Who were the Mercury 7?

On April 9, 1959, NASA introduced its first astronaut class: the Mercury 7.

The seven members made history, and became the subject of fascination and adoration.

John Glenn, who died Thursday, was the last surviving member of the group.

Alan B. Shepard, Jr. (1923-1998): Alan Shepard was the first American in space. He also walked on the moon. 

On May 5, 1961, Shepard launched into space aboard the Freedom 7 capsule atop a Redstone rocket from Cape Canaveral. The flight lasted 15 1/2 minutes and did not orbit Earth; instead, Shepard flew 116 miles high and returned to Earth. His second flight was as commander of Apollo 14 in 1971, with Edgar Mitchell and Stuart Roosa. On the moon, Shepard and Mitchell collected more than 100 pounds of moon rocks, and Shepard became the first person to hit a golf ball on the moon.

John Glenn, an American hero, dies at 95

Virgil I. "Gus" Grissom (1926-1967): Virgil "Gus" Grissom became the second American in space when he piloted the Liberty Bell 7 spacecraft on the second and final suborbital Mercury test flight on July 21, 1961. His flight lasted 15 minutes and 37 seconds and flew 118 miles high. 

On March 23, 1965, he was command pilot of the first manned Gemini flight on a three-orbit mission.

He was picked to be the command pilot on the first three-man Apollo flight. During a launch pad test, the Apollo spacecraft suffered a flash fire on the pad on January 27, 1967 at Kennedy Space Center. Grissom, Ed White and Roger Chaffee were killed.

John H. Glenn, Jr. (1921-2016): John Glenn became the first American to orbit the Earth on Feb. 20, 1962 aboard Friendship 7 launched from Cape Canaveral. He completed three orbits around the Earth on a 4-hour, 55-minute and 23-second flight. Glenn returned home a hero, having given Americans hope that they could catch up – and surpass – the Soviet Union.

In 1998, Glenn returned to flight on STS-95 Discovery. The nine-day mission launched on Oct. 29, 1998, orbiting Earth 134 times.

Glenn died Thursday.

M. Scott Carpenter (1925-2013): Scott Carpenter followed Glenn into space, launching on the Aurora 7 on May 24, 1962. The mission ran into problems, though, with fuel for maneuvering thrusters running low, forcing NASA to end the flight after two orbits rather than the scheduled three.

He was active in NASA's Manned Spaceflight Center, playing a role in the design of the Apollo Lunar Landing Module. But he never flew in space again.

Walter M. Schirra, Jr., (1923-2007): Water Schirra was the only astronaut to fly in the Mercury, Gemini and Apollo programs.

His first flight was on the Sigma 7 on Oct. 3, 1962, making five revolutions around the Earth. He commanded Gemini 6A in 1965, a flight with Tom Stafford that was the first rendezvous of two manned spacecraft when Gemini 6A and Gemini 7 flew in formation for five hours, as close as one foot from each other.

Schirra also commanded Apollo 7, the first manned Apollo flight. During that 11-day flight in 1968, he and fellow crew members Walt Cunningham and Donn Eisele tested the Apollo systems in Earth orbit and proved it was ready to take astronauts to the moon.

L. Gordon Cooper, Jr. (1927-2004): Gordon Cooper piloted Faith 7 on a 22-orbit mission on May 15-16, 1963, bringing to an end Project Mercury. 

He also served as command pilot of the Gemini 5 mission, which began on August 21, 1965. During that flight, Cooper and pilot Charles Conrad established a new space endurance record by traveling a distance of 3,312,993 miles in an elapsed time of 190 hours and 56 minutes. Cooper also became the first man to make a second orbital flight.

Altogether, he logged 222 hours in space.

Donald K. "Deke" Slayton (1924-1993): Deke Slayton was originally scheduled to pilot the Aurora 7 mission, piloted by Scott Carpenter, but was relieved of this assignment due to a heart condition discovered in August 1959.

It wasn't until 1972 that Slayton was restored to full flight status and then he made his first flight on the Apollo-Soyuz Test Project mission, July 15-24, 1975 in the historic first meeting in space of American astronauts and Soviet cosmonauts.