploration Flight Test-1 (EFT-1) | Success |
| 25 March 2015 | Delta IV Medium | USA-260 (GPS IIF-9) | Success |
| 24 July 2015 | Delta IV Medium | USA-263 (WGS-7) | Success |
| 11 June 2016 | Delta IV Heavy | Orion 9 / Mentor 7 (USA-268 / NROL-37) | Success |
| 19 August 2016 | Delta IV Medium | USA-270/271 (AFSPC-6 (GSSAP #3/#4)) | Success |
| 7 December 2016 | Delta IV Medium | USA-272 (WGS-8) | Success |
| 19 March 2017 | Delta IV Medium | USA-275 (WGS-9) | Success |
| 12 August 2018 | Delta IV Heavy | Parker Solar Probe | Success |
| 16 March 2019 | Delta IV Medium | USA-291 (WGS-10) | Success |
| 22 August 2019 | Delta IV Medium | USA-293 (GPS III-2) | Success |
| 11 December 2020 | Delta IV Heavy | Orion 10 / Mentor 8 (USA-268 / NROL-44) | Success |
| 22 June 2023 | Delta IV Heavy | Orion 11 / Mentor 9 (NROL-68) | Success |
| 9 April 2024 | Delta IV Heavy | Orion 12 / Mentor 10 (NROL-70) | Success |

## Photos

* Map of Launch Complex 37 of the 1960s, with original Mobile Service Structure
* The launch of AS-103 with the Pegasus 1 satellite atop a Saturn I, from LC-37B in 1965
* The launch of GOES-N atop a Delta IV, from SLC-37B in 2006
* SLC-37B in 2010, with the Mobile Service Tower