Australia takes charge of guiding Cassini to its fiery death in Saturn’s skies

On Friday, at 8.31pm, the spacecraft Cassini will enter Saturn’s atmosphere, where turbulence will tear it apart.

The pieces will melt and disintegrate as they race across the gas giant’s skies like a shooting star.

Scientists in Australia are responsible for controlling the probe’s final descent, and hearing its final precious words.

Many of them have been listening to the satellite’s broadcasts for 20 years.

“We have been with Cassini since it opened its eyes on the universe,” says Glen Nagle, outreach lead at the CSIRO-managed Canberra Deep Space Communication Complex.

“And we’ll be with it until its last breath of data.”

…Cassini will try to gather as much scientific data as possible in its final moments and beam it back to Tidbinbilla via radio waves.

Instruments will try to measure the composition of Saturn’s atmosphere, its temperature and magnetic field.

The scientists in Tidbinbilla are aware they only get a single shot at this.

Things have been tenser than usual as they check and recheck systems for bugs and conduct dress rehearsals for Friday.

Inside Saturn’s atmosphere, Cassini won’t burn.

The planet’s -142 degree skies are far too cold for that. Instead, NASA says, it will be smashed into pieces by turbulence.

…After the signal goes dark, the scientists will keep their dishes pointed at Saturn for another hour and a half.

Just in case an old friend has any last words for us.

Full report:

http://www.smh.com.au/technology/sci-tech/australia-takes-charge-of-guiding-cassini-to-its-fiery-death-in-saturns-skies-20170913-gygem0.html

Any live feed? Like there was for Curiosity and Philae?

The space agency will begin live video coverage of Cassini’s death on Friday starting at 9pm AEST..

NASA can’t see the probe destroyed from 932 million miles away, since no other spacecraft exist at Saturn. However, it will show an animation of Cassini’s position. Hosts will cover the ins and outs of the final moments live from NASA’s Jet Propulsion Laboratory in California, where the mission is headquartered.

NASA expects the last signal — and confirmation of the probe’s destruction — to arrive at Earth around 9:56 p.m. AEST.

Read more at https://www.businessinsider.com/cassini-grand-finale-video-nasa-youtube-ustream-2017-9#Qs3yClFag8ImcASE.99

That’s a nicely specific time so test of assumptions and modelling. That’s what I will be watching.

I have seen a few NASA launches and events, it’s a great resource but I find the portal a bit tricky and you don’t get an indication of wether that feed you have chosen is doing nothing or frozen which gets tricky when they have long pauses.

I got 14/15.

Can you spot the facts about Cassini from the rubbish we just made up?

http://www.abc.net.au/news/2017-09-14/can-you-spot-the-facts-about-cassini-from-the-rubbish-we-made-up/8942902

5:17 am just finished watching a replay on NASA TV of the presentation a few days ago just after the first passage inside the rings. Some fascinating stuff there.

Science aims for the last few days include:
1. Sample the upper atmosphere, what in addition to hydrogen?
2. Catch a ring particle inside Cassini’s dust analyser. Fingers crossed.
3. Weigh the rings. How much mass is in the rings? We haven’t known.
4. How much dust is inside the innermost (D) ring? Startlingly little, Cassini can listen to dust hitting it’s antenna.
5. How fast does Saturn rotate? Nobody knows, all we can see is the cloud tops, so hoping to find out from magnetometer data in the last few days.

Cassini’s orbits. Technically known as “ball of yarn”

mollwollfumble said:

Good value for money, that one.

The 445 best pictures from Cassini, http://planetary.org/multimedia/space-images/saturn/?keywords=cassini

So long, Cassini, and thanks for all the info.

Assume you’re all watching NASA TV along with me.

Just started a replay of the presentation that I saw at 5 am this morning just after Cassini had its first dive between the rings and Saturn.

I am getting nothing from the control centre despite being on that feed? Is it just animations?

And the life briefing isn’t.

Coverage doesn’t start until 9. It’s just docs about Cassini until then.

How to watch NASA learn that Cassini has died

The space agency will begin live video coverage of Cassini’s death on Friday starting at 9pm AEST.

