The launch of the MA-6, Friendship 7, on February 20, 1962. Boosted by the Mercury-Atlas vehicle, a modified Atlas Intercontinental Ballistic Missile (ICBM), Friendship 7 was the first U.S. marned orbital flight and carried Astronaut John H. Glenn into orbit. Astronaut Glenn became the first American to orbit the Earth.

S62-00380 (20 Feb. 1962) --- Close-up view of the Mercury Atlas 6 (MA-6) Friendship 7 capsule on top of its booster rocket with catwalk still attached. Photo credit: NASA

S62-00303 (20 Feb. 1962) --- A camera onboard the "Friendship 7" Mercury spacecraft photographs astronaut John H. Glenn Jr. during the Mercury-Atlas 6 spaceflight. Photo credit: NASA

S62-00302 (20 Feb. 1962) --- A camera onboard the "Friendship 7" Mercury spacecraft photographs astronaut John H. Glenn Jr. during his Mercury-Atlas 6 spaceflight. Photo credit: NASA

Astronaut John Glenn in the Friendship 7 capsule during the first manned orbital flight, the MA-6 mission. Boosted by the Mercury-Atlas vehicle, a modified Atlas (intercontinental ballistic missile), the MA-6 mission lasted for 5 hours and orbited the Earth three times.

Astronaut John H. Glenn, one of the original seven astronauts for Mercury Project selected by NASA on April 27, 1959. The MA-6 mission, boosted by the Mercury-Atlas vehicle, was the first manned orbital launch by the United States, and carried Astronaut Glenn aboard the Friendship 7 spacecraft to orbit the Earth.

S62-00490 (20 Feb. 1962) --- View of Mercury Atlas 6 (MA-6) Friendship 7 capsule on top of its booster rocket with astronaut John H. Glenn Jr. just visible in the open hatch. Photo credit: NASA

S62-00941 (20 Feb. 1962) --- The Mercury-Atlas 6 (MA-6) "Friendship 7" spacecraft is retrieved from the Atlantic Ocean following astronaut John H. Glenn Jr.'s three-orbit space mission. In this view, the capsule is still in the water, with retrieval cable connected to it. Photo credit: NASA

S64-14861 (1962) --- Department of Defense (DOD) recovery personnel and spacecraft technicians from NASA and McDonnell Aircraft Corp., inspect astronaut John Glenn's Mercury spacecraft, Friendship 7, following its return to Cape Canaveral after recovery in the Atlantic Ocean. Photo credit: NASA

Astronaut John H. Glenn sits in a car in front of the east side of the Mercury Mission Control building. Glenn was the pilot for the Mercury-Atlas 6 mission aboard Friendship 7, which launched Feb. 20, 1962.

Astronaut John Glenn enters the Mercury spacecraft, Friendship 7, prior to the launch of MA-6 on February 20, 1961 and became the first American who orbited the Earth. The MA-6 mission was the first manned orbital flight boosted by the Mercury-Atlas vehicle, a modified Atlas ICBM (Intercontinental Ballistic Missile), lasted for five hours, and orbited the Earth three times.

Astronaut John Glenn enters the Mercury spacecraft, Friendship 7, prior to the launch of MA-6 on February 20, 1961 and became the first American who orbited the Earth. The MA-6 mission was the first manned orbital flight boosted by the Mercury-Atlas vehicle, a modified Atlas ICBM (Intercontinental Ballistic Missile), lasted for five hours, and orbited the Earth three times.

