Kennedy Space Center Launch Complex 39A

In early 1960s, the highest numbered launch pad at CCAFS was Launch Complex 37. When the lunar launch complex was designed, it was designated as Launch Complex 39. It was designed to handle launches of the Saturn V rocket, the largest, most powerful rocket then designed, which would propel Apollo spacecraft to the Moon. Initial plans envisioned four pads (five were considered) evenly spaced 8,700 feet (2,700 m) apart to avoid damage in the event of an explosion on a pad. Three were scheduled for construction (A, B, and C, to the southeast), and two (D and E, west and north) would have been built at a later date. The numbering of the pads at the time was from north to south, with the northernmost being 39A, and the southernmost being 39C. Pad 39A was never built, and 39C became 39A in 1963. With today's numbering, 39C would have been north of 39B, and 39D would have been due west of 39C. Pad 39E would have been due north of the midpoint between 39C and 39D, with 39E forming the top of a triangle, and equidistant from 39C and 39D. The Crawlerway was built with the additional pads in mind. This is the reason the Crawlerway turns as it heads to Pad B; continuing straight from that turn would have led to the additional pads.[4]

The first launch from Launch Complex 39A came in 1967 with the first Saturn V launch, which carried the uncrewed Apollo 4 spacecraft. The second uncrewed launch, Apollo 6, also used Pad 39A. With the exception of Apollo 10, which used Pad 39B (due to the "all-up" testing resulting in a 2-month turnaround period), all crewed Apollo-Saturn V launches, commencing with Apollo 8, used Pad 39A.

The original structure of the launch pad was remodeled for the needs of the Space Shuttle after the last Saturn V launch, with shuttle launches beginning with STS-1 in 1981, flown by the Space Shuttle Columbia.[5] The first usage of the pad for the Space Shuttle came in 1979, when Enterprise was used to check the facilities prior to the first operational launch.

During the launch of Discovery on STS-124 on May 31, 2008, the pad at LC-39A suffered extensive damage, in particular to the concrete trench used to deflect the SRBs' flames.[6] The subsequent investigation found that the damage was the result of carbonation of epoxy and corrosion of steel anchors that held the refractory bricks in the trench in place. The damage had been exacerbated by the fact that hydrochloric acid is an exhaust by-product of the solid rocket boosters.[7]

Just as for the first 24 shuttle flights, LC-39A supported the final shuttle flights, starting with STS-117 in June 2007 and ending with the retirement of the Shuttle fleet in July 2011. Prior to the SpaceX lease agreement, the pad remained as it was when Atlantis launched on the final shuttle mission on July 8, 2011, complete with a mobile launcher platform.

KSC Director Bob Cabana announces the signing of the pad 39A lease agreement on April 14, 2014. SpaceX COO Gwynne Shotwell stands nearby.

Talks for use of the pad were underway between NASA and Space Florida—the State of Florida's economic development agency—as early as 2011, but no deal materialized by 2012, and NASA then pursued other options for removing the pad from the federal government inventory.[8]

By early 2013, NASA publicly announced that it would allow commercial launch providers to lease LC-39A,[9] and followed that, in May 2013, with a formal solicitation for proposals for commercial use of the pad.[10] There were two competing bids for the commercial use of the launch complex.[11] SpaceX submitted a bid for exclusive use of the launch complex, while Jeff Bezos' Blue Origin submitted a bid for shared non-exclusive use of the complex, so that the launchpad would handle multiple vehicles, and costs could be shared over the long-term. One potential shared user in the Blue Origin plan was United Launch Alliance.[12] Prior to the end of the bid period, and prior to any public announcement by NASA of the results of the process, Blue Origin filed a protest with the U.S. General Accounting Office (GAO) "over what it says is a plan by NASA to award an exclusive commercial lease to SpaceX for use of mothballed space shuttle launch pad 39A."[13] NASA had planned to complete the bid award and have the pad transferred by October 1, 2013, but the protest "will delay any decision until the GAO reaches a decision, expected by mid-December."[13] On December 12, 2013, the GAO denied the protest and sided with NASA, which argued that the solicitation contained no preference on the use of the facility as multi-use or single-use. "The [solicitation] document merely asks bidders to explain their reasons for selecting one approach instead of the other and how they would manage the facility."[14]

