James Webb Space Telescope News

[Beertintedgoggles]

I think the biggest reason that was given for the 6 month waiting time is that the telescope needs time to cool. This telescope will be operating in the very long wavelength spectrum (IR and much lower). In order to do this, the background thermal noise must be very low. Imagine using a telescope near a city with all the light pollution, you have to block all that "noisy" light in order to get good results. That's the equivalent of using this telescope before it has reached its operating temp. Any residual heat will pollute the "images" with IR noise. I know, put it in the shade and just use it..... The operating temp is 45 Kelvin (-380 F). It takes a while to shed that much thermal radiation into space to get to that operating temperature even with a huge sunshade blocking the thermal radiation of the Sun (and also Earth).

 

[lexluthermiester]

Ok, if you say so...

He DIDN'T say so. NASA did. Can we have done with the attitude? This is a thread about science. It is not a place to be brandishing the ego...

 

[Shrek]

Four-six months is an extremely long period of time. I hope you do agree that the scientists who work with it don't need thaaat much time..

They have a right to data they collected, and not give it right away to competitors.

 

[Space Lynx]

They have a right to data they collected, and not give it right away to competitors.

Yeah, I agree with this to a degree

I think the better argument is sensationalist astronomers wanting to get their 15 mins of fame might contact news organizations, and be like 'oooo look at these new images this is possible and this is possible', and hyping up a false narrative for their 15 mins of fame, where as the scientist who actually scheduled the time needs time to run the math, write a proper thesis, etc.

The lack of trust in science is at an all time high, and I think a big part is the media and situations like this in all fields of science, so the findings need to be protected at first, then disseminated properly over time. I think we should all be happy that deep down, people, most people, seem to have this thirst inside of them for wanting to know more about the Cosmos.

-------

I propose a question to all of you now:

Does this thirst for wanting to know come from a fear of not understanding who we are? Would an image showing highly likelihood of another civilization or even just a habitable planet satisfy our thirst or cause us distress? What are we seeking really by peering so deep into the Cosmos? I know the scientist will answer this easily, but the thirst of the Common Person's answer... of why they are excited to get the images as fast as possible...

I consider myself a Common Person, I am still seeking my own answer to this question.

 

[Caring1]

I propose a question to all of you now:

Does this thirst for wanting to know come from a fear of not understanding who we are? Would an image showing highly likelihood of another civilization or even just a habitable planet satisfy our thirst or cause us distress? What are we seeking really by peering so deep into the Cosmos?

Neither.
Finding a habitable planet or another civilization out there will only create more questions and a deeper need for answers.

 

[Space Lynx]

Neither.
Finding a habitable planet or another civilization out there will only create more questions and a deeper need for answers.

This is actually what I was trying to get at, I just worded it very vaguely, "understanding who we are".

I wonder... what is this feeling across time, this thirst for exploration? Why is this innate in so many of us as we continue to age? Does it truly all come back to fear of death, and knowing something new erases that fear, always pursuing that something new? I wonder what the Buddha would say about feeling and desire of exploration, maybe he would disagree with me it is not innate... we are born with a few things innate, disgust, fear, etc. What if there are other innate things we are born with, but they don't manifest until certain points in life, that can't be explained by John Locke's tabula rasa theory?

hmm...

What if exploration is enough of an answer, of always creating more questions and more answers in a never ending loop? What if that is the purpose of our frontal cortex development? much to ponder...

 

[KLiKzg]

I think you misunderstand, the scientists will be getting the pictures within a month, but they have rights to them to do their research, but public pictures will take 4-6 months.

I sort of wish they would just release them right away though, but the scientists do bid/take turns getting turns with the telescope, and it makes sense they deserve alone time with them to get their papers written and published in journals before releasing to public.

FLAT-EARTHERS would say that this censorship is to prohibit the pictures of "alien round world" in another star system.

Just needed to be a little funny about them.

I think the biggest reason that was given for the 6 month waiting time is that the telescope needs time to cool. This telescope will be operating in the very long wavelength spectrum (IR and much lower). In order to do this, the background thermal noise must be very low. Imagine using a telescope near a city with all the light pollution, you have to block all that "noisy" light in order to get good results. That's the equivalent of using this telescope before it has reached its operating temp. Any residual heat will pollute the "images" with IR noise. I know, put it in the shade and just use it..... The operating temp is 45 Kelvin (-380 F). It takes a while to shed that much thermal radiation into space to get to that operating temperature even with a huge sunshade blocking the thermal radiation of the Sun (and also Earth).

If the "deep space" within a Solar system is about 3K, while out of it is about 1,5K. Then it has enough temperature delta to achieve 45K within less then a day, if and only if the shields are working.

