But designing a blimp to work at 300 degrees below zero is no piece of cake. The tricky part is coming up with a material for the blimp's envelope that will be strong enough to take a hard knock if the blimp bumps into a rock on Titan's surface. Several types of plastics seem promising, according to tests at JPL, but the researchers are still trying to come up with a glue that will seal the pieces together, including the blimp's interior bladder, which will be filled with helium to give it the necessary lift.
"Glues don't work at that temperature," Jones says. Again, several products look interesting, but require further testing, Jones says.
The idea is to build a fairly compact blimp, say about 30 feet in length, that could serve as an instrument platform for everything from high altitude observations to close-up photographs. Once they get to Titan, Jones says, it should be pretty smooth sailing because the atmosphere has very little wind.
There's so little heat from the sun that there isn't a dynamic weather system like we have on Earth. Titan is so far from the sun that sunshine reaching its cloud-tops is about 100 times less than we receive here on Earth. And about 90 percent of that is absorbed by the upper atmosphere, so about a thousand times less sunlight actually reaches the surface of the moon.
That's unfortunate, in a way, because Titan's atmosphere is so rich in organic elements that it is ripe for life, just as the Earth was so long ago. What's really lacking is heat that most scientists believe is necessary for the spark of life.
Seeking Heat, Seeking Life?
So the blimp, if indeed this works out, will probably carry an infrared camera which could detect any heat on the surface of Titan. Many scientists think heat may indeed be generated by geophysical processes on the large moon.
"That would be tremendously interesting to scientists because you have all the ingredients for life there," Jones says. So if the infrared camera detects a hot spot, the blimp could zoom down for a closer look.
"By golly," Jones says, "we might stumble onto some life.
"That would be very exciting."
But of course, as he notes, the ultimate all terrain vehicle is still a long ways from reality. If the Cassini mission shows that it is possible for instruments to function in the dense atmosphere of Titan, then the Aerover Blimp, as JPL officials call it, might be just the ticket for a follow-up mission.
That could come within a decade.
And what an interesting footnote to aviation history that would be. The first human flight of any kind is generally credited to the Montgolfier brothers of France, who built a hot air balloon and flew for five miles over Paris in 1783. Maybe similar technology will allow us to explore a very forbidding world.
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.