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NASA's Cassini-Huygens will finish Saturn mission tomorrow with destructive dive

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The earth as seen from Saturn

With the end of Cassini, there is no other mission now operating or under development to visit Saturn or its moons.

Live data will be streamed for the first time from Cassini via Canberra to the world in the early evening before the bus-sized spacecraft uses its last drops of fuel to manoeuvre directly into Saturn's atmosphere and begins its expected disintegration.

"Because of the importance of Enceladus that Cassini has shown us, and of Titan, we had to make decisions on how to dispose of the spacecraft", said Jim Green, NASA's director of planetary science. "It will radiate across the solar system for almost an hour and a half after Cassini itself has gone", Earl Maize, Cassini project manager at NASA's Jet Propulsion Laboratory, said in a statement. They do not want any earthly organisms that may be on Cassini to contaminate a moon that may have life. Huygens landed on Titan, one of Saturn's many moons, while Cassini continued a 13-year orbit mission around Saturn.

Cassini was the first spacecraft to visit Saturn since the flyby of the planet by Voyager 2 in 1981.

Cassini was launched in 1997 and arrived at Saturn in 2004. She said that such findings help scientists better understand how life formed in our solar system, how the solar system developed, and, by implication, how other solar systems may be assembled.

Larry Esposito is a professor of astrophysical and planetary sciences at CU. Built at Jet Propulsion Laboratory under the leadership of Robert Brown, operations for VIMS moved to the UA when Brown assumed a position as professor at LPL. During its time, Cassini discovered six new moons as well as new rings.

We saw the tiny icy moon of Enceladus reveal its 101 geysers which shoot hundreds of pounds of water ice and molecular hydrogen into space from a subsurface ocean.

Still, he expressed confidence that the mission would ride through its final hours without a problem, thanks to the Cassini team's preparation.

"Just as I was inspired as a kid by watching Apollo 11 land on the Moon, today's school kids have the opportunity to witness the spectacular finale of Cassini zooming through Saturn's rings". NASA's ever-shrinking budget could mean these questions get put on hold-especially since Cassini is proof that NASA should go big or go home.

A high-point of the mission came in January 2005 when Huygens dropped through the dense hydrocarbon atmosphere of Saturn's largest moon Titan, and touched down on a pebble-strewn surface with the consistency of wet sand. The acting Ace would then send them on to the spacecraft. Because of that, engineers chose to let the spaceship burn up in the planet's atmosphere rather than crashing into one of the moons, possibly contaminating it. Enceladus plows along the orbit of the E Ring, Saturn's second-from-outermost ring, which reaches extremely far out into space, brushing up against the orbit of Titan.

"We saw that these plumes are quite large and extensive", he recalls. Instead, Cassini will be configured to run only those instruments that can sense the planet's near-space environment, such as its magnetic field, or that can sample the chemical composition of its gases.

The Cassini-Huygens spacecraft will make its plunge into Saturn's atmosphere on September 15, after 20 years in space.

"We do see the water, but we see other constituents as well", he said.

Cassini's imaging camera will take a last look at the Saturn system on the day before the plunge and will be off during this final descent.

"The spacecraft will be transmitting data until the very end, and we'll be there when it stops", McEwen says. In this case, success will be indicated by the probe going permanently silent. On the way it made fly-bys of Venus, the Earth, and Jupiter to receive gravitational "kicks" that boosted its speed to more than 42,500mph.

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