But we will see...maybe it needs some special alignment of sensors. Hubble was short sighted, how this one is NOT.

 

[R-T-B]

If the "deep space" within a Solar system is about 3K, while out of it is about 1,5K. Then it has enough temperature delta to achieve 45K within less then a day, if and only if the shields are working.

Thermal dissapation via radiation in space is incredibly slow. I'm curious how you reached this conclusion.

 

[the54thvoid]

From NASA's own page:

Spoiler: Long detailed breakdown

WHAT HAPPENS AFTER LAUNCH, HOW LONG UNTIL THERE WILL BE DATA?
In the first hour: Starting at liftoff, the Ariane rocket will provide thrust for about 26 minutes. Telemetry from Webb begins after payload fairing separation, almost 3 and a half minutes after launch. Webb will separate from the Ariane 5 launch vehicle a half hour after launch and the solar array will deploy automatically immediately afterward. We will also command the release of several systems that were locked for launch in preparation for deployments.

In the first day: Two hours after launch we will deploy the high gain antenna. Twelve hours after launch there will be the first trajectory correction maneuver by small rocket engines aboard Webb itself.

In the first week: The second trajectory correction maneuver will take place at 2.5 days after launch. We will start the sequence of major deployment just after that. The first deployments are the fore and aft sunshield pallets, followed by the release of remaining sub-system launch locks. The next deployment is the telescope in which the telescope and the spacecraft bus move apart from each other by about 2 meters when the deployable tower assembly extends. The full sunshield deployment with unfolding and tensioning of the membranes can then be initiated. At 6 days we deploy the secondary mirror, followed by the side wings of the primary mirror.

In the first month: As the telescope cools down in the shade of the deployed sunshield, we will turn on the warm electronics and initialize the flight software. At the end of the first month, we will do the mid-course correction that ensures that Webb will achieve its final orbit around L2. Although the telescope cools to near its operating temperature, the ISIM is warmed with electric heaters to prevent condensation on the instruments as residual water trapped in the materials making up the observatory escapes to the vacuum of space.

In the second month: At 33 days after launch we will turn on and operate the Fine Guidance Sensor, then NIRCam and NIRSpec. The first NIRCam image will be of a crowded star field to make sure that light gets through the telescope into the instruments. Since the primary mirror segments will not yet be aligned, the picture will still be out of focus. At 44 days after launch we will begin the process of adjusting the primary mirror segments, first identifying each mirror segment with its image of a star in the camera. We will also focus the secondary mirror.

In the third month: From 60 to 90 days after launch we will align the primary mirror segments so that they can work together as a single optical surface. We will also turn on and operate the MIRI. By the end of the third month we will be able to take the first science-quality images. Also by this time, Webb will complete its journey to its L2 orbit position.

In the fourth through the sixth month: At about 85 days after launch we will have completed the optimization of the telescope image in the NIRCam. Over the next month and a half we will optimize the image for the other instruments. We will test and calibrate all of the instrument capabilities by observing representative science targets.

After six months: Webb will begin its science mission and start to conduct routine science operations.

@lexluthermiester has already posted a similar link. We've got the timescales covered so curve ball opinions about what's going on aren't helping the science discussion.

 

[KLiKzg]

Thermal dissapation via radiation in space is incredibly slow. I'm curious how you reached this conclusion.

No, it is not. Thermal conduction is incredibly slow, as there is no medium to transfer heat.

Thermal radiation on other hand is electromagnetic radiation, so no medium is needed:

 

[Shrek]

Would an image showing highly likelihood of another civilization or even just a habitable planet satisfy our thirst or cause us distress?

Chances are that civilization would we far ahead of us and then why would we strive for a James Webb 2 knowing it had already been done.

 

[ARF]

Finding a habitable planet or another civilization out there will only create more questions and a deeper need for answers.

We are obviously not alone. Even our own origins are questionable because the likelihood that we were created by the Anunnaki is real.
Anunnaki - Wikipedia

The list of exoplanets already found without the JWST is quite long.

This is a list of exoplanets. As of 1 December 2021, there are 4,878 confirmed exoplanets in 3,604 planetary systems, with 807 systems having more than one planet.[1] Most of these were discovered by the Kepler space telescope. There are an additional 2,366 potential exoplanets from Kepler's first mission yet to be confirmed, as well as 889 from its "Second Light" mission and 1,385 from the Transiting Exoplanet Survey Satellite (TESS) mission.[2]

For yearly lists on physical, orbital and other properties, as well as on discovery circumstances and other aspects, see § Specific exoplanet lists.

Lists of exoplanets - Wikipedia

 

[lexluthermiester]

No, it is not.

