By the time he lifted off for the moon in the summer of 1969, Neil Armstrong's official administrative status was that of a U.S. federal civil servant earning the top white-collar scale pay of $30,054 (U.S.) a year.
But he had already spent two decades risking his life, getting shot at by North Korean gunners, ejecting from a crippled jet, flying a supersonic rocket plane and being trapped in a space capsule tumbling wildly in orbit.
Then, as much thanks to his flying talent as by dint of luck, he was picked to be on the historic Apollo 11 mission that first landed on the moon.
A look back at that lesser-known, earlier part of his life underlines the giant technical leaps that humankind performed in less than a century as it moved from the baby steps of aviation to the first human steps on another celestial body.
Of all Mr. Armstrong's pre-lunar achievements, space travel experience was the most limited qualification for the 38-year-old pilot from Wapakoneta, Ohio.
Today's space travellers benefit from sophisticated simulators and often rack up extensive time in orbit – from a week to several months – before they command a mission.
Mr. Armstrong had only spent a grand total of 10 hours, 41 minutes and 26 seconds in space when he was picked to lead the Apollo 11.
Nevertheless, he had been a naval aviator during the Korean war and he had tested the fastest manned aircraft ever flown, the X-15 rocket plane.
Mr. Armstrong's first plane ride, when he was six, was in a propeller-engine Ford Tri-Motor, the first American airliner and one of the first all-metal aircraft, first built in 1926.
He caught the flying bug and, just a year after the end of the Second World War, a 16-year-old Mr. Armstrong had earned his student pilot's license, before he even had taken his car driver's test.
By then, jet engines were more common and the Korean War a few years later was the first major conflict where fighting in the air mainly involved jet planes.
Mr. Armstrong, who was studying engineering on a U.S. Navy scholarship, was called to duty and flew combat missions from the aircraft carrier U.S.S. Essex.
During a strafing run in September 1951, Ensign Armstrong was flying a Grumman F9F Panther when he was hit by North Korean anti-aircraft fire. Trying to evade the flak, he struck a cable strung across a valley, shearing off about six feet from his right wing.
He managed to fly back to friendly territory before ejecting near a Marines airbase.
"I didn't know what the stalling speed would be, but felt uncomfortable at less than 200 knots, where nearly full aileron was required for level flight. So I jumped out," he wrote years later in a typically laconic note to the book author Patricia Francis, who asked about the incident.
After leaving the military in 1952, Mr. Armstrong became a test pilot for NACA, the National Advisory Committee for Aeronautics, the predecessor of the National Aeronautics and Space Administration (NASA).
He was based at the Flight Research Center in Edwards, California, a now legendary testing ground for hypersonic aircraft.
Starting in 1960, he was part of the program testing the X-15, a revolutionary needle-shaped rocket plane that was hoisted into the air under a bomber's wing.
The X-15 pilots would blast their plane to speeds of five to six times the speed of sound, climbing to the edge between Earth's atmosphere and space, then gliding down to the ground.
The program collected crucial data that would later help develop the space shuttle.
Mr. Armstrong flew the X-15 seven times, reaching a maximum speed of Mach 5.74.
"A balance of pilot skills and engineering; that was the ticket ... Neil Armstrong was typical of the new breed," Tom Wolfe wrote in The Right Stuff, a classic book about the first days of space exploration.
"His expression hardly ever changed, You'd ask him a question and he would just stare at you with those pale-blue eyes of his, and you'd start to ask the question again, figuring he hadn't understood, and – click – out of his mouth would come forth a sequence of long, quiet, perfectly formed, precisely thought-out sentences...
"The new breed had their shares of the proper righteous stuff, same as the stick 'n' rudder tigers of yore. Armstrong himself had flown  missions off carriers during the Korean War, and had done good work on the X-15."
But by 1962 he had applied to join a new, fledgling endeavour – NASA's manned space flight. The year before, then president John F. Kennedy had given a historic speech pledging to put an American on the moon.
Mr. Armstrong was in the second group of astronauts ever selected by NASA, following the original Mercury Seven.
Orbital flight was still rudimentary and his astronaut class would be involved in the first U.S. spacewalk, the first long-duration missions, the first rendezvous between two spacecraft.
His first flight marked the first ever docking in space.
On March 16, 1966, Mr. Armstrong and crew mate David Scott lifted-off aboard the Gemini 8 capsule.
Once in orbit, they would latch onto the ATDA, a modified rocket stage that had been previously launched. A spacewalk would be performed.
However, within minutes of the docking, the combined Gemini-ATDA structure started to spin out of control. The astronauts pulled the Gemini away, but this only made their capsule tumble even faster.
"Pretty soon, they were doing a 360 every second. Their vision was getting blurred and they were worried that pieces of Gemini were going to start flying off," the late astronaut Deke Slayton recalled in his autobiography.
The two astronauts managed to stop the motion but the mission had to be aborted after little more than 10 hours in orbit. They made an emergency splashdown in the Pacific, waiting two hours before a ship could pick them up.
The failure was later tracked to an electrical short in the control systems.
Four more Gemini missions would be flown, developing techniques that would be used to fly to the moon. Mr. Armstrong meanwhile was reassigned to the Apollo program.
At the time, Mr. Slayton, who was chief of the astronauts' office, had developed a system where each crew of astronauts would act as back-ups on a mission, then two flights later would get their turn at being a mission's prime crew.
Initially, Mr., Armstrong was on the backup crew for what would have been on the Apollo 9 mission, meaning he would have eventually flown on Apollo 12, the second mission to land on the moon.
Under that scenario, rather than the laconic Mr. Armstrong, the first man on the moon would have been the backup commander for Apollo 8, an extroverted, wise-cracking Navy pilot named Pete Conrad.
In late 1967 and early 1968, Mr. Armstrong and Captain Conrad trained to land on the moon by flying the LLRV, a skittish flying contraption with a jet engine pointing downward, which hovered like a helicopter and simulated the lunar landing.
Again, Mr. Armstrong had a close brush with death. In May, on his 21st LLRV flight, a mechanical problem made the craft suddenly pitch downward. He ejected just seconds before it crashed.
However, fortune smiled on him a few months later. Hardware problems were threatening to delay the launch of what would have been the Apollo 8 flight. NASA officials decided to flip the Apollo 8 and Apollo 9 missions.
As a result, Mr. Armstrong went to become backup commander for Apollo 8 – and, as luck would have it, the first man to walk on the moon.