Stennis Space Center
The John C. Stennis Space Center is a NASA rocket testing facility in Hancock County, Mississippi, United States, on the banks of the Pearl River at the Mississippi–Louisiana border., it is NASA's largest rocket engine test facility. There are over 50 local, state, national, international, private, and public companies and agencies using SSC for their rocket testing facilities.
History
The initial requirements for NASA's proposed rocket testing facility required the site to be located between the rockets' manufacturing facility at Michoud Assembly Facility in eastern New Orleans, Louisiana, and the launch facility at the Kennedy Space Center in Florida. Also, the site required barge access as the rocket stages to be tested for Apollo were too large for overland transport. Additionally, the Apollo motors were too loud to be tested at Marshall Space Flight Center's existing test stands near Huntsville, Alabama. A more isolated site was needed.After an exhaustive site selection process that included reviews of other coastal locations including Eglin Air Force Base in Florida plus islands in both the Caribbean and the Pacific, NASA announced formation of the Mississippi Test Facility on Oct. 25, 1961, for testing engines for the Apollo Program. A high-terrace area bordering the East Pearl River in Hancock County, Miss., was selected for its location. NASA entrusted the U.S. Army Corps of Engineers with the difficult task to procure each land parcel either by directly purchasing the land or through acquisition of a perpetual easement.
The selected area was thinly populated and met all other requirements; however before construction began, five small communities, plus the northern portion of a sixth, and a combined population of 700 families had to be completely relocated off the facility. The effort acquired more than 3,200 parcels of privately owned land – 786 residences, 16 churches, 19 stores, three schools and a wide assortment of commercial buildings, including nightclubs and community centers. Remnants of the communities, including city streets and a one-room school house, still exist within the facility.
The site was selected on October 25, 1961, on the Mississippi Test Facility or Pearl River Site. On December 18, 1961, NASA officially designated the facility as NASA Mississippi Test Operations. The test area is surrounded by a 125,000 acre acoustical buffer zone. The facility's large concrete and metal rocket propulsion test stands were originally used to test-fire the first and second stages of the Saturn V rockets. The facility was renamed again to Mississippi Test Facility on July 1, 1965, became a part of the Marshall Space Flight Center.
Starting in 1971, all Space Shuttle Main Engines were flight-certified at Stennis. On June 14, 1974, the site was renamed National Space Technology Laboratories, a name that continued until May 20, 1988, when it was renamed for Mississippi senator and space program supporter John C. Stennis.
With the end of the Apollo and Shuttle programs, use of the base decreased, with economic impact to the surrounding communities. Over the years, other government organizations and commercial entities have moved to and left from the facility, in the balance providing a major economic benefit to the communities.
Rocket propulsion test complex
The Rocket Propulsion Test Complex is a rocket testing complex which was built in 1965 as a component of the John C. Stennis Space Center. The Rocket Propulsion Test Complex played an important role in the development of the Saturn V rocket. The A-1, A-2 and B-1/B-2 test stands were declared a National Historic Landmark in 1985.The NASA Engineering & Science Directorate at SSC operates and maintains SSC's rocket test stands.
A-1/A-2 Test stand
The smaller two of the original three test stands at Stennis Space Center, the A-1 and A-2 stands were built to test and flight-certify the second stage of the Saturn V, the S-II, the launch vehicle for the Apollo program. The two stands are similar steel and concrete structures are roughly tall, and capable of withstanding thrust loads of more than 1 million pounds and temperature of up to. Each test stand can provide Liquid Hydrogen and liquid oxygen in addition to support fluids, gaseous helium, gaseous hydrogen and gaseous nitrogen as purge or pressurizing gasses.1960s
Construction began in 1963 and was finished in 1966. The A Test Complex also includes a Test Control Center, observation bunkers, and various technical and support systems.On 23 April 1966 workmen at the A-2 test stand successfully captive-fired for 15 seconds the S-II-T, Structural and Dynamic Test Vehicle for the Saturn V second stage, in an all-systems test. This was the first test of a flight-weight S-II stage. The stage, largest and most powerful liquid oxygen-liquid hydrogen stage known, developed one million pounds of thrust from its five Rocketdyne J-2 engines. This test also marked the first operational use of the A-2 stand.
