S64-40113 (1964) --- Astronaut Walter Schirra Jr. (right) and Walter Williams, Deputy Director of Mission Requirements, pictured at the Mercury 7 memorial dedication. Photo credit: NASA

S62-03266 (24 May 1962) --- Earth and sky views taken with hand-held camera by astronaut M. Scott Carpenter during Mercury-Atlas 7 (MA-7) mission. Photo credit: NASA

S62-03270 (24 May 1962) --- Earth and sky views taken with hand-held camera by astronaut M. Scott Carpenter during Mercury-Atlas 7 (MA-7) mission. 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

62-MA7-169 (1962) --- John Glenn congratulates Scott Carpenter (left) on his three-orbit mission aboard the Aurora 7 spacecraft. Photo credit: NASA

62-MA7-123 (1962) --- Scott Carpenter (foreground) demonstrates a point to John Glenn while relaxing after his three-orbit MA-7 spaceflight. 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

S62-03250 (24 May 1962) --- Earth and sky views taken with hand-held camera by astronaut M. Scott Carpenter during Mercury-Atlas 7 (MA-7) mission. Photo credit: NASA

62-MA7-86 (1962) --- John Glenn (left) makes last minute preparations with Scott Carpenter prior to the flight of MA-7. Photo credit: NASA

S62-03248 (24 May 1962) --- Earth and sky views taken with hand-held camera by astronaut M. Scott Carpenter during Mercury-Atlas 7 (MA-7) mission. Photo credit: NASA

S62-03257 (24 May 1962) --- Earth and sky views taken with hand-held camera by astronaut M. Scott Carpenter during Mercury-Atlas 7 (MA-7) mission. Photo credit: NASA

This image, from NASA Mariner 10 spacecraft which launched in 1974, is of the H-7 Beethoven Quadrangle, and lies in Mercury Equatorial Mercator. NASA Mariner 10 spacecraft imaged the region during its initial flyby of the planet.

S62-00120 (1961) --- Astronaut M. Scott Carpenter, prime pilot for the Mercury-Atlas 7 (MA-7) spaceflight, is seen in Hangar S crew quarters during a suiting exercise at Cape Canaveral, Florida. Photo credit: NASA

Astronaut Alan B. Shepard, Jr. lifts off in the Freedom 7 Mercury spacecraft on May 5, 1961. This third flight of the Mercury-Redstone (MR-3) vehicle, developed by Dr. Wernher von Braun and the rocket team in Huntsille, Alabama, was the first marned space mission for the United States. During the 15-minute suborbital flight, Shepard reached an altitude of 115 miles and traveled 302 miles downrange.

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.

The launch of the Mercury-Redstone (MR-3), Freedom 7. MR-3 placed the first American astronaut, Alan Shepard, in suborbit on May 5, 1961.

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 L. Gordon Cooper, Jr., one of the original seven astronauts for Mercury Project selected by NASA on April 27, 1959. The MA-9 mission, boosted by the Mercury-Atlas launch vehicle, was the last flight of the Mercury Project. The Faith 7 spacecraft orbited the Earth 22 times in 1-1/2 days.

The MA-7 Booster ignites on the pad and is seconds away from actual liftoff. Aboard the spacecraft is Astronaut M. Scott Carpenter, the U.S. second man to orbit the Earth. CAPE CANAVERAL, FL CN

Astronaut Alan B. Shepard, one of the original seven astronauts for Mercury Project selected by NASA on April 27, 1959. The Freedom 7 spacecraft boosted by Mercury-Redstone vehicle for the MR-3 mission made the first marned suborbital flight and Astronaut Shepard became the first American in space.

S62-02846 (24 May 1962) --- Project Mercury astronaut M. Scott Carpenter, prime pilot for the Mercury-Atlas 7 (MA-7) mission, is assisted into the MA-7 spacecraft by techicians at Launch Pad 14, Cape Canaveral, Florida. MA-7 is the United States? second attempt in orbital flight around Earth. The spacecraft was designated the ?Aurora? 7. Photo credit: NASA

Astronaut Walter M. "Wally" Schirra, one of the original seven astronauts for Mercury Project selected by NASA on April 27, 1959. The MA-8 (Mercury-Atlas) mission with Sigma 7 spacecraft was the third marned orbital flight by the United States, and made the six orbits in 9-1/4 hours.

Astronaut Alan Shepard underwent a physical examination prior to the first marned suborbital flight. Freedom 7 carrying Astronaut Alan Shepard, boosted by the Mercury-Redstone launch vehicle, lifted off on May 5, 1961. Astronaut Shepard became the first American in space.

Astronaut Alan B. Shepard, Jr. during suiting for the first manned suborbital flight, MR-3 mission. The Freedom 7 spacecraft, carrying the first American, Astronaut Shepard and boosted by the Mercury-Redstone launch vehicle, lifted off on May 5, 1961.

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

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.

Liftoff of MR-4 (Mercury-Redstone), Liberty Bell 7, on July 21, 1961. MR-4 mission was the second marned suborbital flight and carried Astronaut Virgil Grissom aboard the Liberty Bell 7 spacecraft in space for a duration of 15-1/2 minutes.

