https://www.jpl.nasa.gov/news/news.php?release=2017-231&rn=news.xml&rst=6935
In its final week, Cassini will pass several milestones en route to its science-rich Saturn plunge. (Times below are predicted and may change slightly; see https://go.nasa.gov/2wbaCBT for updated times.)
- Sept. 9 Cassini will make the last of 22 passes between Saturn itself and its rings -- closest approach is 1,044 miles (1,680 kilometers) above the clouds tops.
- Sept. 11 -- Cassini will make a distant flyby of Saturn's largest moon, Titan. Even though the spacecraft will be at 73,974 miles (119,049 kilometers) away, the gravitational influence of the moon will slow down the spacecraft slightly as it speeds past. A few days later, instead of passing through the outermost fringes of Saturn's atmosphere, Cassini will dive in too deep to survive the friction and heating.
- Sept. 14 -- Cassini's imaging cameras take their last look around the Saturn system, sending back pictures of moons Titan and Enceladus, the hexagon-shaped jet stream around the planet's north pole, and features in the rings.
- Sept. 14 (5:45 p.m. EDT / 2:45 p.m. PDT / 9:45 p.m. UTC) -- Cassini turns its antenna to point at Earth, begins a communications link that will continue until end of mission, and sends back its final images and other data collected along the way.
- Sept. 15 (4:37 a.m. EDT / 1:37 a.m. PDT / 8:37 a.m. UTC) -- The "final plunge" begins. The spacecraft starts a 5-minute roll to position INMS for optimal sampling of the atmosphere, transmitting data in near real time from now to end of mission.
- Sept. 15 (7:53 a.m. EDT / 4:53 a.m. PDT / 11:53 a.m. UTC) -- Cassini enters Saturn's atmosphere. Its thrusters fire at 10 percent of their capacity to maintain directional stability, enabling the spacecraft's high-gain antenna to remain pointed at Earth and allowing continued transmission of data.
- Sept. 15 (7:54 a.m. EDT / 4:54 a.m. PDT / 11:54 a.m. UTC) -- Cassini's thrusters are at 100 percent of capacity. Atmospheric forces overwhelm the thrusters' capacity to maintain control of the spacecraft's orientation, and the high-gain antenna loses its lock on Earth. At this moment, expected to occur about 940 miles (1,510 kilometers) above Saturn's cloud tops, communication from the spacecraft will cease, and Cassini's mission of exploration will have concluded. The spacecraft will break up like a meteor moments later.
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NASA's Cassini Spacecraft Ends Its Historic Exploration of Saturn
Telemetry received during the plunge indicates that, as expected, Cassini entered Saturn's atmosphere with its thrusters firing to maintain stability, as it sent back a unique final set of science observations. Loss of contact with the Cassini spacecraft occurred at 7:55 a.m. EDT (4:55 a.m. PDT), with the signal received by NASA's Deep Space Network antenna complex in Canberra, Australia.
[...] As planned, data from eight of Cassini's science instruments was beamed back to Earth. Mission scientists will examine the spacecraft's final observations in the coming weeks for new insights about Saturn, including hints about the planet's formation and evolution, and processes occurring in its atmosphere.
[...] Cassini launched in 1997 from Cape Canaveral Air Force Station in Florida and arrived at Saturn in 2004. NASA extended its mission twice – first for two years, and then for seven more. The second mission extension provided dozens of flybys of the planet's icy moons, using the spacecraft's remaining rocket propellant along the way. Cassini finished its tour of the Saturn system with its Grand Finale, capped by Friday's intentional plunge into the planet to ensure Saturn's moons – particularly Enceladus, with its subsurface ocean and signs of hydrothermal activity – remain pristine for future exploration.
Farewell, Cassini: a 20 year mission to Saturn comes to a life-protecting end
During the Jovian flyby, Cassini performed scientific observations of the planet, showing that Jupiter's cloud belts were areas of "net-rising atmospheric motion."
This observation contradicted previous hypotheses about Jupiter's dark and light belts and served to highlight differences in planetary weather systems.
During the flyby, Cassini was also able to study Jupiter's thin ring system, revealing that Jupiter's rings were composed of irregularly shaped particles that likely originated as ejecta from micrometeorite impacts with the moons Metis and Adrastea.
Cassini: The legend and legacy of one of NASA's most prolific missions
Previously:
(Score: 5, Funny) by bob_super on Thursday August 31 2017, @11:03PM (2 children)
* Sept 30: A giant ship emerges from the Saturn clouds, travels to Earth, stops over KSC. A door opens and a chunk of debris lands right by the front door. An alien using broken English specifies that they'd appreciate if we could keep our trash to ourselves, before giving us the four middle tentacles and flying back home.
(Score: 3, Funny) by Bot on Friday September 01 2017, @09:33AM
Sept 30: the top secret DIDGARS, distributed independent data gathering and reaction system, on its routine surveillance task picks up the story and considers it a threat, the analysis is summarized as: "You just called "trash" our brave data gatherer Cassini, prepare to die." and the automatically set course of action consists in zapping Saturn with HAARP generated gamma rays.
Account abandoned.
(Score: 2) by Murdoc on Friday September 01 2017, @06:05PM
I really shouldn't read this site first thing after I wake up. I read that as "stops over KFC", which made it harder to figure out, but since it was modded Funny, I tried going with it at first.
(Score: 2) by snufu on Friday September 01 2017, @09:53PM
nc