James Webb Space Telescope

[Mister T]

1 hour ago, Pap said:

I wonder how many times they wiped the lens with cotton wool before it was packed to go 🙃

To get the best result you have breath on it first. Hope they did that too 😜

[kawasakijambo]

windolene

[Jambo_jim2001]

12 hours ago, kawasakijambo said:

windolene

Are they still making it?

[kawasakijambo]

4 hours ago, Jambo_jim2001 said:

Are they still making it?

Not seen the pink stuff for sometime now.

[PortyJambo]

2 hours ago, kawasakijambo said:

Not seen the pink stuff for sometime now.

 

NASA cleared the shelves

[Cade]

Everything deployed.

 

All the major infrastructure is done.

 

Now it has to be calibrated, cooled and tested.

[Maple Leaf]

1 minute ago, Cade said:

Everything deployed.

 

All the major infrastructure is done.

 

Now it has to be calibrated, cooled and tested.

 

It's an astonishing scientific feat.  Among the greatest in history.

 

Even the ability to figure out where L2 is ... a spot in space where all the gravitational forces cancel each other out ... blows my mind.

[redjambo]

52 minutes ago, Maple Leaf said:

 

It's an astonishing scientific feat.  Among the greatest in history.

 

Even the ability to figure out where L2 is ... a spot in space where all the gravitational forces cancel each other out ... blows my mind.

 

Not only to determine where L2 is, but to essentially go into orbit around that point rather than sit at the point. The mind boggles at the complexity of it.

[kila]

Some interesting reading on it all - https://solarsystem.nasa.gov/resources/754/what-is-a-lagrange-point/

 

Pinched a couple visuals:

 

 

 

 

[Cade]

Oor man in the states made a video about Lagrange points.

 

 

[JFK-1]

On 11/01/2022 at 15:56, redjambo said:

 

Not only to determine where L2 is, but to essentially go into orbit around that point rather than sit at the point. The mind boggles at the complexity of it.

 

How mind blowing is it that the guy who calculated the points did it in the 1700's? And that's nothing in comparison to what Newton did in the 1600's.

[JFK-1]

A little update on the progress of Webb. The telescope is as I post around 770,000 miles from Earth with around 128,000 miles to go before reaching the L2 parking point.

About 15 days to go the telescope speed is now down to about 676 mph and slowing by the day. I think the launch may have been calculated to push it almost there but not quite. Looking like it may come to a halt just short of L2 and might need a very small nudge into final position.

This project has brought massive credit not just to NASA but ESA and the Ariane team. ESA established themselves as the current go to for highly complex launches carrying massively expensive payloads. 

[Footballfirst]

Making good progress towards L2. 94%+ there, 48,000 miles or 78,000k to go.  L2 insertion could happen on Sunday.

 

The individual mirror segments all appear to have been deployed, just the months of fine adjustment and focusing to follow.  Temperatures also dropping on the "cold side".

 

https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html?units=english

[Cade]

Two of the mirror hexes have got slightly dodgy sensors, so those two need extra special aligning.

This problem was spotted after the satellite was built and the cost (in both time and money) to take it all apart again to fix those parts was deemed not worth it.

The boffins have worked out how to compensate for the lack of sensors and will align those two hexes after all the others have been zeroed in.

The sensors will be unable to tell the exact position of those two parts, but running tests when all the others are aligned will tell them how much to move these two by to bring it all info sharp focus.

 

"Boss! These two things are buggered."
"FFS we're twenty years and hundreds of millions over budget already, just launch the fecker and we'll come up with a solution later"

"sound, nae bother"

[Jambo_jim2001]

Will need it shortly,to see the gap to Hibs😁looking forward to the images this is going to produce tho...was amazed at Hubble images,,this should blow those out the water

 

[JFK-1]

The speed of the telescope is currently down to around 523mph, passenger jet speed and slowing by the day. A distance of 43,700 miles still to go 9 days till insertion.

I believe it's going to trundle to a stop just short of the L2 point then be nudged into position using some of the fuel. If that be the case it will be fascinating to see exactly how short of the point it stops. What a calculation btw.

[Footballfirst]

3 hours ago, JFK-1 said:

The speed of the telescope is currently down to around 523mph, passenger jet speed and slowing by the day. A distance of 43,700 miles still to go 9 days till insertion.

I believe it's going to trundle to a stop just short of the L2 point then be nudged into position using some of the fuel. If that be the case it will be fascinating to see exactly how short of the point it stops. What a calculation btw.

