S62-01004 (1962) --- Astronaut John H. Glenn Jr., pilot of the Mercury Atlas 6 (MA-6) mission, participates in Mercury egress training during MA-6 preflight preparations. Glenn made the free world's first manned Earth-orbital flight on Feb. 20, 1962. Photo credit: NASA

S62-00379 (20 Feb. 1962) --- View of astronaut John H. Glenn Jr., Dr. William Douglas, astronauts' flight surgeon, and equipment specialist Joe Schmitt leaving Operations and Checkout Building prior to the Mercury-Atlas 6 (MA-6) mission. Glenn is in his pressure suit and is carrying the portable ventilation unit. 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 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.

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.

January 1962 -- Project Mercury Astronaut John H. Glenn Jr., prime pilot for the MA-6 mission, takes a work-out in the procedures trainer in preparation for the flight.

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

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

S62-00330 (1962) --- Astronaut John H. Glenn Jr. (left), Dr. William Douglas, astronauts flight surgeon, and equipment specialist Joe Schmitt leave crew quarters prior to Mercury-Atlas 6 (MA-6) mission. Glenn is in his pressure suit and is carrying the portable ventilation unit. Photo credit: NASA

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.

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

S62-00377 (20 Feb. 1962) --- Astronaut John H. Glenn Jr., walking out of building with Dr. William K. Douglas (to Glenn's left), and Joe W. Schmitt, NASA's suit technician (in front of Dr. Douglas). This Mercury Atlas 6 (MA-6) ?Friendship 7? flight marks America's first manned Earth-orbiting spaceflight. 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

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.

S62-00966 (20 Feb. 1962) --- Astronaut John H. Glenn Jr. (center) eats breakfast the morning of the launch of his Mercury-Atlas 6 (MA-6)spacecraft. Dr. William K. Douglas is at right. Photo credit: NASA

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

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

S64-10801 (1962) --- Astronauts M. Scott Carpenter (far left) and John H. Glenn Jr. relax following breakfast during Mercury Atlas 6 (MA-6) preflight activity. Glenn is the MA-6 pilot. Carpenter is the MA-6 backup pilot. Photo credit: NASA

S62-00222 (20 Feb. 1962) --- View of astronaut John H. Glenn Jr. and equipment specialist Joe Schmitt leaving crew quarters prior to Mercury-Atlas 6 (MA-6) mission. Glenn is in his pressure suit and is carrying the portable ventilation unit. Photo credit: NASA

S64-14869 (February 1962) --- Astronaut John H. Glenn Jr., wearing a Mercury pressure suit, was the pilot of the Mercury-Atlas 6 (MA-6) mission. Glenn made America's first manned Earth-orbital spaceflight on Feb. 20, 1962. This photograph was taken at Cape Canaveral, Florida, during MA-6 preflight training activities. Photo credit: NASA

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

S64-10761 (1962) --- Astronauts Virgil I. (Gus) Grissom (left) and John H. Glenn Jr. hold a discussion in the Mercury Control Center during Mercury-Atlas 6 preflight activity. Glenn is the MA-6 pilot. Grissom was the pilot for the Mercury-Redstone 4 spaceflight made on July 21, 1961. Photo credit: NASA

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

S72-41853 (15 June 1972) --- Two members of the three-man Skylab Medical Experiment Altitude Test (SMEAT) crew, that will spend up to 56 days in the Crew Systems Division's 20-foot altitude chamber at the Manned Spacecraft Center (MSC) beginning in mid-July, go over a menu in the food preparation area. Seated at the simulated wardroom food table is astronaut Karol J. Bobko, SMEAT pilot, and standing is astronaut Robert L. Crippen, SMEAT commander. Dr. William E. Thornton, SMEAT science pilot, the third crew member is not shown in this view. Photo credit: NASA

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.

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. -- 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, 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

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.

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. -- Mercury astronaut Scott Carpenter 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 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. - 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. --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. -- 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

AS08-16-2584 (21 Dec. 1968) --- This is a photograph taken from the Apollo 8 spacecraft looking back at the Saturn V third (S-IVB) stage from which the spacecraft had just separated following trans-lunar injection. Attached to the S-IVB is the Lunar Module Test Article (LTA) which simulated the mass of a Lunar Module (LM) on the Apollo 8 lunar orbit mission. The 29-feet panels of the Spacecraft LM Adapter which enclosed the LTA during launch have already been jettisoned and are out of view. Sunlight reflected from small particles shows the "firefly" phenomenon which was reported by astronaut John H. Glenn Jr. during the first Earth-orbital flight, Mercury-Atlas 6 (MA-6) of the Mercury Program.

AS08-16-2583 (21 Dec. 1968) --- This is a photograph taken from the Apollo 8 spacecraft looking back at the Saturn V third (S-IVB) stage from which the spacecraft had just separated following trans-lunar injection. Attached to the S-IVB is the Lunar Module Test Article (LTA) which simulated the mass of a Lunar Module (LM) on the Apollo 8 lunar orbit mission. The 29-feet panels of the Spacecraft LM Adapter which enclosed the LTA during launch have already been jettisoned and are out of view. Sunlight reflected from small particles shows the "firefly" phenomenon which was reported by astronaut John H. Glenn Jr. during the first Earth-orbital flight, Mercury-Atlas 6 (MA-6) of the Mercury Program.

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. - 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. -- The international news media takes part in a question-and-answer session with Mercury astronauts John Glenn and Scott Carpenter at the Kennedy Space Center Visitor Complex in Florida. The 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 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. - 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

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

B60-00285 (1960) --- Astronaut John H. Glenn Jr., pilot of the Mercury Atlas 6 spaceflight, emerges from an egress trainer during training activity at the Langley Research Center. He is attempting to transfer onto a life raft from the mock-up of the Mercury capsule. Photo credit: NASA

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

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. -- 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. -- 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. -- 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, 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. -- Mercury astronaut Scott Carpenter 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 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: Cory Huston

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 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. -- Astronaut Steve Robinson of STS-95, left, Cal Fowler, Launch test director during Mercury, U.S. Rep. Bill Posey, U.S. Sen. Bill Nelson and Kennedy Space Center Director Bob Cabana listen 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 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

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 Scott Carpenter, 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 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 John Glenn, left, and Kennedy Space Center Director Bob Cabana shake hands 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. --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 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. -- 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. -- Lisa Malone, left, director of Public Affairs at NASA's Kennedy Space Center in Florida, talks with Mercury astronauts John Glenn, center, and Scott Carpenter 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 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 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 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 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 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 astronauts John Glenn, 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. - Former Kennedy Space Center directors Forrest McCartney, from left, Bob Crippen, Jay Honeycutt and Roy Bridges stand with current Kennedy director Bob Cabana, Mercury astronauts John Glenn and Scott Carpenter 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. -- 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. -- 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. -- 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. --Kennedy Space Center Director Bob Cabana, 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 leads a standing ovation 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 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. Looking on are U.S. Rep. Bill Posey, left, and event MC John Zarella. 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. -- U.S. Sen. Bill Nelson 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. -- Kennedy Space Center Director Bob Cabana 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. -- Kennedy Space Center Director Bob Cabana, center, talks with U.S. Rep. Bill Posey, left and U.S. Sen. Bill Nelson 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. -- 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