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 (pronounced "ess two"), 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 (LH2) and
liquid oxygen (LOX) in addition to support fluids, gaseous
helium (GHe), gaseous
hydrogen (GH2) and gaseous
nitrogen (GN2) 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. 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 (AS-502) 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 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.
Summary These two test stands tested and flight-certified S-II stages and J-2 engines until the end of the Apollo program in the early 1970s.
1970s–2000s It was announced in 1971 that the center would be performing tests on the engines for the new
Space Shuttle program (called the
SSME). The A-1 and A-2 test stands, originally designed to accommodate the physically much larger S-II J-2 engines, were modified to accept the smaller SSME, and testing officially began on May 19, 1975, when the first such engine was tested on the A-1 stand. The center continued to test engines for the duration of the shuttle program, on the A-1 and A-2 stands with the final scheduled test occurred on July 29, 2009, on the A-2 stand.
2010s As the shuttle program is phased out, the A-1 and A-2 test stands are seeing new use testing the next generation of rocket engines, including the
J-2X engine designed to power the SLS upper stage, with the first such test occurring on December 18, 2007. Stennis tested
Aerojet Rocketdyne AJ26 rocket engines for
Orbital Sciences Corp. of Dulles, Va., which partnered with NASA to provide commercial cargo flights to the
International Space Station. Orbital's
Antares rocket was powered by a pair of these AJ26 engines. Orbital's maiden flight to the space station launched from NASA's Wallops Flight Facility in Virginia September 18, 2013, powered by two AJ26 engines (E9 and E12) that were tested at Stennis on May 3, 2012 and January 18, 2013.
2020s The A-1 Test Stand was designated the Fred Haise Test Stand in March 2020, in honor of the
Apollo 13 astronaut and
Biloxi, Mississippi, native. == B-1/B-2 Test stand ==