The Apollo Program
Armstrong's first tour of service to the Apollo program came as the commander of the back-up crew of the Apollo 8 mission, though he had been originally scheduled to back-up the Apollo 9 mission. (Had he remained as the Apollo 9 back-up commander he would have been slated to Command Apollo 12, not Apollo 11.)
Initially, it was planned that Buzz Aldrin, the Lunar Module Pilot would be the first to set foot on the Moon. However, it was determined that because of the positions of the astronauts in the module, it would require Aldrin to physically crawl over Armstrong to reach the hatch. As such, it was decided that it would be easier for Armstrong to exit the module first upon landing.
Apollo 11 touched down on the surface of the Moon on July 20, 1969, at which point Armstrong declared, "Houston, Tranquility Base here. The Eagle has landed." A hugh sigh of relief was said to have been breathed throughout mission control, as it was thought that Armstrong had merely seconds of fuel remaining before the thrusters cut and the lander plummeted to the surface. Armstrong and Aldrin exchanged congratulations before quickly preparing the lander to launch off the surface in case of an emergency.
Man's Greatest Achievement
On July 20, 1969, Armstrong made his way down the ladder from the Lunar Lander and, upon reaching the bottom declared "I'm going to step off the LEM now." As his left boot made contact with the surface he then spoke the words that defined a generation, "That's one small step for man, one giant leap for mankind."
Interestingly, he meant to say "one small step for a man," referring to himself. Otherwise the phrase is actually contrary, since as stated man would imply mankind. Armstrong later was reported as saying that he hoped future quotations would include the "a" parenthetically. However, the phrase is still usually conveyed as he originally spoke it.
About 15 minutes after exiting the module, Aldrin joined him on the surface and they set to investigating the environment on the lunar surface. They also planted the American flag on the surface. But because of a malfunction of the bottom extender of the flag, the flag appeared to be waving. This, of course, would be impossible since there is no air on the Moon. It was supposed to be repaired on a later mission, but because the astronauts liked the way it looked, it was kept in the same condition.
The final task carried out by Armstrong was to leave behind a package of memorial items in remembrance of deceased Soviet cosmonauts Yuri Gagarin and Vladimir Komarov, and Apollo 1 astronauts Gus Grissom, Ed White and Roger Chaffee. All told, Armstrong and Aldrin spent 2.5 hours on the lunar surface. Each of the subsequent landings allowed for more and more time on the surface, culminating in 21 hours of extra-vehicular time performed by the Apollo 17 astronauts.
The astronauts then returned to Earth, splashing down in the Pacific Ocean on July 24, 1969. Armstrong was awarded the Presidential Medal of Freedom, the highest honor bestowed upon civilians, as well as a host of other medals from NASA and other countries.
Life After Space
After a short stint as an administrator with NASA and the Defense Advanced Research Projects Agency (DARPA), Armstrong accepted a teaching position at the University of Cincinnati with the department of Aerospace Engineering. He held this appointment until 1979. Armstrong also served on two investigation panels. The first was after the Apollo 13 incident, while the second came after the Challenger explosion.
Armstrong now lives a life outside the public eye. He stopped signing autographs more than a decade ago when he came to know that people were selling items baring his signature for thousands of dollars. There have also been issues with individuals selling forgeries. Armstrong will occasionally make public comments when asked about NASA and current policy. The most recent statement, in early 2010, was in staunch criticism of the President's plan to cancel the Constellation program.