In 1997, we aimed a rocket towards Saturn and sent a 13-foot-wide satellite off on a mission to explore the strange worlds in our own (relative) backyard.
This month, NASA announced plans to extend the Cassini space probe's Saturn sojourn until 2017—nine years longer than its original end date of 2008.
Why, exactly, does Cassini need those extra years? Most people probably know the mission best for the spectacular space photography it's produced.
But NASA is hoping to get more than just a gallery of beautiful images out of extending the orbiter's lifespan.
Armed with an array of 12 instruments—more than twice the number of science tools included on normal missions—Cassini is sort of a Swiss Army Knife in the sky.
As its mission continues, it will gather data that could help us pinpoint life-sustaining planets, or power our own with clean energy.
As it turns out, lift-off takes a lot longer than it looks on TV. The Cassini-Huygens mission, recently renamed Cassini Solstice Mission, has roots going all the way back to the early 1980s, when American and European agencies first recommended teaming up to send a probe to Saturn. In a lot of ways, it was a precursor of the International Space Station—proof that countries could overcome their differences and work together to further space exploration. It's the sort of thing that would have brought a tear to Gene Roddenberry's eye.
But publicly funded projects—particularly ones to the tune of $3.27 billion—cannot survive on space-kumbayas alone. To produce results worthy of the investment, Cassini was outfitted with sensors that allow it to collect information on everything from the space dust that hits it, to the infrared waves emanating off Saturn.
Those high-tech tools could actually collect more data than Cassini can send home, said Curt Niebur, NASA program scientist on the Cassini mission. That's because all the information--photos, sound and recorded data of all sorts--has to squeeze back to Earth through a very limited radio connection.
"The analogy today is a wifi signal. The further you get, the less data you can exchange," he said. "That's our biggest challenge. Most people don't realize that the spacecraft isn't taking data every second of every day, mostly because we just don't have the pipeline to send it."
But the information that does make it here is fascinating stuff. For instance, scientists had long known Titan, one of Saturn's many moons, was unusual, but, thanks to Cassini, we now know that it's more like Earth than anyone ever suspected. Despite an average temperature of -200°C, Titan has lakes, rivers and storms—they're just made of liquid methane, instead of water. There's also an extreme sort of weather cycle that evaporates lakes and moves them from the North Pole to the South along with changing seasons.
And Titan has another little secret that Cassini clued researchers in on--deep beneath the moon's surface, it's warm enough to harbor liquid water and create the kind of conditions enjoyed by bacteria. That's an important discovery, because it means we can start looking for life on planets we'd previously ruled out.
"We thought we'd have to look for a warm planet like Earth, but we're finding that in these cold, dark places there are processes occurring to generate heat under the ice, and life could quite possibly arise," Niebur said. "It's important because there are lots of gas giants out there in space. And they have lots of moons. And that increases the chances of us finding life dramatically, because those icy moons could be places where life exists after all."