History Early years The first development on this site was in 1890 when a few wealthy graduates of Harvard University purchased the 18,000 acres (73 km2) property for one dollar per acre. Very nearly on the site of 39A they constructed a three-story mahogany clubhouse with twenty rooms for members and guests. The club featured a large dining room, wine cellar, trophy room and plenty of storage for arms and ammunition. Atop the lodge, there was a spectacular view of both ocean and wildlife that flocked to the surrounding marsh. During the 1920s, P. E. Studebaker, son of the automobile magnate, built a small casino at De Soto Beach eight miles (13 km) north of the Canaveral lighthouse to lure buyers to the site where plans were being developed for an elaborate resort city, complete with water, sewer, sidewalks, street lights, and landscaping. Also, the Playa Linda Development Corporation sought buyers to their 'proposed' development of 8,000 lots of 0.25 acres (1,000 m2) advertised as the "greatest beach development north of Miami." Prior to the construction of the complex, State Road A1A ran east of the complex. Along this rural ocean road was United States Coast Guard Station Chester Shoals built in 1885. In 1948, the Navy transferred the former Banana River Naval Air Station located south of the Cape Canaveral, to the Air Force for use in testing captured German V-2 rockets. The site's location on the East Florida coast was ideal for this purpose in that launches would be over the ocean, away from populated areas. This site became the Joint Long Range Proving Ground in 1949, and was renamed Patrick Air Force Base in 1950. The Air Force annexed part of Cape Canaveral to the North in 1951, forming the Air Force Missile Test Center, the future Cape Canaveral Air Force Station (CCAFS). Missile and rocketry testing and development would take place here through the 1950s. NASA arrives NASA was founded in 1958, and the early NASA missions, including the Mercury and Gemini programs, were launched from pads on CCAFS. In 1961, President Kennedy announced the goal of landing a man on the Moon by the end of the decade. The announcement of the lunar program led to an expansion of operations from the Cape to the adjacent Merritt Island. NASA began acquisition of land in 1962, taking title to 131 square miles (340 km2) by outright purchase and negotiating with the state of Florida for an additional 87 square miles (230 km2). In July 1962, the site was named the Launch Operations Center. At the time, the highest numbered launch pad on CCAFS was Launch Complex 37; when the lunar launch complex was designed, it was designated as Launch Complex 39. Initial design The initial design of the launch complex contained five pads that were evenly spaced 8,700 feet (2,700 m) apart to avoid damage in the event of a pad explosion. Three were scheduled for construction (A-C, to the southeast) and two reserved for future use (D and E, west and north). The numbering of the pads at the time was from north to south, with the northernmost being LC-39A, and the southern being LC-39C. LC-39A was never built, and LC-39C became LC-39A in 1963. With today's numbering, LC-39C would be north of LC-39B. LC-39D would have been due west of LC-39C. LC-39E would have been due north of the mid-distance between LC-39C and LC-39D, with LC-39E forming the top of a triangle, and equidistant from LC-39C and LC-39D. The crawler way was built with the additional pads in mind. This is the reason the crawler way turns as it heads to Pad B; continuing straight from that turn would have led to the additional pads. There were plans for an unbuilt Nuclear Assembly Building (NAB). The shape of launch pad A, approximately 2,297 square feet (0.7 square kilometers), was roughly octagonal. The elevated launch pad, which rises 39.4 feet (12 meters) above ground level, lay in a north-south direction. This orientation requires the crawlerway to make a near right-angle turn before approaching the ramp sloping 5 degrees upward to the top of the pad. Bisecting the pad is the flame trench, level with the surrounding area at its base, measuring 59 feet (18 meters) wide and 449.5 feet (137 meters) long. On each side of the flame trench, a cellular structure supports a thick surface, called a hardstand. The mobile launcher and the Apollo-Saturn vehicle was placed on top of this reinforced slab for launch. The two-story pad terminal connection room and the single-story environmental control systems room are within the western side of the pad. The former houses the electronic equipment that connects communication and digital data link