The telescope is now 26 days into the mission so, according to the schedule, only 3 days away from the L2 insertion (Launch +29). 

[JFK-1]

4 minutes ago, Footballfirst said:

The telescope is now 26 days into the mission so, according to the schedule, only 3 days away from the L2 insertion (Launch +29). 

 

Yes I was misreading it as the 29th.

[Footballfirst]

Monday for the L2 insertion.

 

 

[Footballfirst]

L2 insertion underway by the looks of it. Press conference organised for 9pm (GMT) this evening.

 

https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html?units=english

[Footballfirst]

Most Recently Completed:

L2 Insertion Burn

Mid Course Correction Burn (MCC2) - L2 Orbit Insertion

Nominal Event Time: Updated: Launch + 30 days

Status: Complete. Webb is in L2 Orbit!

 

Coverage: What's Next? 3pm EST (8pm GMT) | Media Teleconference 4pm EST (9pm GMT)

[JFK-1]

It appears to be still cruising at around 450mph orbiting the L2 point. I will hazard a guess around that speed was planned.

Trying to envisage what might happen if it were to be going faster than that, might exit the point area I suppose since something going around the Earth too fast would escape rather than orbit.

 

Or too slow, fall into the point? Envisaging it as some sort of gravity well, like a crater on the earth say. Water or anything else would fall into it. And anything going below orbital velocity around Earth is going to "fall in"

But have no idea if that's a fit analogy for the scenario.

[Footballfirst]

1 hour ago, JFK-1 said:

It appears to be still cruising at around 450mph orbiting the L2 point. I will hazard a guess around that speed was planned.

Trying to envisage what might happen if it were to be going faster than that, might exit the point area I suppose since something going around the Earth too fast would escape rather than orbit.

 

Or too slow, fall into the point? Envisaging it as some sort of gravity well, like a crater on the earth say. Water or anything else would fall into it. And anything going below orbital velocity around Earth is going to "fall in"

But have no idea if that's a fit analogy for the scenario.

Its orbit of L2  (at a distance of 232,000 miles) is roughly the same as the moon's orbit (average distance 239,000 miles) round the earth.  The moon takes around 27 days to orbit the earth. JWST will take 6 months to orbit L2.  It's all a balancing act of gravitational pulls between the Earth, Moon and Sun.

 

The 450mph will be relative to L2. The moon travels round the Earth at 2,288mph, so the JWST velocity over a similar distance appears to be in the ball park.   JWST will also travel round the Sun in a year as it keeps it's alignment with the Earth. Relative to the Sun, the Earth orbits at 67,000 mph.

 

I think that Earth orbit is around 17,500mph (first manned space craft) and escape velocity is around 25,000mph (first moon trips)

[JFK-1]

20 hours ago, Footballfirst said:

Its orbit of L2  (at a distance of 232,000 miles) is roughly the same as the moon's orbit (average distance 239,000 miles) round the earth.  The moon takes around 27 days to orbit the earth. JWST will take 6 months to orbit L2.  It's all a balancing act of gravitational pulls between the Earth, Moon and Sun.

 

The 450mph will be relative to L2. The moon travels round the Earth at 2,288mph, so the JWST velocity over a similar distance appears to be in the ball park.   JWST will also travel round the Sun in a year as it keeps it's alignment with the Earth. Relative to the Sun, the Earth orbits at 67,000 mph.

 

I think that Earth orbit is around 17,500mph (first manned space craft) and escape velocity is around 25,000mph (first moon trips)

 

I see logic in your calculations, and they gave me a further thought. The Lagrange points may shift as the moon recedes further from the Earth.

Apparently the moon was only around 10,000 miles or so away from the Earth at first, that must have been quite a sky spectacle, and has been drifting further out ever since. 

[Cade]

 

Big orange dot is the Sun, wee blue doe in the middle is Earth.

 

This helps you visualise the path that JWST is going to be on for the next twenty years, orbiting a gravitational point in space but still orbiting the sun.

 

[Footballfirst]

1 hour ago, Cade said:

 

Big orange dot is the Sun, wee blue doe in the middle is Earth.

 

This helps you visualise the path that JWST is going to be on for the next twenty years, orbiting a gravitational point in space but still orbiting the sun.

 

Here's a better illustration that incorporates the graphic above.

 

 

[Lone Striker]

Wow - that's some seriously complex  physics, maths, engineering, electronics and robotics expertise required to get this stage working right.  

 

 

[kila]

5 hours ago, Footballfirst said:

Here's a better illustration that incorporates the graphic above.