S62-00304 (20 Feb. 1962) --- Astronaut John H. Glenn Jr. is pictured aboard the Mercury-Atlas (MA-6) Friendship 7 capsule during the U.S.'s initial orbital flight. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Mercury astronaut John Glenn poses for a photo in front of the Project Mercury monument at Launch Complex-14 LC-14 at Cape Canaveral Air Force Station in Florida. During events at the Cape and NASA's Kennedy Space Center, Glenn is marking the 50th anniversary of being the first American astronaut to orbit the Earth inside the Friendship 7 capsule on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts, John Glenn, left, and Scott Carpenter, talk to Mercury Project workers and other guests in the Astronaut Encounter Theater at the Kennedy Space Center Visitor Complex in Florida. The pair participated in 50th anniversary events at the launch site of Glenn's first orbital flight aboard NASA's Friendship 7 capsule, which launched Feb. 20, 1962, aboard an Atlas rocket. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronaut John Glenn poses for a photo in front of the Project Mercury monument at Launch Complex-14 LC-14 at Cape Canaveral Air Force Station in Florida. During events at the Cape and NASA's Kennedy Space Center, Glenn is marking the 50th anniversary of being the first American astronaut to orbit the Earth inside the Friendship 7 capsule on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts, John Glenn, left, and Scott Carpenter, talk to Mercury Project workers and other guests in the Astronaut Encounter Theater at the Kennedy Space Center Visitor Complex in Florida. The pair participated in 50th anniversary events at the launch site of Glenn's first orbital flight aboard NASA's Friendship 7 capsule, which launched Feb. 20, 1962, aboard an Atlas rocket. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

S62-00993 (1962) --- Astronaut John H. Glenn Jr., pilot of the Mercury-Atlas 6 (MA-6) mission, practices insertion into the Mercury "Friendship 7" spacecraft during MA-6 preflight training activity at Cape Canaveral, Florida. He is wearing the full pressure suit and helmet. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Former space shuttle launch director, Bob Sieck, talks to guests in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. Sieck is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- Mercury astronauts, John Glenn, left, and Scott Carpenter, talk to Mercury Project workers and other guests in the Astronaut Encounter Theater at the Kennedy Space Center Visitor Complex in Florida. The pair participated in 50th anniversary events at the launch site of Glenn's first orbital flight aboard NASA's Friendship 7 capsule, which launched Feb. 20, 1962, aboard an Atlas rocket. At right, is Jack King, who was chief of Kennedy's Public Information Office during Project Mercury. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- John Glenn signs the wall of the clean room leading into space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- NASA Kennedy Space Center Director Bob Cabana talks to guests in Orbiter Processing Facility-1 OPF-1 where space shuttle Discovery is being prepared for public display during a 50th anniversary celebration of the first orbital flight of an American. The astronaut who made that first flight, John Glenn, is at the space center to commemorate that achievement. Glenn orbited the Earth three times in the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. He later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and his wife, Annie, and NASA astronaut Stephen Robinson stand under space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- NASA Kennedy Space Center Bob Cabana talks to a guest about the Mercury Project's Atlas rocket in the Vehicle Assembly Building. At the space center in Florida, Cabana is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- NASA Kennedy Space Center Director Bob Cabana sits at the controls in the flight deck of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1. At the space center in Florida, Cabana is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- Former space shuttle launch director, Bob Sieck, left, talks to guests in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. Sieck is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and his wife, Annie, and NASA astronaut Stephen Robinson tour the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn tours the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and his wife, Annie, and NASA astronaut Stephen Robinson stand under space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- NASA Kennedy Space Center Bob Cabana talks to guests about the Mercury Project's Atlas rocket in the Vehicle Assembly Building. At the space center in Florida, Cabana is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and his wife, Annie, and NASA astronaut Stephen Robinson stand under space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- Former space shuttle launch director, Bob Sieck, left, talks to guests in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. Sieck is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- Mercury astronauts, John Glenn, left, and Scott Carpenter, talk to Mercury Project workers and other guests in the Astronaut Encounter Theater at the Kennedy Space Center Visitor Complex in Florida. The pair participated in 50th anniversary events at the launch site of Glenn's first orbital flight aboard NASA's Friendship 7 capsule, which launched Feb. 20, 1962, aboard an Atlas rocket. At right, is Jack King, who was chief of Kennedy's Public Information Office during Project Mercury. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts, John Glenn, left, and Scott Carpenter, talk to Mercury Project workers and other guests in the Astronaut Encounter Theater at the Kennedy Space Center Visitor Complex in Florida. The pair participated in 50th anniversary events at the launch site of Glenn's first orbital flight aboard NASA's Friendship 7 capsule, which launched Feb. 20, 1962, aboard an Atlas rocket. At right, is Jack King, who was chief of Kennedy's Public Information Office during Project Mercury. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- John Glenn and NASA Kennedy Space Center Director Bob Cabana sit in the flight deck of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and his wife, Annie, and NASA astronaut Stephen Robinson stand beside the wheel of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and NASA astronaut Stephen Robinson sit in the flight deck of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- Hugh Harris, the former director of Public Affairs at NASA's Kennedy Space Center in Florida, talks to Mercury Project workers and other guests in the Astronaut Encounter Theater at the Kennedy Space Center Visitor Complex in Florida. Harris is helping Mercury astronauts, John Glenn and Scott Carpenter, mark the 50th anniversary of Glenn being the first American to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- NASA astronaut Stephen Robinson sits at the controls in the flight deck of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Robinson is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn stands in the middeck of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and NASA astronaut Stephen Robinson stand in the middeck of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn stands beside the wheel of space shuttle Discovery in Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

