wears the Apollo Block I pressure suit The Gemini spacesuit was chosen by NASA for the initial
Apollo Block I Earth orbital concept demonstrator phase of Apollo. Since EVA was impractical due to the hatch design of the Block I spacecraft, and with a design competition underway between
ILC Dover,
Hamilton Standard (later Hamilton Sunstrand), and David Clark for a new Block II lunar EVA suit, NASA decided to use the G3C as the base for the Apollo Block I suit, designated
A1C. This version added new electrical and environmental disconnects, and a protective shell over the helmet visor, which reverted to the more economical Plexiglas. Since Apollo would use a
launch escape system in place of Gemini's
ejection seats, a yellow-colored U-shaped inflatable "Mae West"
personal flotation device replaced the pilot parachute and its harness. Only two Block I flights were initially planned until December 1966, when the second one, to be flown by
Wally Schirra,
Donn F. Eisele, and
Walter Cunningham, was canceled as unnecessary duplication. Astronauts Grissom, White, and
Roger B. Chaffee were wearing A1C suits on January 27, 1967 in a preliminary countdown demonstration test for the planned February 21
Apollo 1 launch, when they were killed in a cabin fire, leading to NASA cancelling crewed Block I flights and use of the A1C suit. Since the fire had burned through the suits, NASA added a fireproofing requirement to the new suit, which replaced the outer layer with
beta cloth. The Block II suit was designated
A7L and manufactured by ILC Dover. The new suit was first used on Apollo 1's replacement flight,
Apollo 7 flown by Schirra, Eisele and Cunningham in October 1968. ==Post-Apollo applications==