I take it that we’ve all heard about the successful launch on 25 Dec.

What’s the timeline?

https://www.space.com/news/live/james-webb-space-telescope-updates

Video for first 29 days in space as it heads to its final location. Commissioning will be carried out en route.

https://www.youtube.com/watch?v=7bz03OnyD2A

First mid-course correction burn successful.
https://blogs.nasa.gov/webb/2021/12/25/the-first-mid-course-correction-burn/

At 7:50 pm EST, Webb’s first mid-course correction burn began. It lasted 65 minutes and is now complete. This burn is one of two milestones that are time critical — the first was the solar array deployment, which happened shortly after launch. This burn adjusts Webb’s trajectory toward the second Lagrange point … we ease up to the correct velocity in three stages, being careful never to deliver too much thrust — there will be three mid-course correction maneuvers in total. After this burn, no key milestones are time critical, so the order, location, timing, and duration of deployments may change.

https://webb.nasa.gov/content/webbLaunch/whereIsWebb.html

Next step. Sunshield.

Good luck to the James Webb team.

raises glass in their direction

This looks like a good place to ask my question.

I read somewhere (quite possibly New Scientist), that when this thing is finally deployed, the unfolding will have to be done with “nanometre precision”.

Is that true, or just a bit of journalistic hype?

If the former, how do they manage to do that.

If the latter, what precision do they work to?

The Rev Dodgson said:

This looks like a good place to ask my question.

I read somewhere (quite possibly New Scientist), that when this thing is finally deployed, the unfolding will have to be done with “nanometre precision”.

Is that true, or just a bit of journalistic hype?

If the former, how do they manage to do that.

If the latter, what precision do they work to?

i would imagine the mirrors need to be pretty spot on to get in-focus results. look at Hubble…

Hubble’s primary mirror was built by what was then called Perkin-Elmer Corporation, in Danbury, Connecticut. Once Hubble began returning images that were less clear than expected, NASA undertook an investigation to diagnose the problem. Ultimately the problem was traced to miscalibrated equipment during the mirror’s manufacture. The result was a mirror with an aberration one-50th the thickness of a human hair, in the grinding of the mirror.

JudgeMental said:

The Rev Dodgson said:

This looks like a good place to ask my question.

I read somewhere (quite possibly New Scientist), that when this thing is finally deployed, the unfolding will have to be done with “nanometre precision”.

Is that true, or just a bit of journalistic hype?

If the former, how do they manage to do that.

If the latter, what precision do they work to?

i would imagine the mirrors need to be pretty spot on to get in-focus results. look at Hubble…

Hubble’s primary mirror was built by what was then called Perkin-Elmer Corporation, in Danbury, Connecticut. Once Hubble began returning images that were less clear than expected, NASA undertook an investigation to diagnose the problem. Ultimately the problem was traced to miscalibrated equipment during the mirror’s manufacture. The result was a mirror with an aberration one-50th the thickness of a human hair, in the grinding of the mirror.

That’s very small but not as small as a hare’s breath.

JudgeMental said:

The Rev Dodgson said:

This looks like a good place to ask my question.

I read somewhere (quite possibly New Scientist), that when this thing is finally deployed, the unfolding will have to be done with “nanometre precision”.

Is that true, or just a bit of journalistic hype?

If the former, how do they manage to do that.

If the latter, what precision do they work to?

i would imagine the mirrors need to be pretty spot on to get in-focus results. look at Hubble…

Hubble’s primary mirror was built by what was then called Perkin-Elmer Corporation, in Danbury, Connecticut. Once Hubble began returning images that were less clear than expected, NASA undertook an investigation to diagnose the problem. Ultimately the problem was traced to miscalibrated equipment during the mirror’s manufacture. The result was a mirror with an aberration one-50th the thickness of a human hair, in the grinding of the mirror.

OK, that’s about 2000 nanometres.

Peak Warming Man said:

JudgeMental said:

The Rev Dodgson said:

This looks like a good place to ask my question.

I read somewhere (quite possibly New Scientist), that when this thing is finally deployed, the unfolding will have to be done with “nanometre precision”.

Is that true, or just a bit of journalistic hype?

If the former, how do they manage to do that.

If the latter, what precision do they work to?

i would imagine the mirrors need to be pretty spot on to get in-focus results. look at Hubble…

Hubble’s primary mirror was built by what was then called Perkin-Elmer Corporation, in Danbury, Connecticut. Once Hubble began returning images that were less clear than expected, NASA undertook an investigation to diagnose the problem. Ultimately the problem was traced to miscalibrated equipment during the mirror’s manufacture. The result was a mirror with an aberration one-50th the thickness of a human hair, in the grinding of the mirror.

