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Technology & Entrepreneurship

NASA's Cassini Prepares For Third Dive

Courtesy of NASA
The rings of Saturn

Tuesday Morning, a little after 1 a.m., NASA's Cassini mission begins its third dive between Saturn and the planet's rings. As the long-operating probe continues its so-called Grand Finale, San Antonio scientists will be poring over the data.

Cassini launched in 1997, became the first craft to orbit Saturn in 2004 and completed its primary mission in 2008. After two mission extensions, Cassini will now dive weekly between Saturn and its rings 19 more times--for a total of 22 -- before crashing into the planet's surface September 15.

Southwest Research Institute scientist Hunter Waite runs science on Cassini's Ion and Neutral Mass Spectrometer, which can determine the molecular composition of the atmosphere, or as Waite puts it, "different than the remote sensing, it'll just like sniff the the atmosphere."

Starting on the project in 1992, Waite has learned to expect the unexpected with these celestial bodies. For instance, Saturn's moon Titan.  They expected to find just a few compounds in its dense haze, but instead he says they found the largest organic compound factory in the solar system. 

"It produces coal gas and oil reserves at well over 100 times that you find on the Earth," Waite says, explaining Titan's unusual cycle.

"Well [the compounds] are created in the atmosphere; and it falls out and precipitates on the planet, so you get these organic dunes. You get lakes of methane and ethane."

Credit NASA/JPL-Caltech/Space Science Institute
Titan, March 6, 2017

Titan's climate is around -285 degrees Fahrenheit, so, like water on Earth, methane can exist as a liquid, solid or gas. Something like oil is frozen and exists as giant dunes across Titan's equatorial region.

The first Saturn dive they used the dish as a shield, since it was all about surviving the trip.

"At roughly 35 kilometers per second that we're traveling. it only takes something smaller than a BB to take it out," says Waite. 

Encountering less material between Saturn and its rings now means they can move on with science dives. Each dive will prioritize specific instruments.

The Ion and Neutral Mass Spectrometer will get the limelight on dive 9, so we may find out what Saturn smells like the week of June 13.