Remembering John Glenn, the Mercury astronaut and former U.S. senator who died today at 95.

On April 9, 1959, NASA introduced its very first astronaut class. This dashing group of young men is known as the Mercury 7. They were all military test pilots before they were chosen for the job, and they had all "the right stuff" to...

Mercury Program astronauts, wearing civilian clothes, sit in Mercury capsules / Virgil 'Gus' Grissom, Scott Carpenter, Walter Schirra, Jr., John Glenn, Jr, L Gordon Cooper, Jr, Donald 'Deke' Slayton, and Alan Shepard on January 01, 1961...

Engineers and technicians working on Project Mercury capsules on January 01, 1960 (Footage by Getty Images)

Mercury Program astronauts training in classroom and conducting survival training in the desert at Stead Air Force Base on July 01, 1960 in Reno, Nevada (Footage by Getty Images)

Spectators looking through binoculars and telescopes, eagerly awaiting Mercury Atlas 6 launch / television camera crews covering the event / banner saying, 'The Voice of America' / sign for ABC Radio News / Mercury rocket is launched...

Helicopters and naval ship assist with recovery of Mercury Freedom 7 capsule on May 05, 1961 (Footage by Getty Images)

Project Mercury, MA-7, MA-8 and MA-9: L Gordon Cooper suits up during Mercury Atlas 7 mission, brief shot in MCC / liftoff and ascent / spectators watching / Wally Schirra during onboard film of Mercury Atlas 8 / Earth view / capsule in...

helicopters recover Mercury Freedom 7 space capsule / Alan Shepard, first American in space, after the recovery on May 05, 1961 (Footage by Getty Images)

Mercury 7 Program astronauts in training classroom / CU John Glenn / L Gordon Cooper pointing on January 01, 1961 (Footage by Getty Images)

Mercury 7 astronauts wearing flight suits and posing for photographs in front of Convair 106-B aircraft / They are, left to right, M Scott Carpenter, L Gordon Cooper Jr, John Glenn Jr, Virgil Grissom, Walter M Schirra Jr, Alan B Shepard...

Project Mercury astronaut John Glenn as seen from onboard camera, Mercury Control Center tracking chart and countdown clock. Astronaut John Glenn in Project Mercury capsule on February 20, 1962 in Space (Footage by Getty Images)

Mercury Program astronauts deplaning from American Airlines airplane, wearing suits and posing for photographs on January 01, 1961 (Footage by Getty Images)

US Air Force airplane on tarmac / Mercury Program astronauts in zero gravity / Gus Grissom at flight controls on January 01, 1961 (Footage by Getty Images)

Project Mercury Redstone 4 rocket on launch pad / Virgil 'Gus' Grissom suited up, climbs into Liberty Bell 7 space capsule / spacecraft is launched / spectators taking pictures on July 21, 1961 in Cape Canaveral, Florida (Footage by...

Banners in Cocoa Beach welcoming John Glenn home, 'Welcome Back John' / cheering people along parade route road, waving American flags / ceremony at Manned Space Center in Houston, Texas, honoring John Glenn / President John Kennedy...

Astronauts Alan Shepard and John Glenn eating breakfast before Project Mercury III mission on July 28, 1961 in Cape Canaveral, Florida (Footage by Getty Images)

Astronaut Alan Shepard in Freedom 7 capsule as he becomes the first American in space on May 05, 1961 in In Space (Footage by Getty Images)

NASA Paresev 1-A on lake bed with project Mercury Astronaut Gus Grissom / testing the feasibility of using a steerable kite-like parawing as a replacement for parachutes used then to safely land spacecraft on Earth / The project was...

Astronaut Alan Shepard wearing spacesuit and preparing for Project Mercury III mission / technician testing spacesuit speaker system on July 28, 1961 in Cape Canaveral, Florida (Footage by Getty Images)

Project Mercury Atlas 6 mission / NASA mission control, countdown clock / Atlas 6 rocket lift-off carrying astronaut John Glenn, who became the first American to orbit the Earth. Project Mercury Atlas 6 lift off on February 20, 1962 in...

Mercury Redstone 3 rocket on launch pad with Freedom 7 capsule / astronaut Alan Shepard makes his way to the launch pad as he becomes the first American in space / NASA TV-1 trucks on May 05, 1961 in Cape Canaveral, Florida (Footage by...

Group of young spectators sitting in convertible car eagerly await launch / teary-eyed middleaged woman awaits launch, closing eyes and praying / lines of people and cars along beach front / man sitting on folding chair atop roof,...