CAPE CANAVERAL, Fla. -- John Glenn and his wife, Annie, left, enter Orbiter Processing Facility-1 OPF-1 at NASA's Kennedy Space Center in Florida where space shuttle Discovery is being prepared for public display. Glenn is at the space center to mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

S62-00994 (1962) --- Astronaut John H. Glenn Jr., pilot of the Mercury-Atlas 6 mission, practices insertion into the Mercury "Friendship 7? spacecraft, with help of a McDonnell Aircraft Corporation technician, during MA-6 preflight training activity at Cape Canaveral, Florida. He is wearing the full pressure suit. Photo credit: NASA

CAPE CANAVERAL, Fla. -- NASA Kennedy Space Center Director Bob Cabana, right, talks to guests in Orbiter Processing Facility-1 OPF-1 where space shuttle Discovery is being prepared for public display during a 50th anniversary celebration of the first orbital flight of an American. The astronaut who made that first flight, John Glenn, is at the space center to commemorate that achievement. Glenn orbited the Earth three times in the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. He later returned to space in October 1998 as a payload specialist aboard Discovery's STS-95 mission. Also in the photo are Glenn's wife, Annie, NASA astronaut Stephen Robinson, and Bob Sieck, a former shuttle launch director. Robinson was the payload commander of STS-95. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Shuttle Discovery currently is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. Photo credit: Cory Huston

A plaque inside the Heroes and Legends exhibit hall at the Kennedy Space Center Visitor Complex shows astronaut Sen. John Glenn, along with his mission insignias for Friendship 7 and STS-95, the two flights he made into space. Glenn, who passed away Dec. 8, 2016 at age 95, was the last surviving member of NASA's original astronaut class. He gained worldwide acclaim during his Mercury mission that made him the first American to orbit the Earth. He flew again in 1998 aboard space shuttle Discovery at age 77.

S62-06012 (20 Feb. 1962) --- Orbital sunset photographed by astronaut John H. Glenn Jr. aboard the "Friendship 7" during his Mercury-Atlas 6 (MA-6) spaceflight. Photo credit: NASA

S62-06040 (20 Feb. 1962) --- Orbital sunset photographed by astronaut John H. Glenn Jr. aboard the "Friendship 7" during his Mercury-Atlas 6 (MA-6) spaceflight. Photo credit: NASA

Astronaut John H. Glenn Jr. uses binoculars to view the Earth through the window of the Mercury-Atlas (MA-6) Friendship 7 capsule during the U.S.'s initial orbital flight.

