The Deferred Dreams of Mars

In August, NASA used a series of precise and daring maneuvers to put a one-ton robotic rover named Curiosity on Mars. A capsule containing the rover parachuted through the Martian atmosphere and then unfurled a "sky crane" that lowered Curiosity safely into place. It was a thrilling moment: here were people communicating with a large and sophisticated piece of equipment 150 million miles away as it began to carry out experiments that should enhance our understanding of whether the planet has or has ever had life. So when I visited NASA's Johnson Space Center in Houston a few days later, I expected to find people still basking in the afterglow. To be sure, the Houston center, where astronauts get directions from Mission Control, didn't play the leading role in Curiosity. That project was centered at the Jet Propulsion Laboratory, which Caltech manages for NASA in Pasadena. Nonetheless, the landing had been a remarkable event for the entire U.S. space program. And yet I found that Mars wasn't an entirely happy subject in Houston—especially among people who believe that humans, not only robots, should be exploring there.