That’s very small but not as small as a hare’s breath.

The preferred unit of negligible quantities in my business is the bee’s dick, but I suspect that would be regarded as quite large by the telescope people.

One of the most striking features of JWST is its primary mirror, which is 6.5 metres in diameter and comprises 18 hexagonal segments. Once launched into orbit, these 18 movable segments will have to be aligned with extremely high precision (on the order of nanometres) to form the main mirror.

https://www.france24.com/en/science/20211212-next-gen-james-webb-telescope-will-unveil-mysteries-of-galaxy-formation

The Rev Dodgson said:

Peak Warming Man said:

JudgeMental said:

i would imagine the mirrors need to be pretty spot on to get in-focus results. look at Hubble…

Hubble’s primary mirror was built by what was then called Perkin-Elmer Corporation, in Danbury, Connecticut. Once Hubble began returning images that were less clear than expected, NASA undertook an investigation to diagnose the problem. Ultimately the problem was traced to miscalibrated equipment during the mirror’s manufacture. The result was a mirror with an aberration one-50th the thickness of a human hair, in the grinding of the mirror.

That’s very small but not as small as a hare’s breath.

The preferred unit of negligible quantities in my business is the bee’s dick, but I suspect that would be regarded as quite large by the telescope people.

But those Cusp type people also deal in anything from hare’s breaths to parsecs, there’s shed loads of them.

JudgeMental said:

The Rev Dodgson said:

This looks like a good place to ask my question.

I read somewhere (quite possibly New Scientist), that when this thing is finally deployed, the unfolding will have to be done with “nanometre precision”.

Is that true, or just a bit of journalistic hype?

If the former, how do they manage to do that.

If the latter, what precision do they work to?

i would imagine the mirrors need to be pretty spot on to get in-focus results. look at Hubble…

Hubble’s primary mirror was built by what was then called Perkin-Elmer Corporation, in Danbury, Connecticut. Once Hubble began returning images that were less clear than expected, NASA undertook an investigation to diagnose the problem. Ultimately the problem was traced to miscalibrated equipment during the mirror’s manufacture. The result was a mirror with an aberration one-50th the thickness of a human hair, in the grinding of the mirror.

The unfolding and deployment of the thing seems to be a ludicrously complex and precise exercise.

I think it will fail.

JudgeMental said:

One of the most striking features of JWST is its primary mirror, which is 6.5 metres in diameter and comprises 18 hexagonal segments. Once launched into orbit, these 18 movable segments will have to be aligned with extremely high precision (on the order of nanometres) to form the main mirror.

https://www.france24.com/en/science/20211212-next-gen-james-webb-telescope-will-unveil-mysteries-of-galaxy-formation

So maybe 10 or 20 nanometres misalignment is OK perhaps.

Still pretty bloody precise on something 6.5 m diameter, 1.5 million km away.

The Rev Dodgson said:

JudgeMental said:

One of the most striking features of JWST is its primary mirror, which is 6.5 metres in diameter and comprises 18 hexagonal segments. Once launched into orbit, these 18 movable segments will have to be aligned with extremely high precision (on the order of nanometres) to form the main mirror.

https://www.france24.com/en/science/20211212-next-gen-james-webb-telescope-will-unveil-mysteries-of-galaxy-formation

So maybe 10 or 20 nanometres misalignment is OK perhaps.

Still pretty bloody precise on something 6.5 m diameter, 1.5 million km away.

Agree.

Gravitational wave detector mirrors have to be aligned to very much greater precision than that. Such fine alignment normally requires the use of piezo-electrics, which are capable of precision finer than the diameter of an atomic nucleus.

Out past the moon.

Sunshield deployed successfully.

Now 37% of the distance out to the L2 orbit. So I assume it slows down later as it gets closer to the final orbit.

The deployment of the solar shield makes me wonder – They do one big arm at a time, surely by doing that the torque reaction would have to be countered by the onboard gyro and/or thrusters? Perhaps less of a risk that having both rotate at once?

Vid of deployment

Spiny Norman said:

The deployment of the solar shield makes me wonder – They do one big arm at a time, surely by doing that the torque reaction would have to be countered by the onboard gyro and/or thrusters? Perhaps less of a risk that having both rotate at once?

Vid of deployment

Well, it’s managed to cool itself down to -244 degrees F which is, ah, 120 Kelvin.
That helps not only with stability but also for viewing in the infrared.

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

Important Updates and Less Known Facts About James Webb Telescope Launch

Anton Petrov

xkcd reaction to the James Webb launch.on 25 December.

mollwollfumble said:

xkcd reaction to the James Webb launch.on 25 December.

apod’s reaction toi the James Webb launch.

