Starship Asterisk*

APOD Robot wrote: Cassini Approaches Saturn

The Cassini spacecraft itself, low on fuel, is scheduled to end on Friday
when it will be directed to approach so close to Saturn that it falls in and melts. >>

https://www.washingtonpost.com/national/health-science/how-to-steer-a-spacecraft-into-saturn/2017/09/09/ce6a8d18-74af-11e7-8839-ec48ec4cae25_story.html?utm_term=.7e5206ed5db3 wrote:
How to steer a spacecraft into Saturn
By Joel Achenbach. Washington Post, September 9

<<Dreamed up when Ronald Reagan was president, and launched during the tenure of Bill Clinton, Cassini arrived at Saturn in the first term of George W. Bush. So it’s old, as space hardware goes. It has also run out of gas, basically, though precisely how much fuel is left is unknown. Program manager Earl Maize says,

“One of our lessons learned, and it’s a lesson learned by many missions, is to attach a gas gauge.”>>

https://kendalastronomer.wordpress.com/2009/09/08/checking-cassinis-fuel-gauge/ wrote:

Click to play embedded YouTube video.

Checking Cassini’s fuel gauge
Philip Stobbart Blog, Posted on 08/09/2009

<<The Cassini probe, presently still exploring the Saturn system, has two main propellant systems. The bipropellant system uses nitrogen tetroxide as the oxidiser and monomethylhydrazine as the fuel. The monopropellant system just uses hydrazine, but how do they tell how much fuel has been used, or how you even spell them? The two methods used are either to estimate the amount of fuel coming out and relate that to how much there once was or knowing the volume of the fuel tank and taking pressure and temperature readings, use the ideal gas laws (or some derivative thereof) – Pressure x Volume = number of molecule x Gas Constant x Temperature – to calculate what’s in there. Initially, these gave results that agreed to about 20%. This error was halved through work done on the fuel coming out method and a few further corrections drawn from performance tests have reduced the error further.

The result? Half the monopropellant remains as well as one tenth of the bipropellant, but that’s enough bipropellant to make it to 2017.>>

stephenv2 wrote:I'm in the midst of traveling to see the Grand FInale at JPL, so just quickly. This is repeat of the APOD from 2010 - the project is much farther along today.

There is much, much better version of that clip in 4K with better color here:

Click to play embedded YouTube video.

Stephen van Vuuren
Filmmaker

stephenv2 wrote:I'm in the midst of traveling to see the Grand FInale at JPL, so just quickly. This is repeat of the APOD from 2010 - the project is much farther along today.

There is much, much better version of that clip in 4K with better color here:

Click to play embedded YouTube video.

And the project is a full non-profit film for IMAX releasing in May 4th 2018 http://www.insaturnsrings.com which much of the credit due to attention from the original APOD back in March 2011 – I can never thank APOD enough for that.

The website has a 10 part series that details precisely how this clip and entire film has been made. http://insaturnsrings.com/when-will-it-be-done-pt-1/

Stephen van Vuuren
Filmmaker

https://en.wikipedia.org/wiki/Adagio_for_Strings wrote:
The Adagio for Strings has been performed on many public occasions, especially during times of mourning:

• Broadcast over the radio at the announcement of Franklin D. Roosevelt's death;
  Broadcast over the television at the announcement of John F. Kennedy's death
  Played at the funeral of Albert Einstein
  Played at the funeral of Princess Grace of Monaco
  Broadcast on BBC Radio several times after the announcement of the death of Princess Diana
  Performed in 2001 at the Royal Albert Hall to commemorate the victims of the September 11 attacks.

[b][color=#0000FF]Samuel Barber, photograph by Carl Van Vechten, 1944[/color][/b]

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<<Samuel Barber's Adagio for Strings began as the second movement of his String Quartet, Op. 11, composed in 1936 while he was spending a summer in Europe with his partner Gian Carlo Menotti, an Italian composer who was a fellow student at the Curtis Institute of Music. The inspiration came from Virgil's Georgics. In the quartet the Adagio follows a violently contrasting first movement (Molto allegro e appassionato) and is succeeded by music which opens with a brief reprise of the music from the first movement (marked Molto allegro (come prima) – Presto).

In January 1938 Barber sent an orchestrated version of the Adagio for Strings to Arturo Toscanini. The conductor returned the score without comment, which annoyed Barber. Toscanini then sent word through Menotti that he was planning to perform the piece and had returned it simply because he had already memorized it. It was reported that Toscanini did not look at the music again until the day before the premiere. On November 5, 1938, a selected audience was invited to Studio 8H in Rockefeller Center to watch Toscanini conduct the first performance, a radio broadcast which was also recorded. Initially, the critical reception was positive, as seen in the review by The New York Times's Olin Downes: "We have here honest music, by an honest musician, not striving for pretentious effect, not behaving as a writer would who, having a clear, short, popular word handy for his purpose, got the dictionary and fished out a long one.">>

stephenv2 wrote: ... the project is a full non-profit film for IMAX releasing in May 4th 2018 http://www.insaturnsrings.com

stephenv2 wrote:I'm in the midst of traveling to see the Grand FInale at JPL ...

Stephen van Vuuren
Filmmaker

MarkBour wrote: Give our deep appreciation and best wishes to the team at JPL for years, decades, of incomparable work

and to that lovable and amazing spacecraft, one last time.

Lasse H wrote:... and the music? Barber?

MIDI Life Crisis wrote:

Lasse H wrote:... and the music? Barber?

Yes, Barber's Adagio for Strings. I was disappointed that NASA didn't see fit to include a credit.

https://en.wikipedia.org/wiki/Adagio_for_Strings

Steve Dutch wrote:
When Pioneer 11 passed Saturn in 1979, some of the hot-dogger types at JPL thought it would be cool to dive through the Cassini Division. Cooler heads cautioned that there might be unseen material orbiting in the gap. Good call. It would have made for a spectacular end to the mission, but that wasn't the plan.

https://en.wikipedia.org/wiki/Rings_of_Saturn#Huygens_Gap wrote:

[b][color=#0000FF][size=125]The Cassini Division imaged from the Cassini spacecraft. The Huygens Gap lies at its right border; the Laplace Gap is towards the center. A number of other, narrower gaps are also present.[/size][/color][/b]

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<<The Cassini Division is a region 4,800 km in width between Saturn's A Ring and B Ring. It was discovered in 1675 by Giovanni Cassini at the Paris Observatory using a refracting telescope that had a 2.5-inch objective lens with a 20-foot-long focal length and a 90x magnification. From Earth it appears as a thin black gap in the rings. However, Voyager discovered that the gap is itself populated by ring material bearing much similarity to the C Ring. The division may appear bright in views of the unlit side of the rings, since the relatively low density of material allows more light to be transmitted through the thickness of the rings.

The inner edge of the Cassini Division is governed by a strong orbital resonance. Ring particles at this location orbit twice for every orbit of the moon Mimas. The resonance causes Mimas' pulls on these ring particles to accumulate, destabilizing their orbits and leading to a sharp cutoff in ring density. Many of the other gaps between ringlets within the Cassini Division, however, are unexplained.

The Huygens Gap is located at the inner edge of the Cassini Division. It contains the dense, eccentric Huygens Ringlet in the middle. This ringlet exhibits irregular azimuthal variations of geometrical width and optical depth, which may be caused by the nearby 2:1 resonance with Mimas and the influence of the eccentric outer edge of the B-ring. There is an additional narrow ringlet just outside the Huygens Ringlet.>>