| Moonport: A History of Apollo Launch Facilities and Operations|
Building a Launch Complex
By the late 1950s, the Cape Canaveral skyline already had distinctive features. Towering gantries rose along "ICBM Row." The various missiles had certain similarities in ground environmental needs and operational requirements. In the test phase, each required an assembly and checkout building, transport from assembly area to launch complex, a launch pad, a gantry service tower, a blockhouse for on-site command and control of the launch, and a network of power, fuel, and communication links that would bring it to life. For a long while, the complexes resembled each other. Igloo shaped blockhouses stood 230 meters from the pads and looked like the pillboxes of World War II. They provided protection for the launch crew and the control consoles and instrumentation. In the case of complexes 11, 12, 13, and 14, designed for the Atlas ICBM, the inside walls of the 12-sided domed structures were 3.2 meters thick at the base with 12 meters of sand around them.
ICBM row, December 1967.
Besides the blockhouse or launch control center, the essential features of a fixed-pad complex included a concrete or steel pedestal on which to erect and launch the vehicle, a steel umbilical tower to provide fluid and electrical connections to the vehicle, a flame deflector, and a mobile service structure that moved around the vehicle so ground crews on platforms could service and test various components. Other features of the complex included an operations support building, storage facilities for kerosene and liquid oxygen, a tunnel for instrumentation and control cables, roads, camera sites, utilities services, and security.
Three factors largely determined the choice of sites for the launch complexes: explosive hazards, the dangers of overflight, and lines of sight. In 1959 the launch planners assumed that the first five or ten missiles in a new program would have a high rate of failure on the pad or shortly after launch. Approximately 5% of the Cape's previous developmental launches had exploded a few seconds after takeoff, most of them in an area 10 degrees to either side of the intended azimuth (direction) of launch. Experience thus showed the wisdom of locating a pad in an area where there were no permanent facilities immediately downrange. Likewise, the frequency of accidents during test programs made backup pads desirable. The explosive hazard further influenced the placement of facilities within the launch site to minimize damage to "long-lead-time" equipment. Planners also had to maintain a clear line of sight from the launch vehicle to the launch control center, and to electronic and optical instrumentation sites.11
To meet the constantly expanding needs of the many missile groups, the Corps of Engineers eventually built 21 missile assembly buildings patterned after Marine Corps hangars at El Toro, California. Shop, office, and assembly area met the requirements of the early missiles; inside, a maze of power and instrumentation circuits ran through covered trenches. Criteria prepared by the Facilities Division of the Joint Long Range Proving Ground standardized the basic framework of the last 18 of these assembly buildings and developed overhead cranes that were interchangeable in all structures.12 As missiles grew more complicated over the years, the assembly buildings began to reflect the characteristics of the individual vehicles they would service.13