Santa Susana Field Laboratory. The company sought a location for a manufacturing plant nearby the Simi Hills testing site. In 1954, North American Aviation purchased 56 acres of land within the current Warner Center area then deeded the property to the Air Force. The Air Force, in turn, designated the site Air Force Plant No. 56 and contracted with Rocketdyne to build and operate the facility. NAA completed construction of the main manufacturing building and designated Rocketdyne as a new company division in November 1955. Rocketdyne's success resulted in the addition of buildings within a growing footprint. At its peak, the Rocketdyne Canoga facility comprised some 27 different buildings over 119 acres of land, including over one million square feet of manufacturing area plus 516,000 square feet of office space. The Canoga plant grew into areas both east and southeast of the original location. In 1960, Rocketdyne opened a headquarters building at the southeast corner of Victory Boulevard and Canoga Avenue. A pedestrian tunnel underneath Victory Boulevard east of Canoga Avenue provided access between buildings to the South (including the Headquarters) and those located to the North of the street. (The tunnel was removed in 1973.) The Canoga plant shrank over time via piecemeal property sales and building demolitions into the 2000s. With the completion of the Apollo program in 1969, Rocketdyne ended the leases of several facilities and returned the headquarter offices to the Canoga Main building. In 1973, Rocketdyne repurchased the Air Force Plant No. 56 property thereby ending the government designation. The Space Shuttle program ended in 2011 and further reductions followed. Pratt and Whitney retained ownership of the Canoga property when Rocketdyne was sold to Aerojet in 2013; the remaining property measured roughly 47 acres with building and structures comprising a total of 770,000 square feet. Rocketdyne played a key role in the United States space program and the development of propulsion systems. Ten years after being established, the Canoga plant produced the vast majority of America's United States liquid rocket engines (except those of the Titan rocket, them being built by Aerojet). Through the end of the twentieth century, Rocketdyne products powered all major engines for the Saturn program and every space program in the United States. Six specific periods of liquid rocket engine development and manufacturing programs took place at the Canoga plant: Atlas (1954-late 1960s), Thor (1961-1975), Jupiter (1955-1962), Saturn (1961-1975); Apollo (1961-1972);