NASA can’t see the probe destroyed from 932 million miles away, since no other spacecraft exist at Saturn. However, it will show an animation of Cassini’s position. Hosts will cover the ins and outs of the final moments live from NASA’s Jet Propulsion Laboratory in California, where the mission is headquartered.

NASA expects the last signal — and confirmation of the probe’s destruction — to arrive at Earth around 9:56 p.m. AEST.

You can watch the NASA TV broadcast below at that time.

https://www.businessinsider.com.au/cassini-grand-finale-video-nasa-youtube-ustream-2017-9?r=US&IR=T#Qs3yClFag8ImcASE.99

Bubblecar said:

Coverage doesn’t start until 9. It’s just docs about Cassini until then.

How to watch NASA learn that Cassini has died

The space agency will begin live video coverage of Cassini’s death on Friday starting at 9pm AEST.

NASA can’t see the probe destroyed from 932 million miles away, since no other spacecraft exist at Saturn. However, it will show an animation of Cassini’s position. Hosts will cover the ins and outs of the final moments live from NASA’s Jet Propulsion Laboratory in California, where the mission is headquartered.

NASA expects the last signal — and confirmation of the probe’s destruction — to arrive at Earth around 9:56 p.m. AEST.

You can watch the NASA TV broadcast below at that time.

https://www.businessinsider.com.au/cassini-grand-finale-video-nasa-youtube-ustream-2017-9?r=US&IR=T#Qs3yClFag8ImcASE.99

Ahhh, cheers.

Live feed starting … now.
All right, when the introductory slide shuts off.

mollwollfumble said:

Live feed starting … now.
All right, when the introductory slide shuts off.

Now.

No photos on the final way in, because photos take too long to upload.

Magnetometer, spectrometer and other data coming back. I want to know if data from the last 22 orbits will tell us what the rings weigh and what the internal solid part of Saturn is rotating at.

Those JPL control rooms always look cosy at night.

Bubblecar said:

Those JPL control rooms always look cosy at night.

No live movie of it’s demise, the whole thing could be another elaborate scientific hoax.

Peak Warming Man said:

Bubblecar said:

Those JPL control rooms always look cosy at night.

No live movie of it’s demise, the whole thing could be another elaborate scientific hoax.

Not saying it…………………but when you look at some of those photos they/ve got photoshop written all over them…………….

Ion mass spectrometer is the key instrument – analyse the atmosphere of Saturn.
8 instruments still active at plunge into atmosphere.

The final photos are intended as a picture postcard of Saturn (and Titan and Enceladus)
The last photo has already arrived. It’s a picture of where it will plunge into the atmosphere.

They’re putting together a good show.

Listening

Signal loss coming up.

Cassini entering atmosphere at 75000 mph.

Bubblecar said:

Cassini entering atmosphere at 75000 mph.

So they say.

Signal dead.

Sad applause and hugs.

Can they plan a spacecraft that can fly in and out of the atmosphere?

Bubblecar said:

Sad applause and hugs.

S band signal hung on for about an extra six seconds after it was predicted to cut out. Good extra data.

The science summary from the final orbits and plunge is being presented at 7 to 9 am eastern USA time.
Is that a start an hour from now?

Tau.Neutrino said:

Can they plan a spacecraft that can fly in and out of the atmosphere?

Cassini has already done that two times in the past 22 orbits.

mollwollfumble said:

Bubblecar said:

Sad applause and hugs.

S band signal hung on for about an extra six seconds after it was predicted to cut out. Good extra data.

The science summary from the final orbits and plunge is being presented at 7 to 9 am eastern USA time.
Is that a start an hour from now?

It’s now about 8:10am in NYC.

mollwollfumble said:

Tau.Neutrino said:

Can they plan a spacecraft that can fly in and out of the atmosphere?

Cassini has already done that two times in the past 22 orbits.

I mean as deep as Cassini got to.

maybe in a near future a yearly competition to see which spacecraft can go the deepest and come out again

like robot competitions

Tau.Neutrino said:

Can they plan a spacecraft that can fly in and out of the atmosphere?

yes, called aerobraking.

