As a spacecraft, Dragonfly would be an oddity: It would have propellers, like a helicopter — “a nuclear quadcopter to look for life on Saturn’s moon, Titan,” Peter Bedini, a program manager at Johns Hopkins Applied Physics Laboratory, said in a recent talk.
“Seems kind of straightforward. Or arbitrary.”
Proponents of this concept say a quadcopter would be an ideal way to explore Titan, Saturn’s largest moon. The air is thick there, thicker than on Earth. The landscape is varied, interspersed with obstacles — rivers, lakes and seas of liquid methane — that could prove inaccessible for a rover.
The booming popularity of flying drones in recent years makes the technology potentially feasible for interplanetary exploration, too.
“Ten years ago, they were kind of rare things that only enthusiasts experimented with,” said Elizabeth Turtle, a planetary scientist at the Johns Hopkins laboratory, who would serve as the mission’s principal investigator. “Now everyone can have a drone.”
In the past, scientists have suggested exploring the moon with balloons and airplanes. But Titan’s geology — sand dunes, eroded gullies — is more interesting than what is in the air. Dragonfly would fly from place to place, but would spend most of its time performing experiments on the ground.
“In terms of what we’re looking for on Saturn, it really hit exactly the sweet spot,” Dr. Turtle said.
A second Titan proposal, Oceanus, is led by Christophe Sotin, the chief scientist for solar system exploration at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., which was Cassini’s home base.
The Oceanus spacecraft would study the moon from orbit, potentially identifying habitable regions for life.
Jonathan I. Lunine, a planetary scientist at Cornell University, was a member of the science team managing the Huygens probe, which traveled to Saturn with Cassini and landed on Titan.
He would be the principal investigator on a proposed mission to revisit Enceladus, a small moon just 313 miles wide. The discovery of geysers shooting from its south pole was a stunning surprise, and now the moon is considered a prime place for look for life.
“Cassini gave us a big pointer to where we need to go to look for life,” Dr. Lunine said. “If we are interested in…