S64-40111 (1964) --- Wide angle view of the Mercury 7 memorial dedication. Photo credit: NASA

S62-06006 (3 Oct. 1962) --- Launch of the Mercury-Atlas 8 "Sigma 7" mission. Photo credit: NASA

S62-04018 (24 May 1962) --- Astronaut M. Scott Carpenter is inserted inside his Aurora 7 spacecraft, before the launch of the Mercury-Atlas 7 (MA-7) mission. Photo credit: NASA

This photo depicts the recovery operations of the MR-3 mission. Astronaut Alan Shepard was picked up by a U.S. Marine helicopter after the completion of the first marned suborbital flight by MR-3 (Mercury-Redstone) with the Freedom 7 capsule.

S62-02852 (1962) --- Astronaut M. Scott Carpenter, prime pilot for the Mercury-Atlas 7 (MA-7) mission, goes through a water egress training session. Photo credit: NASA

CAPE CANAVERAL, Fla. - Kennedy Space Center Director Bob Cabana, from left, Mercury astronaut John Glenn, NASA Administrator Charles Bolden and Mercury astronaut Scott Carpenter pose 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, 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. -- 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. -- 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

S62-03907 (24 May 1962) --- Astronaut M. Scott Carpenter looks into his Mercury-Atlas 7 spacecraft, the Aurora 7, before being inserted to begin the launch. Photo credit: NASA

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.

The recovery operation of the Faith 7 spacecraft after the completion of the 1-1/2 day orbital flight (MA-9 mission) with Astronaut Gordon Cooper. Navy frogmen attach the flotation collar to the spacecraft. The MA-9 mission was the last flight of the Mercury Project and launched on May 15, 1963 boosted by The Mercury-Atlas launch vehicle.

CAPE CANAVERAL, Fla. - Mercury astronaut John Glenn, left, talks with Kennedy Space Center Director Bob Cabana 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 signs a poster 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 pose 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 signs a poster 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 Mercury astronaut Scott Carpenter, left, and former Kennedy Space Center directors Jay Honeycutt, Bob Crippen, Forrest McCartney and Roy Bridges 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 Scott Carpenter and his wife, Patricia, pose during a luncheon Feb. 17, 2012, 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, 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 and his wife, Annie, pose 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. -- 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 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

Astronaut Alan Shepard fitted with space suit prior to the first marned suborbital flight. Freedom 7, carrying Astronaut Alan Shepard, boosted by the Mercury-Redstone launch vehicle, lifted off on May 5, 1961. Astronaut Shepard became the first American in space.

A U.S. Marine helicopter attempts to retrieve the sinking capsule, Liberty Bell 7, of the MR-4 mission. The attempt failed and the capsule sank. The MR-4 mission marned by Astronaut Virgil Grissom was the second manned orbital flight boosted by the Mercury-Redstone vehicle. The Recovery ship is in the background.

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.

S62-05529 (24 May 1962) --- The Mercury-Atlas 7 (MA-7), carrying astronaut M. Scott Carpenter, was launched by NASA from Pad 14, Cape Canaveral, Florida, on May 24, 1962. Photo credit: NASA

S62-02849 (24 May 1962) --- The Mercury-Atlas 7 (MA-7), carrying astronaut M. Scott Carpenter, was launched by NASA from Pad 14, Cape Canaveral, Florida, on May 24, 1962. Photo credit: NASA

S62-07872 (3 Oct. 1962) --- Launch of the Mercury-Atlas 8 (MA-8) "Sigma 7" mission, carrying astronaut Walter M. Schirra Jr., pilot of the Earth-orbital spaceflight. Photo credit: NASA

Astronaut Virgil I. "Gus" Grissom, one of the original seven astronauts for Mercury Project selected by NASA on April 27, 1959. The MR-4 mission, boosted by the Mercury-Redstone vehicle, made the second marned suborbital flight. The capsule, Liberty Bell 7, sank into the sea after the splashdown.

CAPE CANAVERAL, Fla. -- Mercury astronaut John Glenn, left, talks with fellow Mercury astronaut Scott Carpenter before they 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. -- Mercury astronaut John Glenn poses in front of the Mercury 7 memorial near 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. - 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. - 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. -- 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. - 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. - 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. - 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. -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. -Annie Glenn, left, astronaut John Glenn and NASA Administrator Charles Bolden take part in 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. - Annie Glenn, center, speaks as former Kennedy Space Center director Roy Bridges, left, and astronaut John Glenn look on 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. - NASA Administrator Charles Bolden, left, talks with astronaut John Glenn and his wife, Annie 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. -NASA Administrator Charles Bolden, left, talks with astronaut John Glenn following 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

S61-01928 (5 May 1961) --- Mercury-Redstone 3 (MR-3), the United States' first manned spaceflight, is launched from Cape Canaveral on a suborbital mission. Astronaut Alan B. Shepard Jr. was the pilot of the Mercury spacecraft, designated "Freedom 7". The spacecraft attained a maximum speed of 5,180 miles per hour (mph), reached an altitude of 116 1/2 statute miles, and landed 302 statute miles downrange from Cape Canaveral, Florida. Photo credit: NASA or National Aeronautics and Space Administration

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. -- 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 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. -- 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. -- 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. -- 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

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. -- 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. -- 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. --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