Tau.Neutrino said:

mollwollfumble said:

Tau.Neutrino said:

Can they plan a spacecraft that can fly in and out of the atmosphere?

Cassini has already done that two times in the past 22 orbits.

I mean as deep as Cassini got to.

maybe in a near future a yearly competition to see which spacecraft can go the deepest and come out again

like robot competitions

I guess the problems are the bits hanging off the probe, they’d need thermal protection. unless you slowed enough to negate the need. then you would need extra fuel to boost the probe back up to a stable orbit. and to slow it in the first place.

And, of course, there is the 7 year wait for whatever it is to actually get there in the first place.

ChrispenEvan said:

Tau.Neutrino said:

mollwollfumble said:

Cassini has already done that two times in the past 22 orbits.

I mean as deep as Cassini got to.

maybe in a near future a yearly competition to see which spacecraft can go the deepest and come out again

like robot competitions

I guess the problems are the bits hanging off the probe, they’d need thermal protection. unless you slowed enough to negate the need. then you would need extra fuel to boost the probe back up to a stable orbit. and to slow it in the first place.

How far can a radio transmit signals go through Saturn atmosphere?

what if a bigger space probe was designed with multiple sensors on different layers

and in the middle of the probe are the antennas for transmission

so while the outer layers melt away transmission can still happen from the center of the probe

As Cassini ends, Canberra is still receiving signals from Voyager 2, right now.

Tau.Neutrino said:

ChrispenEvan said:

Tau.Neutrino said:

I mean as deep as Cassini got to.

maybe in a near future a yearly competition to see which spacecraft can go the deepest and come out again

like robot competitions

I guess the problems are the bits hanging off the probe, they’d need thermal protection. unless you slowed enough to negate the need. then you would need extra fuel to boost the probe back up to a stable orbit. and to slow it in the first place.

How far can a radio transmit signals go through Saturn atmosphere?

what if a bigger space probe was designed with multiple sensors on different layers

and in the middle of the probe are the antennas for transmission

so while the outer layers melt away transmission can still happen from the center of the probe

be better off using a probe like Huygens and a parachute.

Tau.Neutrino said:

ChrispenEvan said:

Tau.Neutrino said:

I mean as deep as Cassini got to.

maybe in a near future a yearly competition to see which spacecraft can go the deepest and come out again

like robot competitions

I guess the problems are the bits hanging off the probe, they’d need thermal protection. unless you slowed enough to negate the need. then you would need extra fuel to boost the probe back up to a stable orbit. and to slow it in the first place.

How far can a radio transmit signals go through Saturn atmosphere?

what if a bigger space probe was designed with multiple sensors on different layers

and in the middle of the probe are the antennas for transmission

so while the outer layers melt away transmission can still happen from the center of the probe

I’d to see how deep a spacecraft could go into the Sun’s atmosphere. I designed the shielding for that once. There really is no limit, it just gets harder and harder the deeper you go.

Am worried that Cassini could not detect trace elements carbon, oxygen, nitrogen in Saturn’s atmosphere because of contamination of reading by its own burning fuel.

According to reports, the final fuel level in Cassini was 1% +- 2%.

WOW, at the whole rocket science.

All this information we have got because of rocket scientists.

Huygens seeing into another world was a highlight.

mollwollfumble said:

As Cassini ends, Canberra is still receiving signals from Voyager 2, right now.

How long has it got?

mollwollfumble said:

As Cassini ends, Canberra is still receiving signals from Voyager 2, right now.

That’s kinda cool, that is.

Like a data send off.

mollwollfumble said:

Tau.Neutrino said:

ChrispenEvan said:

I guess the problems are the bits hanging off the probe, they’d need thermal protection. unless you slowed enough to negate the need. then you would need extra fuel to boost the probe back up to a stable orbit. and to slow it in the first place.

How far can a radio transmit signals go through Saturn atmosphere?

what if a bigger space probe was designed with multiple sensors on different layers

and in the middle of the probe are the antennas for transmission

so while the outer layers melt away transmission can still happen from the center of the probe

I’d to see how deep a spacecraft could go into the Sun’s atmosphere. I designed the shielding for that once. There really is no limit, it just gets harder and harder the deeper you go.

