Jupiter’s moon Europa is a worthy target for exploration, so don’t get me wrong. It’s good news that NASA and the European Space Agency are going forward with plans for a dual-spacecraft mission to Europa, Ganymede and Jupiter's other moons in 2020. It just means we won’t see balloons flying over Saturn’s moon Titan any time soon. And that’s a pity.
Two teams of planetary scientists and engineers spent the last year hammering out detailed proposals for the next multibillion-dollar mission to the outer solar system. The two concepts went mano a mano to compete for one near-term funding opportunity, with the Europa Jupiter System Mission emerging the winner after being judged “more technically ready.”
That relegates the Titan Saturn System Mission to some vague and distant future.
Fair enough. But Titan is one of only four places in the solar system with an atmosphere, which means we could send balloons, airplanes, or some other flying machine to roam over the surface taking pictures, sniffing the air, and covering far more territory than a rover could. Titan balloons have been studied by engineers on both sides of the Atlantic, but it was a French Montgolfière design that was included in the ESA-NASA Titan proposal. The balloon measures 35 feet across and would fly at an altitude of six miles for six months or more.
Future missions could go beyond these floaters to include Titan airplanes, which have been imagined in various sizes. My favorite is the Titan Bumblebee, a two-and-a-half-pound UAV that would fly over the moon's surface for several hours after being released from a lander. I don’t even care if that one works, I like the name so much.
Ah well, maybe someday.