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Little Joe 1A



Little Joe 1A (LJ-1A) was the third in a series of suborbital flights designed to test various components of the Mercury flight systems. The primary objectives of the Little Joe booster missions were to: (1) study capsule dynamics at progressively higher altitudes; (2) test the capsule escape system at maximum dynamic pressure; (3) qualify the parachute system; and, (4) verify the search and retrieval methods.

LJ-1A was launched as a test for a planned abort under high aerodynamic load conditions. Objectives were the same as the earlier Little Joe 1 flight. Specific goals of the LJ-1A flight were to: (1) carry out a planned abort of the spacecraft from the booster at the maximum dynamic pressure anticipated during Mercury-Atlas exit flight; (2) obtain added reliability data on the Mercury drogue and main parachute operation; (3) study spacecraft impact behavior; (4) gain further operational experience in recovery of a floating spacecraft utilizing a surface vessel; (5) obtain further experience and confidence in the operation of the booster command thrust termination system; and, (6) recover the escape motor and tower.

After lift-off, the pressure sensing system was to supply a signal when the intended abort dynamic pressure was reached (approximately 30 s after launch). An electrical impuse was then sent to the explosive bolts to separate the spacecraft from the launch vehicle. Up to this point, the operation went as planned. However, the impulse was also supposed to start the igniter in the escape motor. The igniter activated, but pressure failed to build up on the motor until 10 s had elapsed, resulting in a pressure that was only one-tenth of the maximum. As a result, the abort maneuver, the prime objective of the flight, was done at a dynamic pressure that was too low. All other events from the launch through and recovery occurred without incident, but because of the failure of the prime objective, a repeat of the test was planned (and carried out as Little Joe 1B).

The capsule attained an altiude of roughly 9 statute miles and a downrange distance of about 11 statute miles. The total flight time was 8 minutes 11 seconds.

Alternate Names

  • LJ-1A
  • LittleJoe1A
  • Mercury Little Joe 1A

Facts in Brief

Launch Date: 1959-11-04
Launch Vehicle: Little Joe
Launch Site: Wallops Island, United States

Funding Agency

  • National Aeronautics and Space Administration (United States)


  • Engineering

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. Edwin V. Bell, II



NameRoleOriginal AffiliationE-mail

Other Sources of LJ-1A Information/Data

LJ-1A information (NASA KSC)

On-line version of Project Mercury: A Chronology (NASA History Office)

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