John Glenn, who became one of the 20th century’s greatest explorers as the first American to orbit Earth and later as the world’s oldest astronaut, in addition to a long career as a U.S. senator, died on Thursday at age of 95. [Astronaut John Glenn: An American Hero's Monumental Career Remembered]

John Glenn became the first NASA astronaut to orbit the Earth in 1962 during his Friendship 7 mission, which was part of NASA's Project Mercury spaceflight program. Glenn died at the James Cancer Hospital in Columbus, Ohio, where he was hospitalized for more than a week, said Hank Wilson, communications director for the John Glenn School of Public Affairs. (Chris Hondros/Getty Images)

Former astronaut and former U.S. Sen. John Glenn (D-OH) is presented with a Presidential Medal of Freedom by U.S. President Barack Obama during an East Room event May 29, 2012 at the White House in Washington, DC. Reaching speeds of more than 17,000 miles per hour, he circled the globe three times in just under five hours in the Friendship 7 capsule. The Soviet Union leaped ahead in space exploration by putting the Sputnik 1 satellite in orbit in 1957, and then launched the first man in space, cosmonaut Yuri Gagarin, in a 108-minute orbital flight on April 12, 1961. He then spent 24 years as a Democratic senator from Ohio and briefly made a run for president in 1984
• John Glenn, first US astronaut to orbit Earth, dies aged 95 His long political career enabled him to return to space in the shuttle Discovery at age 77 in 1998, a cosmic victory lap that he relished and turned into a teachable moment about growing old.
American astronaut John Glenn dies at the age of 95.