transmission lines from the launch control center to the mobile launcher when it was on the pad. A service road would border the south side of the crawlerway from the VAB to pad A. Underground ducts for communication and instrumentation lines to link the control and assembly areas with the launch pads would parallel the north side of the crawlerway; power line ducts and a pipeline for drinking water would go along the south side. Where any of the ducts or pipes had to pass beneath the crawlerway, the access tunnels had to be capable of withstanding the load conditions. The completed crawlerway would be level with the terrain, 7.5 feet (2.3 meters) above sea level. Weather Considerations Calculations showed that, should wind velocities reach 200 kilometers per hour, the Apollo service structure, standing by itself on its four support legs in the parked position, with side struts and hold-down arms for each leg, could exert about 6,300 metric tons of force. To withstand these anticipated forces, the parking site had to have a heavily reinforced base. Early launches The pads were first used for launches of the Saturn V rocket for the Project Apollo moon missions, and later for Saturn 1B rockets for the Skylab and Apollo-Soyuz programs. The original structure of the pads was remodeled for the needs of the Space Shuttle, starting with LC-39A after the last Saturn V launch, which carried Skylab in 1973, and in 1977 for LC-39B after the Apollo-Soyuz Test Project in 1975. During the Apollo era these were just launchpads - the umbilical/service towers were attached to the launch platform�the only modification made was the so-called "milkstool" which allowed the Saturn IB rocket (for all manned Skylab missions, the unlaunched Skylab Rescue, and ASTP) to use the Saturn V launch tower. For the Shuttle, the pad had a fixed tower (left over from the Apollo-Saturn era) and a rotating service platform, used to protect the Shuttle Orbiter and to install vertically handled payloads into the payload bay. The first use of LC-39 came in 1967 with the first Saturn V launch, carrying the unmanned Apollo 4 spacecraft. The second unmanned launch, Apollo 6, also used LC-39A. With the exception of Apollo 10, which used LC-39B (due to the "all-up" testing resulting in a 2-month turnaround period), all manned Apollo-Saturn V launches, commencing with Apollo 8, used LC39A. After the launch of Skylab in 1973, using the Saturn INT-21 rocket (a two-stage variation of the Saturn V rocket originally intended for the Apollo Applications Program), LC-39A was reconfigured for the Space Shuttle and was used for the first Shuttle launch (STS-1), using the Columbia in 1981. After Apollo 10, LC-39B was kept as a backup launch facility in the case of the destruction of LC-39A, but saw service for all three Skylab missions, the ASTP flight, as well as un-launched Skylab Rescue flight. After ASTP, LC-39B underwent the same reconfiguration as LC-39A, but due to necessary modifications (mainly to allow the facility to service a modified Centaur-G upper stage), along with budgetary restraints, it was not ready until 1986, and the first Shuttle launch to use it was the ill-fated STS-51-L flight � the Challenger disaster. 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 SRB's flames. The subsequent mishap investigation found that the damage was the result of carbonation of epoxy and corrosion of steel anchors which held the refractory bricks in the trench in place. These had been exacerbated by the fact that hydrochloric acid is an exhaust by-product of the solid rocket boosters. Space shuttle usage Space Shuttle-era Modifications The launch pads are taken out of service every three to five years for maintenance and modifications. This �Mod Period� lasts six to nine months, during which several contractors are tasked with specific modifications. Some tasks completed in 2003 on Pad A were adding a new 5,000-square-foot operations building and computer-automating the Payload Ground Handling Mechanism (PGHM). The Pad A operations building is a mix of office and shop space, providing space for NASA, United Space Alliance and subcontractor personnel previously scattered around the complex. They include pad operations managers, quality and safety personnel, system engineers, planners and schedulers and shops for the cryogenic, hypergolic, electrical and environmental control systems. The building also houses personnel for payload, external tank/solid rocket boosters and Space Shuttle main engine operations at the pads. Consolidation of the personnel into one site has reduced maintenance requirements as well