Former Ohio Sen. John Glenn, the first American astronaut to orbit the Earth, has died at the age of 95. 

Glenn had been hospitalized since last week at The James Cancer Hospital at Ohio State University in Columbus. His health had declined in recent years — he had been losing his eyesight, and had undergone open-heart surgery in 2014.

John Herschel Glenn Jr. served four terms as a Democratic senator from Ohio from 1975 to 1999. He is best remembered for his career as an astronaut — particularly as one of the Mercury 7 — and as the first American to orbit the Earth in 1962, a feat that, at the time, turned him into a national hero and triumphant symbol of American enterprise.

Glenn was born in Cambridge, Ohio, on July 18, 1921. He received an engineering degree from Muskingum University in New Concord, Ohio in 1939. Following the Japanese attack on Pearl Harbor in 1941, he enlisted in the Army and in 1942, joined the Naval Aviation Cadet Program where he received naval air training. Glenn spent the majority of World War II flying 59 combat missions for the Marine Corps in the Pacific Theater, and by its end, he had been promoted to the rank of captain. During the war, he married his childhood sweetheart, Annie Castor, in 1943.

After the war, Glenn was a member of Marine Fighter Squadron 218 on the North China patrol based in Guam, until the outbreak of the Korean War, when he continued to fly combat missions. One of his co-pilots in Korea was future Boston Red Sox great Ted Williams. At the conclusion of that war, he became a test pilot and in 1957, set a transcontinental supersonic speed record as part of “Project Bullet,” flying from Los Angeles to New York in 3 hours, 23 minutes and 8.4 seconds. This record gained Glenn much attention and publicity, leading to NASA’s selection of him for the Project Mercury astronaut program.

Along with fellow test pilots Scott Carpenter, Gordon Cooper, Gus Grissom, Alan Shepard, Wally Schirra and Deke Slayton, Glenn was one of the Mercury 7 astronauts. A main propaganda tool of the space race, NASA’s Project Mercury ran from 1959 to 1963 with the goal of putting a human in orbit before the Soviet Union. Glenn accomplished that goal, becoming the first American to orbit the Earth in his capsule Friendship 7 on Feb. 20, 1962. Glenn and his fellow astronauts were also instrumental in the development of the Mercury capsules, demanding an active role in the design. Tom Wolfe chronicled the exploits of the Mercury astronauts (as well as those of sound barrier test pilot Chuck Yeager) in his 1979 book “The Right Stuff” (adapted by Philip Kaufman into a 1983 film, in which Ed Harris memorably played Glenn.). Glenn was the last surviving Mercury 7 member.

Glenn became a national celebrity during the Mercury program, receiving a hero’s welcome after his orbit with a ticker-tape parade in New York City and the Distinguished Service Medal from President John F. Kennedy. Following his retirement from the space program in 1964, he turned his attention toward public service, making his first run for one of Ohio’s Senate seats. A head injury resulting from a slip in his bathroom, however, forced him to withdraw from that race. In 1970, he ran for the Senate again, losing narrowly to Howard Metzenbaum in the Democratic primary (Metzenbaum lost in the general election to Robert Taft Jr.).

Glenn challenged Metzenbaum again in 1974, defeating him in that year’s Democratic Senate primary, thanks in part to his “Gold Star Mothers” speech: During the campaign, Metzenbaum accused Glenn of never earning a proper living, having served in the military for his entire career. Glenn countered by telling Metzenbaum to say that to a wounded veteran and his “Gold Star” mother. The speech helped put Glenn over the top in the primary, and in the general election, he defeated Cleveland Mayor Ralph Perk. Glenn would go onto to serve Ohio in the Senate until 1999, the longest senatorial tenure in Ohio history.

Glenn’s Senate career was overshadowed somewhat by his involvement as one of the “Keating Five” in the infamous Savings and Loan Crisis of the 1980s, the result of deregulation of the savings and loan industry, and high-risk investments with depositors’ money. This led to rampant speculation, the catalyst being the Lincoln Savings and Loan Association — one of the largest S&Ls — headed by Charles Keating, whose malfeasance caused its bankruptcy in 1989, resulting in a chain reaction of other S&Ls to fail. The subsequent financial crisis led to millions of depositors losing their savings, at the initial cost of over $3 billion in bailout money to the federal government (and taxpayers). The investigation by the Federal Home Loan Bank Board revealed that Keating — who was eventually convicted on numerous counts of conspiracy, fraud, and racketeering — had given more than $200,000 in campaign contributions and gifts to five senators in return for helping to cover up Lincoln’s role in the crisis: Democrats Alan Cranston of California, Dennis DeConcini of Arizona, Glenn, Donald W. Riegle of Michigan, and Republican John McCain of Arizona. The Senate Ethics determined that of the five, only Cranston, DeConcini, and Riegle had improperly interfered with the investigation. Glenn and McCain, they concluded, had merely used “poor judgment.” Both were exonerated and re-elected in their next terms.

Despite his involvement in the “Keating Five” scandal, Glenn had a long and distinguished senatorial and political career. In the 1976 presidential election, he was considered by Jimmy Carter for vice president, losing out to Walter Mondale. He ran for president in 1984 — capitalizing on the then-recent popularity of the “Right Stuff” film— losing to Mondale in the Democratic primary.

During his tenure in the Senate, Glenn served as chairman of the Committee on Governmental Affairs from 1987 to 1995, and sat on the Foreign Relations and Armed Services committees and the Special Committee on Aging. He also authored the Nuclear Non-Proliferation Act of 1978. Passed by the 95th Congress and signed into law by Carter on March 10, 1978, the act required countries to belong to the Nuclear Nonproliferation Treaty in order to receive U.S. nuclear exports, which helped the U.S. limit and control nuclear weapons. Also in 1978, Congress awarded him the Congressional Space Medal of Honor.

On October 1998, Glenn returned to space, flying on the Space Shuttle Discovery as part of a NASA experiment to examine age in space (an experiment for which he was an active lobbyist). His participation in that mission created new milestones as it made him not only the oldest person to fly into space (he was 77 at the time) but also the only active member of Congress to go into space as well.

Also in 1998, Glenn helped establish the Institute for Public Service and Public Policy (now the John Glenn School of Public Affairs) at Ohio State University, where he also held an honorary professor title. Following his retirement from the Senate, he and Annie lived together as private citizens of Columbus, Ohio. In 2011, Congress awarded him — along with Apollo astronauts Michael Collins, Buzz Aldrin, and Neil Armstrong — the Congressional Gold Medal. In 2012, President Barack Obama awarded him the Presidential Medal of Freedom.

Astronaut, senator, pilot, politician, pioneer, teacher, and hero: John Glenn will be remembered as being all these. He is survived by his wife Annie, son John David, daughter Carolyn Ann (Lyn), and two grandchildren.