LJ-1LJ-1 (Little Joe 1) was one of the unmanned Mercury launches. The goal of the launch was to determine how well the
escape rocket would function under the most severe dynamic loading conditions anticipated during
a Mercury-Atlas launching. A Boiler Plate Capsule was attached to a Little Joe
booster for the test.
On August 21, 1959, evacuation of the
Wallops Island launch 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 the scheduled launchtime, an explosive flash occured.
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 2000 ft, the clamping ring that held
tower to the capsule released and the small
rocket for jettisoning the tower fired.
The accident report for LJ-1, issued September 18, 1959,
blamed the premature firing on 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.