Little Joe 1 (LJ-1) was a failed launch of a Little Joe by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedi ...

, a

solid fuel Solid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fuel ...

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entire ...

that was designed for a Max Q abort and

launch escape system A launch escape system (LES) or launch abort system (LAS) is a crew-safety system connected to a space capsule that can be used to quickly separate the capsule from its launch vehicle in case of an emergency requiring the abort of the launch, suc ...

test for the Mercury capsule. The objective was to determine how well the escape rocket would function under the most severe dynamic loading conditions anticipated during a Mercury-Atlas launching. The vehicle was in height, weighed approximately , and was in diameter with a fin span of . The Little Joe booster consisted of four Pollux and four Recruit clustered, solid-fuel rockets, could develop a

thrust Thrust is a reaction force In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can al ...

of , and could lift a maximum

payload Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...

of . The escape system, using a Grand Central 1KS52000 rocket motor, weighed . On 21 August 1959, LJ-1 was being prepared for launch from the

Wallops Flight Facility Wallops Flight Facility (WFF) is a rocket launch site on Wallops Island on the Eastern Shore of Virginia, United States, just east of the Delmarva Peninsula and approximately north-northeast of Norfolk. The facility is operated by the Goddar ...

Wallops Island Wallops Island is a island in Accomack County, Virginia, part of the Virginia Barrier Islands that stretch along the eastern seaboard of the United States of America. It is just south of Chincoteague Island, a popular tourist destination. Wa ...

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the East Coast of the United States, Atlantic Coast and the Appalachian Mountains. The geography an ...

. At 35 minutes before launch, evacuation of the area had been proceeding on schedule and the batteries for the programmer and destruct system in the test booster were being charged. Suddenly, half an hour before launch time, an explosive flash occurred. When the smoke cleared it was evident that only the capsule-and-tower combination had been launched, on a trajectory similar to an off-the-pad abort. The booster and adapter-clamp ring remained intact on the launcher. Near apogee, at about 610 m, the clamping ring that held tower to capsule released and the little pyro-rocket for jettisoning the tower fired. The flight time was 20 seconds. The accident report for LJ-1, issued 18 September 1959, blamed the premature firing of the Grand Central escape rocket on an electrical leak, or what missile engineers call transients or ghost voltages in a relay circuit. The fault was found in a coil designed to protect biological specimens from too rapid an abort.Reference NASA SP-4201 p. 208 According to the 18 September 1959 accident report, the unexpected triggering of the launch escape system was caused by a transient or electrical leak; analysis showed it to be due to the rapid-abort system being wired directly into the destruct arming

busbar In electric power distribution, a busbar (also bus bar) is a metallic strip or bar, typically housed inside switchgear, panel boards, and busway enclosures for local high current power distribution. They are also used to connect high volt ...

. The batteries were shipped from England to the U.S. uncharged and shorted; on charging at the pad, the batteries, when enough charge was reached, actuated the sequencer for the abort system, and sensing insufficient altitude, fired the squibs in the abort motor. Insufficient power in the batteries then failed to initiate the tower jettison motor and capsule parachute recovery charge, and both crashed into the sea.

Notes and References

External links

This New Ocean: A History of Project Mercury—NASA SP-4201
{{Project Mercury Project Mercury 1959 in spaceflight