62-MA6-55 (1962) --- Astronaut John H. Glenn Jr., pilot of the Mercury Atlas 6 (MA-6) spaceflight, poses for a photo with the Mercury "Friendship 7" spacecraft during preflight activities. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Overall view of astronaut John H. Glenn Jr. as he commences entrance into spacecraft Friendship 7 prior to MA-6 launch operations. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Launch of Friendship 7, the first manned orbital space flight. Astronaut John Glenn aboard, the Mercury-Atlas rocket is launched from Pad 14. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Launch of Friendship 7, the first manned orbital space flight. Astronaut John Glenn aboard, the Mercury-Atlas rocket is launched from Pad 14. Photo credit: NASA

S62-06011 (20 Feb. 1962) --- Orbital sunset photographed by astronaut John H. Glenn Jr. aboard the "Friendship 7" during his Mercury-Atlas 6 (MA-6) spaceflight. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Astronaut John H. Glenn Jr. enters his Mercury capsule, "Friendship 7," as he prepares for launch of the Mercury-Atlas rocket. On February 20, 1962, Glenn lifted off into space aboard his Mercury Atlas 6 MA-6 rocket and became the first American to orbit the Earth. After orbiting the Earth 3 times, Friendship 7 landed in the Atlantic Ocean 4 hours, 55 minutes and 23 seconds later, just East of Grand Turk Island in the Bahamas. Glenn and his capsule were recovered by the Navy Destroyer Noa, 21 minutes after splashdown. Photo credit: NASA

S64-14848 (20 Feb. 1962) --- Astronaut John H. Glenn Jr. dons spacesuit during preflight operations at Cape Canaveral, Feb. 20, 1962, the day he flew his Mercury-Atlas 6 spacecraft, Friendship 7, into orbital flight around Earth. Photo credit: NASA

Sen. John Glenn's wife Annie listens to an interviewers question during a celebration dinner at The Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

Apollo 11 Astronaut Neil Armstrong speaks during a celebration dinner at Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

Sen. John Glenn and his wife Annie take the stage during a celebration dinner at The Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

Sen. John Glenn and his wife Annie take the stage during a celebration dinner at The Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

S62-01000 (20 Feb. 1962) --- Astronaut John H. Glenn Jr., pilot of the Mercury-Atlas 6 "Friendship 7" mission, looks over a checklist during MA-6 preflight activity. He is wearing his Mercury spacesuit. Photo credit: NASA

Sen. John Glenn talks on stage during a celebration dinner at The Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

S64-14854 (20 Feb. 1962) --- Astronaut John H. Glenn Jr. and technicians inspect a decal ready for application to the side of his Mercury spacecraft prior to launch on Feb. 20, 1962. The decal reads "Friendship 7". Photo credit: NASA

CAPE CANAVERAL, Fla. -- President John F. Kennedy honors John H. Glenn Jr. at Hangar S, Cape Canaveral, Florida, after his historic three-orbit mission aboard Friendship 7. Photo credit: NASA

S61-04546 (1961) --- Astronaut John H. Glenn Jr., pilot of the Mercury-Atlas 6 (MA-6) "Friendship 7" mission, takes part in spacecraft systems briefing during preflight activity at Cape Canaveral, Florida. Photo credit: NASA

S62-00371 (20 Feb. 1962) --- Mercury astronaut John H. Glenn Jr., pilot of the Mercury-Atlas 6 (MA-6) spaceflight, enters the Mercury "Friendship 7" spacecraft during the MA-6 prelaunch preparations at Cape Canaveral, Florida. Glenn became the first American to orbit Earth. Photo credit: NASA

CAPE CANAVERAL, Fla. -- President John F. Kennedy honors John H. Glenn Jr. at Hangar S, Cape Canaveral, Florida, after his historic three-orbit mission aboard Friendship 7. Photo credit: NASA

Sen. John Glenn and his wife Annie talk during a celebration dinner at The Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

S62-00965 (20 Feb. 1962) --- Astronaut John H. Glenn Jr., finishes suiting up, and prepares for the launch of his Mercury-Atlas 6 (MA-6) spacecraft. The MA-6 ?Friendship 7? mission marks America's first manned Earth-orbiting spaceflight. Photo credit: NASA

Sen. John Glenn and his wife Annie listen to speakers during a reception at Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