as increased efficiency and morale. The PGHM is used in the Payload Changeout Room on the Rotating Service Structure to remove payloads from a transportation canister and install them into the orbiter. Essentially, NASA's largest forklift, the PGHM is now controlled by a single operator, compared to the previous method of two or three working hand controls. It has greater tolerance for accuracy. Other work has included upgrading Apollo-era electrical power systems, adding new safety tie-off points and performing corrosion control. Corrosion of metal structures are endemic to the waterside environment. The metal pad structures are stripped and repainted on a recurring basis. Sand blasting and repainting are best done during a Mod Period because they stop all other work and create a foreign object debris situation. Integration of launch vehicle stack The thrust to allow the Space Shuttle to achieve orbit was provided by a combination of the Solid Rocket Boosters (SRBs) and the Space Shuttle Main Engines (SSMEs). The SRBs used solid propellant, hence their name. The SSMEs used a combination of liquid hydrogen and liquid oxygen (LOX) from the External Tank (ET), as the orbiter did not have internal fuel tanks for the SSMEs (as they would be have had to be as large as the External Tank). Months before launch, the three main components of the "stack" were brought together in the Vehicle Assembly Building (VAB). The components were placed on a Mobile Launcher Platform (MLP). The SRBs arrived in segments via rail car from their manufacturing facility in Utah, the External Tank arrived from its manufacturing facility in Louisiana by barge, and the orbiter waited in the Orbiter Processing Facility (OPF). The SRBs were first stacked, and then the External Tank was mounted between them. Then, using a massive crane, the orbiter was lowered and connected to the External Tank. Transportation to the pad To lift, hold and move what would be the largest, tallest and heaviest known portable structures on Earth, the crawler-transporter was designed. Adapted from self-propelled, strip-mining shovels, the massive machines weighed 5.5 million pounds unloaded. This alone required a special roadway to support loads never envisioned for a public road -- in excess of 127,867 pounds (58,000 kilograms) per square meter. The design would comprise dual trackways, separated by a median strip, and would consist of more than three feet (1 meter) of selected sub-base material, topped by 3 feet (1 meter) of graded crushed aggregate, with a blacktop sealer over all.When the stack integration was completed, it was moved by the Crawler-Transporter the 3�4 miles (5-6 kilometers) to the pad over eight hours. At the pad, the MLP was lowered onto several pedestals, and the Crawler-Transporter moved off the pad to a staging area a safe distance away. Payload to be installed at the launch pad was independently transported in a payload transportation canister then installed vertically at the Payload Changeout Room. Otherwise, payloads would have already been pre-installed at the Orbiter Processing Facility and transported within the orbiter's cargo bay. Launch towers Each pad contained a two-piece access tower system, the Fixed Service Structure (FSS) and the Rotating Service Structure (RSS). The FSS permitted access to the Shuttle via a retractable arm and a "beanie cap" to capture vented LOX from the External Tank. The RSS contained the Payload Changeout Room, which offered "clean" access to the orbiter's payload bay, protection from the elements, and protection in winds up to 60 knots (110 km/h). Also at each pad were large cryogenic tanks that stored the liquid hydrogen and liquid oxygen (LOX) for the SSMEs. The highly explosive nature of these chemicals required numerous safety measures at the Launch Complex. NASA calculated the minimum safe distance for a fully fueled Space Shuttle stack was three miles (5 km) for personnel, and 8,700 feet (2,700 m) between pads. Before tanking operations began and during launch, non-essential personnel were excluded from the danger area. The Launch Control Center and Vehicle Assembly Building (VAB) were almost exactly three miles (5 km) away. Swing arms Swing arms were retractable mechanical systems that extended from the launch tower to the Space Shuttle. They provided access to the vehicle for people, wiring and plumbing while the vehicle was on the launch pad. They retracted by swinging away before launch. People (technicians, engineers, and astronauts) used the Orbiter Access Arm to access the crew module. At the end of the arm, the white room provided an