Science
Related: About this forumFascinating collection of photos taken during Cassini's final orbits around Saturn (Video)
A video posted this past June on the channel Astrum is an utterly fascinating collection of shots taken by Cassini as well as graphics of its orbital path (edit; As well as animations, which add to the story). An example of some of the really interesting stuff is that a Shepherd Moon - Daphnis - is actually captured within the plane of the rings and disrupts the rings on either side of it, like a boat makes a wake. I had absolutely no idea! Well, it isnt a surprise that I had no idea, as I am not quite the student of our Solar System that I would like to think I am!!
I dont think I have ever put up a post in this group, so forgive me if this has been posted before. I searched for a post containing this video but couldnt find one.
Anyway, take ten minutes and be amazed;
Edit to add that this video does have an advertisement for a VPN at the end.
brer cat
(24,646 posts)That was fascinating.
A HERETIC I AM
(24,382 posts)yonder
(9,685 posts)Interesting that in the final plunge they chose to send more data rather than photos to maximize bandwidth value. Scientists doing what scientists do, thankfully.
A HERETIC I AM
(24,382 posts)The trade off on how to best use the bandwidth, yes?
It is simply beyond remarkable what these talented men and women are capable of.
Orbital calculations that are essentially threading a needle from a million miles away, so to speak.
I once read something to the effect that the accuracy of the math needed to insert a Mars bound spacecraft into Martian orbit was the equivalent of shooting a basket located in the Staples Center in LA from the top of the Empire State Building and hitting nothing but net.
This sort of thing is another level entirely.
yonder
(9,685 posts)"You're staking out some curb, not building a Steinway. Get a move on!"
OR
"You're calculating your traverse closure, not a trajectory to Mars. Hustle it up!"
My brother and I have put a Few things together in the past and the well, we aint building a piano comment has come up more than once!
Yes indeed.
It would seem to me that the variance of the calculation down to the 4th decimal (or more, perhaps) means either getting it through the rings of Saturn or sending the craft completely elsewhere!
yonder
(9,685 posts)I'm not sure I could still work one - add or multiply would be about it, if anything.
It's no wonder why we see those clips of scientists and engineers in a control room jumping up for joy when a certain aspect of a mission has been confirmed a success. A wing and a prayer comes to mind for me but they would probably say: "nah, all science."
A HERETIC I AM
(24,382 posts)I put up this thread originally back in 2009, on the 40th anniversary of the Apollo 11 landing, and then again last year. I said basically the same thing;
https://www.democraticunderground.com/100212285887
To think that the most commonly used calculation tool in those days was a slide rule and that the entire program, down to the smallest rivet, was done before the days of CAD/CAM assisted tooling and machining, is just mind blowing
Im not sure I could even add or multiply with a slide rule anymore!
My husband designed some parts for the cabins in the Apollo missions and he did it with a slide rule (hes almost 10 years older). I never used one at a job because calculators became so ubiquitous.
The 1st time I took college trig/pre-calc in 69 they had a rule that you could NOT bring a calculator to class. I had to quit in my sophomore year and didnt get back for over 5 years. I took trig again, same college, as a refresher but the rules had changed such that a calculator was REQUIRED!?!
Eventually could afford an HP 15C in the mid-80s. Still have that baby and it still works like a charm.
yonder
(9,685 posts)I have an 11c, two 15c's, a couple of 32s II's, a 33s I think, a 48gx with surveying cards, a 45s and used to have a brand new 42s which I traded for one of the 15c's thirty years ago. That was a mistake but now have a 42 emulator on my phone which has accepted an old star/sun shot program that works just fine. Now that I'm semi-retired, most of them just collect dust in the drawer.
Of all of them, the beater 15c was the work horse. It went into the field with me every day, had half a dozen simple surveying programs in it (what, some 250-300 program lines of memory total??), you could bang it around and was easily worth its weight in gold. Those were days when almost all calculations were done in the field with very little office support other than a plat or a set of plans and maybe some record coordinates. And the batteries! I'm willing to bet you can't remember the last time you replaced those button batteries in yours, myccrider. Am I right? They last forever, like 5-10 years of everyday, hard use, probably 12 or more unused.
And RPN. Enough said other than once you get onto it, it's tough to go back. Hell, it's downright painful when forced to use a common cruncher.
So I'll hop off the HP soapbox and apologize to the OP for busting the thread. I'll just maintain the blame is shared for you bringing up your own HP15c, which is a much, much better tool than a slide rule and a moldering book of sine tables.
myccrider
(484 posts)Yep, havent changed the battery for over 10 years. I was just thinking the other day that I should get a spare, just in case.
Jeebo
(2,034 posts)They posted lots of pictures from Cassini on the Astronomy Picture of the Day site, and they were all just simply breathtaking. Thank you for posting this.
-- Ron
A HERETIC I AM
(24,382 posts)I searched Cassini on DU and found numerous threads over the years, so there is clearly interest.
Im glad you enjoyed the video