This was approved, and Glenn was posted to VMO-155 on July 2, 1943, two days before the squadron moved to Marine Corps Air Station El Centro in California.

[36][37] Glenn moved his family back to New Concord during a short period of leave, and after two and a half months of jet training at Cherry Point, was ordered to South Korea in October 1952, late in the Korean War.

[43][44] He flew for a time with Marine reservist Ted Williams (then in the midst of a Hall of Fame baseball career with the Boston Red Sox) as his wingman.

[47] In June 1953, Glenn reported for duty with the USAF's 25th Fighter-Interceptor Squadron and flew 27 combat missions in the F-86, a much faster aircraft than the F9F Panther, patrolling MiG Alley.

[50] Glenn later wrote, "Since the days of the Lafayette Escadrille during World War I, pilots have viewed air-to-air combat as the ultimate test not only of their machines but of their own personal determination and flying skills.

[64] At that time, the transcontinental speed record, held by an Air Force Republic F-84 Thunderjet, was 3 hours 45 minutes and Glenn calculated that the F8U Crusader could do it faster.

His office was asked to send a test pilot to Langley Air Force Base in Virginia to make runs on a spaceflight simulator, as part of research by the newly formed NASA into re-entry vehicle shapes.

The pilot would also be sent to the Naval Air Development Center in Johnsville, Pennsylvania, and would be subjected to high G-forces in a centrifuge for comparison with data collected in the simulator.

McDonnell engineers told him of the importance of lightening the vehicle as much as possible, so Glenn began exercising to lose the 30 pounds (14 kg) by which he estimated he was overweight.

[74] This was fortunate for Glenn, who barely met the requirements, as he was near the age cutoff and lacked a science-based degree,[62] but had taken more classes since leaving college than needed for graduation.

[76] Because of his Bureau of Aeronautics job, Glenn was already participating in Project Mercury; while other candidates were at Wright, on March 17 he and most of those who would choose the astronauts visited the McDonnell plant building the spacecraft to inspect its progress and make changes.

[64] The identities of the seven were announced at a press conference at Dolley Madison House in Washington, D.C., on April 9, 1959:[78] Scott Carpenter, Gordon Cooper, Glenn, Gus Grissom, Wally Schirra, Alan Shepard, and Deke Slayton.

"[80] The magnitude of the challenge ahead of them was made clear a few weeks later, on the night of May 18, 1959, when the seven astronauts gathered at Cape Canaveral to watch their first rocket launch, of an SM-65D Atlas, which was similar to the one that was to carry them into orbit.

"[81] Glenn remained an officer in the Marine Corps after his selection,[82] and was assigned to the NASA Space Task Group at Langley Research Center in Hampton, Virginia.

The retrorocket pack broke up into large chunks of flaming debris that flew past the window of his capsule during re-entry; Glenn thought this might have been the heat shield.

As it seemed unlikely that he would be selected for Project Apollo missions,[72] he resigned from NASA on January 16, 1964, and announced his Democratic Party candidacy for the U.S. Senate from his home state of Ohio the following day,[116] becoming the first astronaut-politician.

[119] In late February he was hospitalized for a concussion sustained in a fall against a bathtub while attempting to fix a mirror in a hotel room;[120] an inner-ear injury from the accident left him unable to campaign.

Businessman Howard Metzenbaum, Young's former campaign manager, was backed by the Ohio Democratic party and major labor unions, which provided him a significant funding advantage over Glenn.

[159] One reviewer said that "Harris' depiction helped transform Glenn from a history-book figure into a likable, thoroughly adoration-worthy Hollywood hero," turning him into a big-screen icon.

[163] After Mondale defeated him for the nomination, Glenn carried $3 million in campaign debt for over 20 years before receiving a reprieve from the Federal Election Commission.

Glenn was made aware of the problem at the Fernald Feed Materials Production Center near Cincinnati and soon found that it affected sites across the nation.

[194] When the Republican Party regained control of the Senate in 1996, Glenn became the ranking minority member on the Permanent Subcommittee on Investigations until he was succeeded by Carl Levin.

Given the loss of radar listening posts in Iran, Glenn did not believe that the U.S. had the capability to monitor the Soviet Union accurately enough to verify compliance with the treaty.

On January 16, 1998, NASA Administrator Dan Goldin announced that Glenn would be part of the STS-95 crew;[215] this made him, at age 77, the oldest person to fly in space at that time.

On October 15, 1998, NASA Road 1 (the main route to the Johnson Space Center) was temporarily renamed John Glenn Parkway for several months.

[235] To commemorate the 50th anniversary of the Friendship 7 flight on February 20, 2012, he had an unexpected opportunity to speak with the orbiting crew of the International Space Station when he was onstage with NASA Administrator Charlie Bolden at Ohio State University.

[236] On April 19, 2012, Glenn participated in the ceremonial transfer of the retired Space Shuttle Discovery from NASA to the Smithsonian Institution for permanent display at the Steven F. Udvar-Hazy Center.

[36][302][301] Buzz Aldrin wrote that Glenn's Friendship 7 flight "... helped to galvanize the country's will and resolution to surmount significant technical challenges of human spaceflight.

John spent his life breaking barriers, from defending our freedom as a decorated Marine Corps fighter pilot in World War II and Korea, to setting a transcontinental speed record, to becoming, at age 77, the oldest human to touch the stars.

[305] NASA administrator Charles Bolden said: "Senator Glenn's legacy is one of risk and accomplishment, of history created and duty to country carried out under great pressure with the whole world watching".