Unlike the Mercury and Apollo spacecraft, which had rocket-powered "escape towers" to pull the capsule away from the booster in an emergency, the two-man Gemini used ejection seats to allow the astronauts to escape. These seats were probably used in training Gemini astronauts. Ling-Temco-Vought (LTV), which built and operated simulators, delivered them to the Smithsonian for NASA in 1968.