Big Joe (Project Mercury) on:
[Wikipedia]
[Google]
[Amazon]
Big Joe 1 (
The Mercury capsule flew a ballistic flight to the altitude of . The capsule was recovered and studied for the effect of re-entry heat and other flight stresses from its 13-minute flight. Since the data from Big Joe 1 satisfied NASA requirements, a second launch, Big Joe 2 (Atlas-20D), which had been scheduled for the fall of 1959, was canceled and the launch vehicle was transferred to the Atlas-Able program.
While the Mercury team was satisfied with the flight, Convair Division engineers were not. The Atlas had failed to stage its booster section and overall vehicle performance was rather marginal. They listed the flight in official records as a failure. The staging problem was traced to a probable failure of the electrical circuit that provided power to the Conax separation valves, so additional instrumentation would be fitted to them on subsequent flights. Convair's morale was soon raised however by the successful launch of Atlas-12D from Vandenberg Air Force Base on the West Coast followed by the vehicle being declared officially "operational".
The Mercury spacecraft used in the Big Joe 1 mission is displayed at the
This New Ocean: A History of Project Mercury – NASA SP-4201
Project Mercury preliminary flight test results of the Big Joe, Mercury R and D capsule (PDF) October 1959
Big Joe 1 Launch Video
{{Project Mercury Project Mercury 1959 in spaceflight Spacecraft launched by Atlas rockets Test spaceflights
Atlas
An atlas is a collection of maps; it is typically a bundle of world map, maps of Earth or of a continent or region of Earth. Advances in astronomy have also resulted in atlases of the celestial sphere or of other planets.
Atlases have traditio ...
-10D) launched an uncrewed boilerplate Mercury capsule from Cape Canaveral
Cape Canaveral () is a cape (geography), cape in Brevard County, Florida, in the United States, near the center of the state's Atlantic Ocean, Atlantic coast. Officially Cape Kennedy from 1963 to 1973, it lies east of Merritt Island, separated ...
, Florida on 9 September 1959. The purposes of the Big Joe 1 were to test the Mercury spacecraft
Project Mercury was the first human spaceflight program of the United States, running from 1958 through 1963. An early highlight of the Space Race, its goal was to put a man into Earth orbital spaceflight, orbit and return him safely, ideally ...
ablative heat shield
In engineering, a heat shield is a component designed to protect an object or a human operator from being burnt or overheated by dissipating, reflecting, and/or absorbing heat. The term is most often used in reference to exhaust heat management a ...
, afterbody heating, reentry dynamics attitude control and recovery capability. It was also the first launch of a spacecraft in Project Mercury.
Two flight readiness firings (FRF) were performed on Big Joe 1. The first, on 1 September 1959, ended immediately after T-0 because the ignition stage delay timer commanded shutdown of the rocket engines when neither sustainer nor main engine ignition followed normal vernier ignition. There was no booster or stand damage. The second FRF was successfully completed on 3 September 1959, with normal ignition, transition to main stage and shutdown by the engine timer after approximately 19 seconds of running time.
The prelaunch countdown went relatively smoothly, with one delay caused by the Atlas's LOX fill and drain valve failing to close. At 08:19 GMT on 9 September, Big Joe lifted from LC-14 atop Atlas-10D. All went well until the two-minute mark when telemetry readouts indicated that the booster section had failed to jettison. The dead weight from the booster engines resulted in below normal velocity, and consequently the guidance system did not generate the planned SECO (''Second Engine Cut-Off'') signal at T+270 seconds because the required altitude and velocity had not been achieved. SECO was instead caused by LOX depletion at T+293 seconds. The Range Safety manual fuel cutoff command was received by the booster, but had no effect because the late SECO had resulted in depletion of helium control gas needed to close the propellant valves. All valves remained open, causing residual engine thrust and bumping of the Mercury capsule following separation. In addition, the guidance system did not generate the separation signal for the capsule due to insufficient altitude and velocity, so ground crews had to repeatedly fire the RCS (Reaction Control System
A reaction control system (RCS) is a spacecraft system that uses Thrusters (spacecraft), thrusters to provide Spacecraft attitude control, attitude control and translation (physics), translation. Alternatively, reaction wheels can be used for at ...
) thrusters to tear the capsule free and in doing so exhausted the propellant supply. Navy recovery crews hurried to locate the capsule following splashdown and after a few hours, did so. The boilerplate Mercury, having landed some short of the target point, was found to have survived the mission in good condition and verified the ablative heat shield. Plans for a beryllium heat shield in the event the ablative one did not work were scrapped.
The Mercury capsule flew a ballistic flight to the altitude of . The capsule was recovered and studied for the effect of re-entry heat and other flight stresses from its 13-minute flight. Since the data from Big Joe 1 satisfied NASA requirements, a second launch, Big Joe 2 (Atlas-20D), which had been scheduled for the fall of 1959, was canceled and the launch vehicle was transferred to the Atlas-Able program.
While the Mercury team was satisfied with the flight, Convair Division engineers were not. The Atlas had failed to stage its booster section and overall vehicle performance was rather marginal. They listed the flight in official records as a failure. The staging problem was traced to a probable failure of the electrical circuit that provided power to the Conax separation valves, so additional instrumentation would be fitted to them on subsequent flights. Convair's morale was soon raised however by the successful launch of Atlas-12D from Vandenberg Air Force Base on the West Coast followed by the vehicle being declared officially "operational".
The Mercury spacecraft used in the Big Joe 1 mission is displayed at the National Air and Space Museum
The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration.
Established in 1946 as the National Air Museum, ...
's Steven F. Udvar-Hazy Center
The Steven F. Udvar-Hazy Center, also called the Udvar-Hazy Center, is the Smithsonian National Air and Space Museum (NASM)'s annex at Dulles International Airport in the Chantilly area of Fairfax County, Virginia. It holds numerous exhibits, ...
in Chantilly, Virginia
Chantilly is a census-designated place (CDP) in western Fairfax County, Virginia, United States. The population was 24,301 as of the 2020 census. Chantilly is named after an early-19th-century mansion and farm, which in turn took the name of an ...
.
See also
* Little Joe *Splashdown
Splashdown is the method of landing a spacecraft or launch vehicle in a body of water, usually by parachute. This has been the primary recovery method of American capsules including NASA’s Mercury, Gemini, Apollo and Orion along with th ...
References
This New Ocean: A History of Project Mercury – NASA SP-4201
Project Mercury preliminary flight test results of the Big Joe, Mercury R and D capsule (PDF) October 1959
External links
Big Joe 1 Launch Video
{{Project Mercury Project Mercury 1959 in spaceflight Spacecraft launched by Atlas rockets Test spaceflights