It was September 12, 1962, when Pres. John F. Kennedy delivered a speech at Rice University before nearly 50,000 people. By that time, America had launched but four men into space--the suborbital flights of Alan Shepard and Gus Grissom and the nearly identical three-orbit journeys of John Glenn and Scott Carpenter. Buoyed by the success of those missions and cognizant of the danger that lay ahead, the president rearticulated his vision and reissued his challenge to reach the moon before 1970. "We choose to go to the moon, in this decade and do the other things, not because they are easy, but because they are hard. Because that goal will serve to organize and measure the best of our energies and skills." The assassination of President Kennedy, in the words of flight director Gene Kranz, turned his vision into a "quest to do it and do it in the time frame he allotted." On July 20, 1969, Neil Armstrong stepped off the ladder of the lunar module known as Eagle, taking "one small step for man, one giant leap for mankind."