NASA Spacecraft Dives Between Saturn and Its Rings | Hacker News Reader

NASA Spacecraft Dives Between Saturn and Its Rings

nasa.gov

134 pointsdanparsonson16 comments

As someone working on what amounts to fairly trivial applications in the enterprise, it's amazing to see engineering efforts like this take place over nearly 20 years of in-flight time.

It's amazing to me how normalized these accomplishments has become. Humanity didn't master rocketry until the mid-20th century, and now we regularly have robotic vehicles flying around other planets (and sending photos to us).

Perhaps it's an example of how humans naturally notice only change. This is just more of the same, I suppose.

And we also hear how incompetent and inefficient NASA and the whole U.S. government are. They certainly could improve but they also just flew a craft around Saturn, for 12 years. What was it that you were working on again?

The mission duration will end up being about a month shy of 20 years; even more impressive:)

Humanity is very vague, it was the Nazi Germany (wernher von braun) who mastered the rocketry, without them the space program would have been years if not decades behind. btw i don't get the amazement when 28 years ago we had Voyager's 2 flyby photos of Neptune.

You also have to compare NASA's incredible success rate to others in their field. In 2013, China's Yutu moon rover broke down in less than a month. In 2014, the ESA's Philae lander failed to launch its harpoons and fire the thruster necessary to attach the probe to the comet's surface, and ultimately bounced into a dark crater. In 2011, Russia's ambitious Phobos-Grunt mission to return a sample of Martian soil never got beyond low Earth orbit because of a rocket misfire.

I'm not saying other space agencies aren't doing impressive and amazing work. (Both Yutu and Philae were able to keep functioning and achieve at least some of their mission objectives.) I'm just saying space exploration is Really Hard. And NASA and its partners keep succeeding, even when they try crazy new things, like landing the SUV-sized Curiosity rover with the Rube Goldberg-like "Sky Crane maneuver", or sending a nearly two-decade-old spacecraft through the narrow gap between Saturn's rings and the planet's atmosphere.

We take their successes for granted, like this stuff is easy, but it's not, even for teams of well-funded geniuses. Worth taking a second to appreciate the engineering achievement as well as the science.

Cassini has been the most incredible mission… so many fascinating discoveries and wonderful imagery. We really need to do more (far more) missions like this.

I've really been enjoying it also, we're so far past the expected lifespan of this mission every new picture and reading is a gift; well done to all involved! We get things right sometimes! The software onboard remains a bit of a black box though; I'd really love to know the software architecture of these things...

I'm not too up on the capabilities of Cassini, but considering how long it's been in action would I be right to guess we're not going to get any kind of 'steaming video' of the final dive? Some pics will get picked up before it meets its end in saturn's atmosphere would be great anyway!

I'm hoping we can find enough out with Cassini's swan song to get interest up enough to fund lander missions to Europa and Titan (if we can work out how to totally sterilize things, right?) but I don't think anything is on the cards currently..

Wishlist stuff: I really love the pics; but having HD video streams from twhat he next gen of craft will be would be so amazing, I really hope we get there someday...

I'm very much looking forwards to the James Webb scope when it gets launched too!

Edit: You can see some pics here [0] and one of my favourites [1].

[0] : https://saturn.jpl.nasa.gov/galleries/raw-images/ [1] : https://saturnraw.jpl.nasa.gov/multimedia/images/raw/casJPGF...

Those raw images are mind blowing. Kerbal Space Program isn't too far off. :)

https://saturnraw.jpl.nasa.gov/multimedia/images/raw/casJPGF...

Just to geek out even more-- I really liked this one of enceladus too [0] ... I wish I knew an astronomer who could explain what that 'shooting star' looking thing is in that pic..

Do you have any ideas?

I'd expect every bit of light to be streaked if it was a long exposure, so it has to be something moving? Massive "I'm totally uneducated on all this stuff" disclaimer -- but if this pic was taken from inside saturn's atmosphere; did it capture a 'shooting star' ??

[0]: https://saturnraw.jpl.nasa.gov/multimedia/images/raw/casJPGF...

It's probably a cosmic ray, which overloads the CCD detector in a streak-like pattern as it flies through the focal plane. All uncorrected deep space imagery has them.

Aha; thanks! I'm pretty sure I like the effect even more because of your explanation though!

Both Europa (around Jupiter) and Enceladus (around Saturn) have gas plumes and indications of liquid oceans. The situation is pretty well summarized here: https://www.nasa.gov/press-release/nasa-missions-provide-new...

There is a mission in formulation for Europa (https://www.nasa.gov/feature/jpl/nasa-mission-named-europa-c...) and an Enceladus concept called ELF.

I be right to guess we're not going to get any kind of 'steaming video' of the final dive?

We aren't. We aren't likely to get streaming video from an interplanetary probe anytime soon. The Japanese lunar orbiter SELENE/Kaguya had HD video cameras and those didn't transmit in real-time either. And the moon is practically next door.

The photo that you link to shows the rings convex, as if it had been shot from outside the rings. How is that perspective taken from the dive?

Obviously Cassini is in orbit around Saturn, so even before and after the dive the rings should have appeared concave.

The FAQ[0] about the images has some interesting things in it:

> Why are there images of different sizes?

> The Cassini cameras are 1-megapixel cameras. A normal image is 1024 x 1024 pixels. Using a technique called "summation" the cameras have the ability to combine pixels together to get smaller but less noisy images. This results in smaller images that take a lot less time to readout out and take up less data volume. Summation is very useful if a scientist needs to conserve both. In the 2 x 2 mode, the camera takes a 2 x 2 pixel square and averages those values into a single pixel. Images in this mode will be 512 x 512 pixels. In the 4 x 4 mode, the camera takes a 4 x 4 pixel square and makes that a single pixel. Images in this mode are 256 x 256 in size.

[0] https://saturn.jpl.nasa.gov/faq/#raw_images

Amazing

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