Apollo 11 Astronaut Neil Armstrong speaks during a celebration dinner at Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

Sen. John Glenn's wife Annie listens to an interviewers question during a celebration dinner at The Ohio State University honoring the 50th anniversary of John Glenn's historic flight aboard Friendship 7 Monday, Feb. 20, 2012, in Columbus, Ohio. Glenn was the first American to orbit Earth. Photo Credit: (NASA/Bill Ingalls)

CAPE CANAVERAL, Fla. -- U.S. Rep. Bill Posey listens to remarks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with John Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts John Glenn, second from left and Scott Carpenter look around at the dismantled Complex 14 at Cape Canaveral Air Force Station in Florida. Glenn and Carpenter launched from the pad on Atlas rockets inside Mercury capsules in 1962. The two astronauts, part of the original class of seven astronauts chosen by NASA, were taking part in events celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/ Cory Huston

CAPE CANAVERAL, Fla. --A crowd looks on during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with John Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronaut John Glenn speaks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. - Former Kennedy Space Center directors Jay Honeycutt, left, and Bob Crippen, right, talk during a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronaut John Glenn speaks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. - Former Kennedy Space Center directors Jay Honeycutt, left, Roy Bridges and NASA Administrator Charles Bolden talk with astronaut John Glenn before a luncheon Feb. 17, 2012 celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Former Kennedy Space Center directors Forrest McCartney, left, and Roy Bridges, center, listen with Annie Glenn during a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronaut Scott Carpenter speaks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with John Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- A crowd looks on during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with John Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. - Kennedy Space Center Director Bob Cabana, standing, speaks during a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts John Glenn, left, and Scott Carpenter sit in front of the plot board from the Mercury control center on display at the Kennedy Space Center Visitor Complex. The astronauts, part of the original class of seven astronauts chosen by NASA, were taking part in a question-and-answer session with the media as part of events celebrating 50 years of Americans in orbit, an era which began with John Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. --Mercury astronaut John Glenn listens to remarks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. - Ed Mango, program manager of NASA's Commercial Crew Program, left, talks with astronaut John Glenn, center and NASA Administrator Charles Bolden before a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts Scott Carpenter, left, and John Glenn listen to remarks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts Scott Carpenter, left, and John Glenn and astronaut Steve Robinson of STS-95 listen to remarks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. - Former Kennedy Space Center directors Forrest McCartney and Roy Bridges join Annie Glenn, astronaut John Glenn and NASA Administrator Charles Bolden during a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-95 astronaut Steve Robinson speaks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with John Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts Scott Carpenter, left, and John Glenn sit in front of a capsule from the Mercury program on display at the Kennedy Space Center Visitor Complex in Florida. The two astronauts, part of the original class of seven astronauts chosen by NASA, were taking part in events celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - NASA Administrator Charles Bolden, left, shares a laugh with astronaut John Glenn before a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronauts Scott Carpenter, left, and John Glenn and astronaut Steve Robinson of STS-95 listen to remarks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- U.S. Rep. Bill Posey, left, prepares to ride in the Corvette parade following the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- John Zarella makes remarks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with John Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Cal Fowler, Launch test director during Mercury, speaks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with John Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronaut Scott Carpenter, center, prepares to ride in the Corvette parade following the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett

CAPE CANAVERAL, Fla. -Annie Glenn and astronaut John Glenn listen during a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronaut John Glenn sits in front of the plot board from the Mercury control center on display at the Kennedy Space Center Visitor Complex in Florida. The astronaut, part of the original class of seven astronauts chosen by NASA, was taking part in a question-and-answer session with the media as part of events celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mercury astronaut John Glenn speaks during the "On Shoulders of Giants" program celebrating 50 years of Americans in orbit, an era which began with Glenn's MA-6 mission on Feb. 20, 1962. The event was conducted in the Rocket Garden at the Kennedy Space Center Visitor Complex in Florida a few miles from the launch pad where Glenn and Scott Carpenter took flight in Mercury spacecraft. Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: Kim Shiflett