Most Overrated Space Achievement:

The fifteen-minute space flight of the astronaut Alan Shepard in May 1961. What happened: As part of Project Mercury, which would put America’s first astronauts into orbit, Shepard rode a Redstone rocket from Cape Canaveral and splashed down in the Atlantic, three hundred miles downrange. The hype: The Mercury astronauts were national heroes from the moment of their selection in April 1959. Life magazine breathlessly followed their every move, even running a lengthy cover story on their wives. Shepard’s flight featured live television coverage for a worshipful national audience; his idiomatic expression “Everything A-OK” briefly entered the language. Three weeks after that flight President Kennedy went before Congress and called on the nation to land a man on the moon. The overrating: A chimpanzee named Ham had made that same flight in January. The Redstone rocket was an obsolescent Army missile similar to the German V-2 of World War II. NASA’s deputy director had dismissed this project out of hand: “Tossing a man up in the air and letting him come back is about the same technical value as the circus stint of shooting a young lady from a cannon.”

Most Underrated Space Achievement:

Ranger 7 , an unmanned probe that struck the moon in August 1964, sending back TV images during its terminal dive. What happened: The Jet Propulsion Laboratory pursued Project Ranger with the goal of taking photos of the lunar surface at close quarters. The effort experienced a series of failures before finally gaining success, but it was quickly overshadowed by far more dramatic initiatives, focusing on astronauts in orbit and culminating a few years later in the manned moon landings. The significance: In achieving success, the Jet Propulsion Laboratory made itself over and became a different organization. Indeed, Ranger was the exercise that taught the lab how to build successful spacecraft. JPL went on to apply this newfound expertise to launch a new age of discovery, for during the following quarter-century its planetary probes visited every planet except Pluto. In the history of the world, nothing like this had happened since the great explorations of the sixteenth century.