Mission controllers at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. are ramping up for an era of unprecedented space exploration. The Lab is poised to launch and direct a fleet of space probes that will, among many other things, crash into the heart of a distant comet, snatch particles of the solar wind, rove across Mars to search for evidence of liquid water, and descend through the atmosphere of Saturn’s moon Titan to explore what reminds many scientists of an early Earth.