Heat Shield Sample, Gemini VIII

This is a fragment from the heat shield that protected the Gemini 8 spacecraft against the enormous heat of reentry into the atmosphere beginning at a velocity of more than 27,500 kilometers (17,000 miles) per hour. Like those of other early manned spacecraft, Gemini's heat shield derived from ballistic-missile warhead technology. The dish-shaped shield created a shock wave in the atmosphere that held off most of the heat. The rest dissipated by ablation--charring and evaporation of the shield's surface. Ablative heat shields are not reusable.

This fragment was part of the heat shield of Gemini 8, which carried astronauts Neil Armstrong and David Scott into orbit on March 16, 1966. After the mission, Gemini 8's heat shield was cut up for evaluation as part of the military Manned Orbiting Laboratory program. In 1968, manufacturer McDonnell Aircraft, on behalf of NASA, gave the pieces of the heat shield to the Smithsonian.