On December 13, 2013, NASA announced that it had selected SpaceX as the new commercial tenant.[15] On April 14, 2014, SpaceX signed a lease agreement[16] that gave it a 20-year exclusive lease on LC-39A.[11] SpaceX planned to launch their launch vehicles from the pad and build a new hangar nearby.[11][16][17] Elon Musk, CEO of SpaceX, stated that he wanted to shift most of SpaceX's NASA launches to LC-39A, including commercial cargo and crew missions to the International Space Station.[15][18]

In 2015, SpaceX built the Horizontal Integration Facility (HIF) just outside the perimeter of the existing launch pad in order to house both the Falcon 9 and the Falcon Heavy rockets, and their associated hardware and payloads, during preparation for flight.[19] Both types of launch vehicles will be transported from the HIF to the launch pad aboard a Transporter Erector (TE) which will ride on rails up the former crawlerway path.[8][19] Also in 2015, the launch mount for the Falcon Heavy was constructed on Pad 39A over the existing infrastructure.[20][21] The work on both the HIF building and the pad was substantially complete by late 2015.[22] A rollout test of the new Transporter Erector was conducted in November 2015.[23]

In February 2016, SpaceX indicated that they had "completed and activated Launch Complex 39A",[24] but still had more work yet to do to support crewed flights. SpaceX originally planned to be ready to accomplish the first launch at pad 39A—of a Falcon Heavy—as early as 2015,[25] as they had had architects and engineers working on the new design and modifications since 2013.[26][20] By late 2014, a preliminary date for a wet dress rehearsal of the Falcon Heavy was set for no earlier than July 1, 2015.[8] Due to a failure in a June 2015 Falcon 9 launch, SpaceX had to delay launching the Falcon Heavy in order to focus on the Falcon 9's failure investigation and its return to flight.[27] In early 2016, considering the busy Falcon 9 launch manifest, it became unclear if the Falcon Heavy would be the first vehicle to launch from Pad 39A, or if one or more Falcon 9 missions would precede a Falcon Heavy launch.[24] In the following months, the Falcon Heavy launch was delayed multiple times and eventually pushed back to February 2018.[28]

In 2019, SpaceX began substantial modification to LC 39A in order to begin work on phase 1 of the construction to prepare the facility to launch prototypes of the large 9 m (30 ft)-diameter methalox reusable rocket—Starship—from a launch stand, which will fly from 39A on suborbital test flight trajectories with six or fewer Raptor engines. A second phase of the construction is planned for 2020 to build a much more capable launch mount capable of launching the entire Starship launch vehicle,[29] powered by 43 Raptor engines and producing a total of 72 MN (16,000,000 lbf) liftoff thrust when departing 39A.[30]

The first SpaceX launch from pad 39A was SpaceX CRS-10 on February 19, 2017, using a Falcon 9 launch vehicle; it was the company's 10th cargo resupply mission to the International Space Station,[31] and the first uncrewed launch from 39A since Skylab.

While Cape Canaveral's Space Launch Complex 40 (SLC-40) was undergoing reconstruction after the loss of the AMOS-6 satellite on September 1, 2016, all SpaceX's east coast launches were from Pad 39A until SLC-40 became operational again in December 2017. These included the May 1, 2017, launch of NROL-76, the first SpaceX mission for the National Reconnaissance Office, with a classified payload.[32]

On February 6, 2018, Pad 39A hosted the successful liftoff of the Falcon Heavy on its maiden launch, carrying Elon Musk's Tesla Roadster car to space;[33] and the first flight of the human-rated spacecraft Crew Dragon (Dragon 2) took place there on March 2, 2019.

The second Falcon Heavy flight, carrying the Arabsat-6A communications satellite for Arabsat of Saudi Arabia, successfully launched on April 11, 2019. The satellite is to provide K_u band and K_a band communication services for the Middle East and northern Africa, as well as for South Africa. The launch was notable as it marked the first time that SpaceX was able to successfully soft-land all three of the reusable booster stages, which will be refurbished for future launches.[34]

The SpaceX Demo-2 test flight launched with astronauts Bob Behnken and Doug Hurley from Launch Complex 39A on 30 May 2020, and docked to pressurised mating adapter PMA-2 on the Harmony module of the ISS on 31 May 2020.[35][36][37]