September 15 beginning at 7 a.m. EDT. It takes 83 minutes for a signal from the spacecraft to reach Earth.
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“It’s a bittersweet, but fond, farewell to a mission that leaves behind an incredible wealth of discoveries that have changed our view of Saturn and our solar system, and will continue to shape future missions and research”, said a statement from Michael Watkins, director of NASA’s Jet Propulsion Laboratory in Pasadena, California, which oversees the Cassini mission. This plan was the Grand Finale, 22 ever-more-daring orbits skimming Saturn’s atmosphere and darting between the rings until finally, inevitably, steepening Cassini’s near-misses into a final plunge directly into Saturn.
After a 20-year voyage, NASA’s Cassini spacecraft is poised to dive into Saturn this week careening through the atmosphere and burning up like a meteor in the sky over the ringed planet. “I hope you’re all as deeply proud fo this awesome accomplishment. Congratulations to you all”, said project manager Earl Maize as the mission ended.
As Cassini lost signals, flight controllers wearing purple shirts stood and hugged each other and shook hands.
On Wednesday, NASA’s planetary science division director Jim Green spoke about Enceladus, a small, icy moon, spewing organic material that likely originates from a subsurface ocean. Their farewells already said, team members planned to raise their glasses in a final salute. They were born perhaps from the rubble of comets or disintegrated moons.
Before its end, Cassini took a variety of samples in an effort to gain a better understanding of the planet’s composition.
Cassini included multiple instrument packages, including a composite infrared spectrometer, narrow and wide-angle digital cameras, and the ability to observe Saturn and its moons in both ultraviolet and infrared. “It would be really nice if we did”, Molly Bittner, a systems engineer at JPL who has worked on Cassini for the past four years, tells NPR.
The probe was running low on fuel, and the 13-year tour of the Saturn system mission must end.
Radio contact with the 22ft long nuclear-powered probe was lost at at 12.56 pm United Kingdom time as Cassini tumbled to its doom 930 miles above Saturn’s cloud tops. Twenty-two times, Cassini entered the gap and came out again. (The planet is 930 million miles away.) While it’s very unlikely telescopes on Earth will record the event, NASA TV is broadcasting live from the Cassini control room during that time. The Huygens probe landed on a dark patch of land which it found to be made up of ice grains and littered with rounded hydrocarbon-coated water ice, indicating that it was a dried riverbed.
NASA and its global partners decided the best option was to deliberately send the spacecraft hurtling into the planet, rather than risking a collision with one of Saturn’s moons.
In all, Cassini collected more than 453,000 images and traveled 4.9 billion miles. The final price tag was $3.9 billion.
There were lighthearted touches as well.
As Cassini hurtles on towards its death, the program head at NASA – Curt Niebur – is philosophical about the probe’s final fate.
“That is completely surprising because before we went to Titan, we had never seen under the atmosphere”. Proposals are under consideration by NASA, but there’s nothing official yet.
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With Cassini running on empty and no gas station for about a billion miles, NASA made a decision to go out Thelma & Louise-style.
