Author Topic: James Webb Space Telescope  (Read 41344 times)

Offline bknight

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Re: James Webb Space Telescope
« Reply #165 on: December 29, 2021, 12:52:00 PM »
I know Jay has posted that carrying heat away from electronics is an issue and the Temperatures are available now and I see an Instrument radiator temperature available.  So, does this radiator connect physically to the instrument circuits and transmit heat physically?  Is this how it's done?
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Offline Bryanpoprobson

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Re: James Webb Space Telescope
« Reply #166 on: December 29, 2021, 01:41:42 PM »
Due to the precision of our launch and our first two mid-course corrections, our team has determined that Webb should have enough fuel to allow support of science operations for significantly more than a 10-year science lifetime! 💫 blogs.nasa.gov/webb/2021/12/2…
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Offline smartcooky

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Re: James Webb Space Telescope
« Reply #167 on: December 29, 2021, 07:11:51 PM »
The Deployable Tower Assembly (the structure that holds the mirrors and the instrument housing) has now been deployed. It has been extended "up" about two metres to give clearance for the sun shield to deploy.
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Offline Zakalwe

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Re: James Webb Space Telescope
« Reply #168 on: December 30, 2021, 04:25:59 AM »
I know Jay has posted that carrying heat away from electronics is an issue and the Temperatures are available now and I see an Instrument radiator temperature available.  So, does this radiator connect physically to the instrument circuits and transmit heat physically?  Is this how it's done?

https://webb.nasa.gov/content/about/innovations/cryocooler.html

https://www.nasa.gov/feature/jpl/how-cold-can-you-go-cooler-tested-for-nasa-telescope
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Offline bknight

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Re: James Webb Space Telescope
« Reply #169 on: December 30, 2021, 01:54:11 PM »
I know Jay has posted that carrying heat away from electronics is an issue and the Temperatures are available now and I see an Instrument radiator temperature available.  So, does this radiator connect physically to the instrument circuits and transmit heat physically?  Is this how it's done?

https://webb.nasa.gov/content/about/innovations/cryocooler.html

https://www.nasa.gov/feature/jpl/how-cold-can-you-go-cooler-tested-for-nasa-telescope

Interesting.  The first part of the sun screen was accomplished.
https://blogs.nasa.gov/webb/
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Offline Bryanpoprobson

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Re: James Webb Space Telescope
« Reply #170 on: January 01, 2022, 05:30:17 AM »
Both sides of the sun shield deployed, tensioning and separation to come, this surely is the tricky part nearly over?
"Wise men speak because they have something to say!" "Fools speak, because they have to say something!" (Plato)

Offline Peter B

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Re: James Webb Space Telescope
« Reply #171 on: January 03, 2022, 02:07:53 AM »
What an odd sequence of orbital maneuvers..... launch to 220 km, then drop down to about 180 km, then turn upwards and ramp the velocity up to about 10km/s.

The dive from 220km back down to 180km - is that an example of the Oberth Effect?

I don't know. I think it may have been intentional. In the commentary, they were talking about performing "the sawtooth maneuver". They also talked about something to do with avoiding direct sunlight on parts of the telescope.

Aha!

https://www.youtube.com/watch?v=_abdV-HtEJQ

Video from Anton Petrov confirmed the dive was an Oberth Effect maneuver. He also said the spacecraft twisted back and forth on its vertical axis as a measure to protect against Sun heating.

Offline bknight

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Re: James Webb Space Telescope
« Reply #172 on: January 03, 2022, 08:52:55 PM »
The first three sunshield layers have been tensioned.     The next two will be tensioned tomorrow.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
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Offline bknight

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Re: James Webb Space Telescope
« Reply #173 on: January 04, 2022, 12:04:45 PM »
Listening live all five layers have been tensioned.  Now onto the mirrors deployment.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Bryanpoprobson

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Re: James Webb Space Telescope
« Reply #174 on: January 05, 2022, 12:12:15 PM »
Secondary Mirror deployed successfully.
"Wise men speak because they have something to say!" "Fools speak, because they have to say something!" (Plato)

Offline bknight

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Re: James Webb Space Telescope
« Reply #175 on: January 05, 2022, 01:45:45 PM »
Secondary Mirror deployed successfully.

Slowly but surely the +/- 300 "devices" work to completely deploy the telescope.   ;D
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline raven

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Re: James Webb Space Telescope
« Reply #176 on: January 07, 2022, 10:03:50 PM »
And now one of two wings of the primary mirror have been unfolded. Still on tenterhooks until it's all done, but here's hoping!

Offline bknight

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Re: James Webb Space Telescope
« Reply #177 on: January 08, 2022, 10:57:18 AM »
My morbid thougts on this telescope have been relieved to a large part, now for the calibrating, etc.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline molesworth

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Re: James Webb Space Telescope
« Reply #178 on: January 08, 2022, 02:05:20 PM »
My morbid thougts on this telescope have been relieved to a large part, now for the calibrating, etc.
Agreed!  After all the delays and setbacks I was expecting problems with the various mechanisms sticking.  It looks like we'll finally get a working telescope, and some incredible views of the universe.
Days spent at sea are not deducted from one's allotted span - Phoenician proverb

Offline molesworth

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Re: James Webb Space Telescope
« Reply #179 on: January 24, 2022, 04:51:29 PM »
JWST is now in its L2 orbit, and getting ready to start work.

James Webb telescope parked in observing position
Quote
Thirty days after it was launched, the James Webb telescope has arrived at the position in space where it will observe the Universe.

The Lagrange Point 2, as it's known, is a million miles (1.5 million km) from Earth on its nightside.

Webb was finally nudged into an orbit around this location thanks to a short, five-minute thruster burn.

Controllers back on Earth will now spend the coming months tuning the telescope to get it ready for science.

Key tasks include switching on the observatory's four instruments, and also focusing its mirrors - in particular, its 6.5m-wide segmented primary reflector.

There's still a lot of adjustment and checking to do, but it won't be too long before we start to see some amazing images.
Days spent at sea are not deducted from one's allotted span - Phoenician proverb