S88-55873 (1961) --- Astronaut Virgil I. (Gus) Grissom, pilot of the Mercury-Redstone 4 (MR-4) spaceflight. (NOTE: Astronaut "Gus" Grissom, one of the original seven astronauts, died Jan. 27, 1967, at NASA?s John F. Kennedy Space Center (KSC), Cape Canaveral Florida, in the Apollo 1 spacecraft fire.) Photo credit: NASA

S62-01358 (1962) --- Project Mercury astronaut M. Scott Carpenter, prime pilot of the Mercury-Atlas 7 (MA-7) spaceflight, goes through a water egress test. He is in the Mercury pressure suit, without the helmet, and is wearing a life vest. Photo credit: NASA

S62-08895 (1962) --- Astronaut Walter M. Schirra Jr., pilot of the Mercury-Atlas 8 (MA-8) Earth-orbital spaceflight, goes through a suiting-up exercise in Hangar "S" at Cape Canaveral several weeks prior to his scheduled Oct. 3, 1962 flight. Photo credit: NASA

S62-00249 (1962) --- View of astronaut John H. Glenn Jr. being fitted with gloves for his spacesuit during preflight training activities at Cape Canaveral, Florida. Glenn is assisted by suit technician Joe Schmitt. Photo credit: NASA

S88-55875 (19 July 1961) --- Donning a spacesuit for the Mercury-Redstone 4 (MR-4) mission, astronaut Virgil I. (Gus) Grissom chats with spaceflight equipment specialist Joe W. Schmitt in the personal equipment room of Hangar S at Cape Canaveral, Florida. Shortly after this photograph was taken, the launch was postponed two days due to unfavorable weather conditions in the area. Photo credit: NASA

S64-36908 (1962) --- Portrait view of astronaut M. Scott Carpenter, wearing Mercury pressure suit, posing for pictures during astronaut training at the Cape Canaveral, Florida. Photo credit: NASA

S64-36910 (February 1962) --- Astronaut John H. Glenn Jr., wearing a Mercury pressure suit, was the pilot of the Mercury-Atlas 6 (MA-6) mission. Glenn made America's first manned Earth-orbiting spaceflight on Feb. 20, 1962. This photograph was taken at Cape Canaveral, Florida, during MA-6 preflight training activities. Photo credit: NASA

S62-00246 (5 Feb. 1962) --- Astronaut John H. Glenn Jr. is assisted by Joe W. Schmitt as he suits up in practice for the preparation of Mercury-Atlas 6 (MA-6) mission. Photo credit: NASA

S64-14843 (1962) --- Astronaut John H. Glenn Jr., pilot of the Mercury-Atlas 6 Earth-orbital space mission, is suited up at Cape Canaveral, Florida, during MA-6 preflight activities. Assisting Glenn is suit technician Al Rochford. Photo credit: NASA

S62-01355 (1962) --- Project Mercury astronauts M. Scott Carpenter, prime pilot of the Mercury-Atlas 7 (MA-7) spaceflight, prepares to go through a water egress test. Astronaut Walter M. Schirra (back to camera), the backup MA-7 pilot is also present. Carpenter and Schirra are in the Mercury pressure suit, without the helmet. Behind them is an inflated life raft. Photo credit: NASA

S61-03510 (1961) --- Project Mercury astronaut M. Scott Carpenter smiles, in his pressure suit, prior to participating in a simulated mission run at Cape Canaveral, Florida. Astronaut Carpenter has been selected as the prime pilot on the United States second attempt to put a man into orbit around Earth. Photo credit: NASA

KENNEDY SPACE CENTER, FLA. -- SUIT CHECK - Project Mercury pressure suit specialist Joe. W. Schidt adjusts a respirometer attached to the helmet of astronaut Virgil I. Grissom during a dress rehearsal for the National Aeronautics and Space Administration's second manned suborbital flight, dubbed Liberty Bell 7, planned for the week of July 16. Respirometer enables ground medical personnel to monitor the pilot's breathing rate during the countdown and flight. Hose attached to the left side of the pilot's suit brings breathing oxygen into the suit. Expelled oxygen is then vented out a port on the side of the helmet and passed through an air conditioning system beneath the astronaut's couch where it is purified before being recycled into the suit. Gauge on left arm indicates pressure within the suit. Canon plug on the right thigh brings medical information out of the suit for telemetering to ground stations. Suit is not inflated during the mission unless there is a failure in cabin pressure, in which event the 'V' shaped cable around the neck ring is adjusted prior to flight to prevent helmet from rising should it be necessary to pressurize the suit

S88-31382 (5 May 1961) --- Astronaut Alan B. Shepard receives assistance in removing his spacesuit while on the U.S. Champlain after the recovery of his Mercury capsule. Photo credit: NASA or National Aeronautics and Space Administration