The first full-duration firing of the S-II flight stage occurred 20 May 1966 when S-II-T test-fired on the A-2 test stand for 354.5 seconds. LOX cutoff sensors initiated cutoff automatically. The firing passed all major test objectives with the exception of the propellant utilization system. This was the fourth static firing of the S-II-T. The stage developed one million pounds of thrust from its five hydrogen-oxygen-powered J-2 engines.
S-II-T rupture
A static test version of the Saturn V second stage S-II-T ruptured during pressure tests at SSC on 28 May 1966, and five North American Aviation technicians monitoring the test received minor injuries. The accident occurred when the hydrogen fuel tank failed under pressure. S-II-T, which had five hydrogen-oxygen J-2 engines capable of generating one million pounds of thrust, had been tested May 25 in ground firing but stopped firing after 195 seconds when a hydrogen link leak caused automatic cutoff. At time of the explosion, technicians were trying to determine cause for the hydrogen leak. No hydrogen was in the tank when the explosion occurred. Under the direction of MSFC, a Board of Inquiry headed by Dr. Kurt H. Debus, Director of Kennedy Space Center, convened on the night of May 28. Immediate investigation revealed that the second shift crew, not knowing that the liquid hydrogen pressure sensors and switches had been disconnected, had attempted to pressurize the tank. Believing that a liquid hydrogen vent valve was leaking, the technicians closed the facility by blocking valves. This had caused the vehicle tank to become over-pressurized and burst. On 30 May 1966 the board released its findings after two days of inquiry. The fuel tank of the S-II stage had been pressurized beyond design limits. There was a need for tighter controls over MTF test procedure. Following the destruction of S-II-T, NASA extended the S-II battleship program until July 1967.S-II-1, the first flight S-II stage scheduled for static firing at MTF, left Seal Beach on July 31, 1966.
The first flight model of the Saturn V vehicle's second stage arrived August 13, 1966 at MTF completing its 4,000-mile voyage from Seal Beach. Workmen immediately moved the stage into the S-II stage service and checkout building for inspection and preparation for static firing.
On December 1, 1966, North American Aviation conducted a successful 384-second captive firing of five J-2 engines, the first flight hydrogen-fueled engines, developing a total one million pounds of thrust. During the test, number 2 and 4 engine SLAM arms did not drop, resulting in the successful gimballing of engines 1 and 3 only. The test included the recording of about 800 measurements of the stage's performance, including propellant tank temperatures, engine temperatures, propellant flow rates, and vibrations.
On December 30, 1966, MSFC technicians at the MTF test stand conducted a static firing of the first flight version of the Saturn V second stage, S-II-1. This second test firing, like an earlier firing, lasted more than six minutes.
1967
On January 11, 1967, initial post-static checkout of the S-II-1 stage ended at MTF. On January 27, 1967, the S-II-2 stage left Seal Beach, California, to pass through the Panama Canal and on to MTF. After its journey lasting 16 days, the S-II would arrive at MTF for two static tests. The S-II-2 stage arrived on dock at MTF on February 11, 1967. The S-II-2 stage, part of the second Saturn V vehicle scheduled for launch from KSC late in 1967, was scheduled for testing at MTF late in March 1967. On February 17, 1967, the first full-duration test of a cluster of uprated J-2 engines, S-II battleship test No. 041, lasted 360 seconds. On February 25, 1967, workmen completed construction of the S-II A-1 test stand, and the Corps of Engineers accepted beneficial occupancy with exceptions. On March 17, 1967, technicians fired the S-II battleship stage for a mainstage duration of 29 seconds. On March 31, failure of a prevalve to close caused program officials to scrub the first attempt to static fire the S-II-2 stage.Battleship testing of the S-II battleship test stage equipped with five uprated J-2 engines ended in late March 1967 with a full-duration test of approximately 360 seconds mainstage operation.