Early on the morning of April 12, 1981, two astronauts sat strapped into their seats on the flight deck of Columbia, a radically new spacecraft known as the space shuttle. John Young, the commander, had already flown in space four times, including a walk on the moon in 1972. Bob Crippen, the pilot, was a Navy test pilot who would go on to command three future shuttle missions. But nothing either man had done or would do was quite like this.