Photo of Webb from the Ariane 5 rocket.

Comet Leonard and JWST launch plume.

On its way past the constellation of Orion.

https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html

WEBB IS FULLY DEPLOYED!

The largest, most complex telescope ever launched into space is fully deployed.

Nominal Event Time: Launch + 14 days (Saturday 1/8/22)

ewetube video of experts discussing the successful deployment. Streamed live 8 hours ago.
https://www.youtube.com/watch?v=hET2MS1tIjA

mollwollfumble said:

https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html

WEBB IS FULLY DEPLOYED!

The largest, most complex telescope ever launched into space is fully deployed.

Nominal Event Time: Launch + 14 days (Saturday 1/8/22)

ewetube video of experts discussing the successful deployment. Streamed live 8 hours ago.
https://www.youtube.com/watch?v=hET2MS1tIjA

Woohoo, we’ll be able to see where we’ve been now.

From the Max Planck Institute for Astronomy: a filter wheel that is onboard the James Webb Space Telescope. It’s a beautiful piece of engineering IMO.
“The filter wheel makes MIRI a scientific instrument. With the exception of the optical elements, the MPIA has planned, designed, built and tested the filter wheel. The 18 optical elements include filters to narrow the wavelength range, coronographs to cover bright objects and a prism.”

Very darn cool, and literally as well

Spiny Norman said:

From the Max Planck Institute for Astronomy: a filter wheel that is onboard the James Webb Space Telescope. It’s a beautiful piece of engineering IMO.
“The filter wheel makes MIRI a scientific instrument. With the exception of the optical elements, the MPIA has planned, designed, built and tested the filter wheel. The 18 optical elements include filters to narrow the wavelength range, coronographs to cover bright objects and a prism.”

Very darn cool, and literally as well

>MIRI is so sensitive that it could detect a candle on one of Jupiter’s moons.

It is impressive. Looks very precisely made and very expensive. And extremely clean.

Bubblecar said:

Spiny Norman said:

From the Max Planck Institute for Astronomy: a filter wheel that is onboard the James Webb Space Telescope. It’s a beautiful piece of engineering IMO.
“The filter wheel makes MIRI a scientific instrument. With the exception of the optical elements, the MPIA has planned, designed, built and tested the filter wheel. The 18 optical elements include filters to narrow the wavelength range, coronographs to cover bright objects and a prism.”

Very darn cool, and literally as well

>MIRI is so sensitive that it could detect a candle on one of Jupiter’s moons.

It is impressive. Looks very precisely made and very expensive. And extremely clean.

Love the above image of the filters, guys.

Getting very close to L2 orbit now. Less than 2 1/2 days to go.

Three months! Oh dear. Well at least there ought to be plenty of trial images in the meantime as they get the focus closer and closer to perfect.

The number one image I want to see from James Webb is SN 1987a. It ought to look spectacular by now.

Data from JWST will be available from the MAST Mikulski Archive Space Telescopes website. But I don’t think there’s any data there yet.
There is simulated James Webb data already available from MAST, software to help for data viewing,

Look out first for JWST data with the file name “uncal”

The following is a simulated JWST raw image released last month.

mollwollfumble said:

Bubblecar said:

Spiny Norman said:

From the Max Planck Institute for Astronomy: a filter wheel that is onboard the James Webb Space Telescope. It’s a beautiful piece of engineering IMO.
“The filter wheel makes MIRI a scientific instrument. With the exception of the optical elements, the MPIA has planned, designed, built and tested the filter wheel. The 18 optical elements include filters to narrow the wavelength range, coronographs to cover bright objects and a prism.”

Very darn cool, and literally as well

>MIRI is so sensitive that it could detect a candle on one of Jupiter’s moons.

It is impressive. Looks very precisely made and very expensive. And extremely clean.

Love the above image of the filters, guys.

Getting very close to L2 orbit now. Less than 2 1/2 days to go.

Three months! Oh dear. Well at least there ought to be plenty of trial images in the meantime as they get the focus closer and closer to perfect.

The number one image I want to see from James Webb is SN 1987a. It ought to look spectacular by now.

Data from JWST will be available from the MAST Mikulski Archive Space Telescopes website. But I don’t think there’s any data there yet.
There is simulated James Webb data already available from MAST, software to help for data viewing,

Look out first for JWST data with the file name “uncal”

The following is a simulated JWST raw image released last month.

James Webb commissioning timetable. From https://planetary.s3.amazonaws.com/web/assets/pictures/_2400×2074_crop_center-center_82_line/519572/JWST-comissioning-v10-01.jpg.webp