Estes Little Joe I

About the real Little Joe

The Little Joe was a pioneer solid-fuel test vehicle designed by NASA and built by North American Aviation. It served as a simple, low-cost booster to qualify the Project Mercury capsule for human spaceflight.

Purpose and Design

• Main Mission: To test the capsule's launch escape system under critical conditions (especially at maximum dynamic pressure, or "max q"), as well as aerodynamics, parachute deployment, and recovery operations. It also carried biological payloads, including the monkeys Sam and Miss Sam.

• Propulsion: The unguided rocket used a cluster of solid-propellant motors (four main, four supplemental) that fired in sequence, producing up to 230,000 pounds of thrust.

• Visual Structure: Fired almost vertically, it relied entirely on four large aerodynamic fins for stabilization.

• Name Origin: The nickname came from the craps dice throw of a "double deuce." Early cross-section drawings showed four holes for the rocket motors, resembling a four on the dice.

Technical Specifications

• Height: 15.20 m (49.80 ft)

• Diameter: 2.03 m (6.66 ft)

• Gross Mass: 12,700 kg (27,900 lb)

• Apogee: 89 km (55 mi)

• Status: Retired 1961