environmentally controlled and protected area for astronauts and their equipment to enter the orbiter. The Gaseous Oxygen Vent Arm positioned a hood, often called the "Beanie Cap," over the top of the External Tank (ET) nose cone during fueling. Heated gaseous nitrogen was used there to remove the extremely cold gaseous oxygen that normally vented out of the External Tank. This prevented the formation of ice that could fall and damage the shuttle. The Hydrogen Vent Line Access Arm mated the External Tank (ET) Ground Umbilical Carrier Plate (GUCP) to the launch pad hydrogen vent line. The GUCP provided support for plumbing and cables, called umbilicals, that transferred fluids, gases, and electrical signals between two pieces of equipment. While the ET was being fueled, hazardous gas was vented from an internal hydrogen tank through the GUCP, out a vent line to a flare stack where it was burned off at a safe distance. Sensors at the GUCP measured gas level. The GUPC was redesigned after leaks created scrubs of STS-127 and were also detected during attempts to launch STS-119 and STS-133. The GUCP released from the ET at launch and fell away with a curtain of water sprayed across it for protection from flames. Hypergolic Storage The orbiter�s Orbital Maneuvering System and Reaction Control System burn monomethyl hydrazine as a fuel and nitrogen tetroxide as an oxidizer. These hypergolic fluids are stored in well-separated areas on the southwest and southeast corners of the pads, respectively. Transfer lines convey the fluids through the FSS to the Hypergolic Umbilical System located on the RSS, with its three pairs of umbilicals attaching to the orbiter. Pad Terminal Connection Room Connections between the Launch Control Center, mobile launcher platform and shuttle stack are made in the Pad Terminal Connection Room (PTCR). The facility was a 2-story series of rooms beneath the launch pad, constructed of reinforced concrete located on the west side of the flame trench and was protected by up to 20 feet (6.1 m) of fill dirt. Sound suppression water system A Sound Suppression System was installed on the pads and MLP to protect the orbiter and its payloads from being damaged by acoustical energy reflected from the MLP during liftoff. Water stored in a 290-foot-high, 300,000-gallon tank on the northeast side of the pad is released just prior to main engine ignition and flows by gravity to special MLP outlets, including six 12-foot-high quench nozzles, or �rainbirds.� Nine seconds after liftoff, peak flow rate is 900,000 gallons per minute. A water spray system provides a cushion of water which is directed into the flame hole directly beneath each booster. A series of water bags stretched across the flame holes, providing a water mass to dampen the reflected pressure pulse, supplements this effort. Used together, this water barrier blocks the path of the reflected pressure wave from the boosters, greatly decreasing its intensity. The system reduces acoustical levels within the orbiter payload bay to about 142 decibels, below the design requirement of 145 decibels. Launch Pad/MLP Interfaces The Space Shuttle is brought to the pad atop the Mobile Launcher Platform (MLP) and Crawler-Transporter. The MLP is parked on pedestals permanently located at the pad and is the platform from which the Shuttle is launched. Several MLP systems interface with pad systems. These include the Sound Suppression System and the propellant transfer lines for the external tank. Helium and nitrogen, as well as ground electrical power and connections for vehicle data and communications, also are established through the tail service masts of the MLP. The Space Shuttle Main Engine Hydrogen Burnoff System, located inside the tail service masts, eliminates free hydrogen present prior to main engine ignition. Hydrogen vapors are exhausted into the main engine nozzles during the start sequence; if ignited when the main engines ignite, a small explosion could ensue, which might damage the engine bells. Emergency pad evacuation In an emergency, the launch complex used a slidewire escape basket system for quick evacuation. Assisted by members of the closeout team, the crew would leave the orbiter and ride an emergency basket to the ground at speeds reaching up to 55 miles per hour (89 km/h). From there, the crew took shelter in a bunker. A modified M113 Armored Personnel Carrier could carry injured astronauts away from the complex to safety. Future use With the retirement of the Shuttle in 2011, the future of LC-39 is undetermined following cancellation of Project Constellation in 2010. From Wikipedia and NASA