 

 

 

Didn't realise how big it was after it unfolded itself

 

[Cade]

*not to scale

 

[JFK-1]

This is the best visualisation I have seen demonstrating how we think Einsteinian gravity works.
 

 

[Footballfirst]

JWST's first image (a selfie).

 

The bright segment is the light reflecting from the star that is being used to calibrate the mirrors.

 

 

[PortyJambo]

Telescope now fully focussed and "performance even better than hoped"

https://www.bbc.co.uk/news/science-environment-60771210

[Cade]

 Astounding that everything went right. Let the science begin!

[JFK-1]

In this image you can see galaxies in the background, the star is around 2,000 light years away, the galaxies probably billions of light years. Yet if you expand it you can clearly see features of the galaxies, and the telescope isn't even focused on them. It's going to be amazing when it does lock in on a galaxy.

[JFK-1]

 

[Footballfirst]

NASA has just published a pair of images comparing the performance of their first infrared space telescope, Spitzer, and the James Webb telescope. Prospects of a lot more to come once the "science" actually starts.

 

NASA Webb Telescope@NASAWebb

Computer, enhance! Compare the same target — seen by Spitzer & in Webb’s calibration images. Spitzer, NASA's first infrared Great Observatory, led the way for Webb’s larger primary mirror & improved detectors to see the infrared sky with even more clarity: https://blogs.nasa.gov/webb/2022/05/09/miris-sharper-view-hints-at-new-possibilities-for-science/

 

 

9/miris-sharper-view-hints-at-new-possibilities-for-science/

Edited May 9, 2022 by Footballfirst

[PortyJambo]

5 minutes ago, Footballfirst said:

NASA has just published a pair of images comparing the performance of their first infrared space telescope, Spitzer, and the James Webb telescope. Prospects of a lot more to come once the "science" actually starts.

 

NASA Webb Telescope@NASAWebb

Computer, enhance! Compare the same target — seen by Spitzer & in Webb’s calibration images. Spitzer, NASA's first infrared Great Observatory, led the way for Webb’s larger primary mirror & improved detectors to see the infrared sky with even more clarity: https://blogs.nasa.gov/webb/2022/05/09/miris-sharper-view-hints-at-new-possibilities-for-science/

 

 

9/miris-sharper-view-hints-at-new-possibilities-for-science/

Pretty spectacular difference in resolution. Can't wait to see the images coming through when they start using it "for real"

[Jambo-Jimbo]

1 hour ago, Footballfirst said:

NASA has just published a pair of images comparing the performance of their first infrared space telescope, Spitzer, and the James Webb telescope. Prospects of a lot more to come once the "science" actually starts.

 

NASA Webb Telescope@NASAWebb

Computer, enhance! Compare the same target — seen by Spitzer & in Webb’s calibration images. Spitzer, NASA's first infrared Great Observatory, led the way for Webb’s larger primary mirror & improved detectors to see the infrared sky with even more clarity: https://blogs.nasa.gov/webb/2022/05/09/miris-sharper-view-hints-at-new-possibilities-for-science/

 

 

9/miris-sharper-view-hints-at-new-possibilities-for-science/

 

Wow, what an improvement, really impressive.

[Unknown user]

On 29/01/2022 at 02:47, JFK-1 said:

This is the best visualisation I have seen demonstrating how we think Einsteinian gravity works.
 

 

 

See also this, on gravitational waves

 

 

Edited May 9, 2022 by Smithee

[Unknown user]

Not sure if I've posted this before but I love this guy, Dustin from Smarter Every Day.

 

His dad worked on the solar shield of the JWT for years, this is an interview where we get to see up close and personal as Dustin interviews his own dad and other experts.

 

 

 

 

[redjambo]

1 hour ago, Smithee said:

 

See also this, on gravitational waves

 

 

 

Thanks for posting that. Fascinating. The guy's excellent at explaining things.

[Unknown user]

40 minutes ago, redjambo said:

 

Thanks for posting that. Fascinating. The guy's excellent at explaining things.

 

He really is, I love him, I kind of understand things way beyond my natural ability thanks to him

[Footballfirst]

NASA must be very happy with the quality of the images being received during commissioning to provide a firm date this far out.

 

 

[ri Alban]

12 minutes ago, Footballfirst said:

NASA must be very happy with the quality of the images being received during commissioning to provide a firm date this far out.

 

 

Sorry, Scotland will be too busy tooting fluting and banging a big Drum .

Edited June 1, 2022 by ri Alban

[JFK-1]

Highly expandable.