Am worried that Cassini could not detect trace elements carbon, oxygen, nitrogen in Saturn’s atmosphere because of contamination of reading by its own burning fuel.

According to reports, the final fuel level in Cassini was 1% +- 2%.

Why didn’t they do a complete burn or jettison the fuel tank?

Peak Warming Man said:

mollwollfumble said:

As Cassini ends, Canberra is still receiving signals from Voyager 2, right now.

How long has it got?

around 2020 when the power will be too low to get a signal back to earth.

Tau.Neutrino said:

mollwollfumble said:

Tau.Neutrino said:

How far can a radio transmit signals go through Saturn atmosphere?

what if a bigger space probe was designed with multiple sensors on different layers

and in the middle of the probe are the antennas for transmission

so while the outer layers melt away transmission can still happen from the center of the probe

I’d to see how deep a spacecraft could go into the Sun’s atmosphere. I designed the shielding for that once. There really is no limit, it just gets harder and harder the deeper you go.

Am worried that Cassini could not detect trace elements carbon, oxygen, nitrogen in Saturn’s atmosphere because of contamination of reading by its own burning fuel.

According to reports, the final fuel level in Cassini was 1% +- 2%.

Why didn’t they do a complete burn or jettison the fuel tank?

https://space.stackexchange.com/questions/22667/is-cassini-running-out-of-fuel

ChrispenEvan said:

Tau.Neutrino said:

mollwollfumble said:

I’d to see how deep a spacecraft could go into the Sun’s atmosphere. I designed the shielding for that once. There really is no limit, it just gets harder and harder the deeper you go.

Am worried that Cassini could not detect trace elements carbon, oxygen, nitrogen in Saturn’s atmosphere because of contamination of reading by its own burning fuel.

According to reports, the final fuel level in Cassini was 1% +- 2%.

Why didn’t they do a complete burn or jettison the fuel tank?

https://space.stackexchange.com/questions/22667/is-cassini-running-out-of-fuel

It will be interesting to see next designs.

Cassini launch, October 15, 1997.

Bubblecar said:

Cassini launch, October 15, 1997.

Shopped.

Bubblecar said:

Cassini launch, October 15, 1997.

It would have looked like a plume going in.
Like how meteorites come in

Tau.Neutrino said:

Bubblecar said:

Cassini launch, October 15, 1997.

It would have looked like a plume going in.
Like how meteorites come in

—-

More like being ripped apart by a tornado.

tauto said:

Tau.Neutrino said:

Bubblecar said:

Cassini launch, October 15, 1997.

It would have looked like a plume going in.
Like how meteorites come in

—-

More like being ripped apart by a tornado.

A satellite view would have been good.

Tau.Neutrino said:

tauto said:

Tau.Neutrino said:

It would have looked like a plume going in.
Like how meteorites come in

—-

More like being ripped apart by a tornado.

A satellite view would have been good.

Yes. There are attempts to see the flash from Earth, but there are no telescopes big enough in Australia.

The next live section is just about to start. I managed to stay awake through the interminable repeats.

BBC documentary: Destination Titan

https://www.youtube.com/watch?v=uE5POhMnN78

Final images from Cassini on https://saturn.jpl.nasa.gov/galleries/images/

Impact site in infrared.

Impact site in visible light.

Goodbye propeller. A propeller is a moonlet too small to be called a moon.
https://saturn.jpl.nasa.gov/resources/7791?category=images

Goodbye Daphnis.
https://saturn.jpl.nasa.gov/resources/7790?category=images

Goodbye Saturn.
https://saturn.jpl.nasa.gov/resources/7789?category=images

Goodbye rings.
https://saturn.jpl.nasa.gov/resources/7788?category=images

Goodbye Titan.
https://saturn.jpl.nasa.gov/resources/7787?category=images

Goodbye Enceladus.

For full size final visual image see https://apod.nasa.gov/apod/image/1709/pia21895_CassiniImpactsite_finalimage_1042.png

The impact site is dead centre. at the bottom is the inner edge of the rings.