Yes, it is. When temps get below -200K, heat bleed-off is a very slow process. This is KNOWN science fact.

Please review;

https://space.nss.org/settlement/nasa/spaceresvol2/thermalmanagement.html

While this is not directly related to JWT, it contains information that will help a reader understand the principles of thermodynamics in space.

 

[ARF]

But if it burns its fuel for some trajectory corrections, that also should warm it up...
How is it possible at all to wait for a cool down when its function alone dissipates heat?!

 

[TheoneandonlyMrK]

But if it burns its fuel for some trajectory corrections, that also should warm it up...
How is it possible at all to wait for a cool down when its function alone dissipates heat?!

I suggest you do some research instead of speculative impossibility statements.

If I light a match do my fingers instantaneously set on fire or is that constrained by how long my dumb ass holds the match?!.

And how is a force expelled in heat going to double back and heat the satellite, it is not, and any heat radiated through the body of the satellite from its engines is obviously pre considered and radiated away.

Plus the six reaction wheels would do the majority of angular adjustment with engine's used for trajectory corrections.

 

[ARF]

Ok, so we need to assume that its scientific instruments don't warm up, like our phones do, our notebooks do, hell, all chips do... and it has solar photovoltaics array to supply its instruments with power...

 

[the54thvoid]

Ok, so we need to assume that its scientific instruments don't warm up, like our phones do, our notebooks do, hell, all chips do... and it has solar photovoltaics array to supply its instruments with power...

All we're saying is let NASA do its science and stop second guessing it's methods. Move on, please.

 

[ARF]

All we're saying is let NASA do its science and stop second guessing it's methods. Move on, please.

I didn't say the opposite. I just say - let them do it faster

 

[TheoneandonlyMrK]

I didn't say the opposite. I just say - let them do it faster

Crack on with getting a job there, doing better than them and Changing things up then.

Or assume NASA didn't hire idiots, and indeed do know what they're doing and how best to do it, and under what timeframe.

 

[KLiKzg]

Yes, it is. When temps get below -200K, heat bleed-off is a very slow process. This is KNOWN science fact.

Please review;

https://space.nss.org/settlement/nasa/spaceresvol2/thermalmanagement.html

While this is not directly related to JWT, it contains information that will help a reader understand the principles of thermodynamics in space.

Of course it does, as the thermal radiation is on 4th power of temperature difference. Lower the difference, lower the thermal radiation.
Just plain & simple physics.

But if it burns its fuel for some trajectory corrections, that also should warm it up...
How is it possible at all to wait for a cool down when its function alone dissipates heat?!

Guys, lets check out a little photo with pointers. Everything will be nicely shown (engines on the bottom, telescope on top):

 

[birdie]

Where is Webb?

In real time: https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html?units=metric

 

[Space Lynx]

Where is Webb?

In real time: https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html?units=metric

I've had that bookmarked for awhile now, its fun to watch the little animation at the top... haha

 

[Divide Overflow]

NASA Says Webb’s Excess Fuel Likely to Extend its Lifetime Expectations​

After a successful launch of NASA’s James Webb Space Telescope Dec. 25, and completion of two mid-course correction maneuvers, the Webb team has analyzed its initial trajectory and determined the observatory should have enough propellant to allow support of science operations in orbit for significantly more than a 10-year science lifetime. (The minimum baseline for the mission is five years.)

The analysis shows that less propellant than originally planned for is needed to correct Webb’s trajectory toward its final orbit around the second Lagrange point known as L2, a point of gravitational balance on the far side of Earth away from the Sun. Consequently, Webb will have much more than the baseline estimate of propellant – though many factors could ultimately affect Webb’s duration of operation.

Webb has rocket propellant onboard not only for midcourse correction and insertion into orbit around L2, but also for necessary functions during the life of the mission, including “station keeping” maneuvers – small thruster burns to adjust Webb’s orbit — as well as what’s known as momentum management, which maintains Webb’s orientation in space.

The extra propellant is largely due to the precision of the Arianespace Ariane 5 launch, which exceeded the requirements needed to put Webb on the right path, as well as the precision of the first mid-course correction maneuver – a relatively small, 65-minute burn after launch that added approximately 45 mph (20 meters/sec) to the observatory’s speed. A second correction maneuver occurred on Dec. 27, adding around 6.3 mph (2.8 meters/sec) to the speed.

The accuracy of the launch trajectory had another result: the timing of the solar array deployment. That deployment was executed automatically after separation from the Ariane 5 based on a stored command to deploy either when Webb reached a certain attitude toward the Sun ideal for capturing sunlight to power the observatory – or automatically at 33 minutes after launch. Because Webb was already in the correct attitude after separation from the Ariane 5 second stage, the solar array was able to deploy about a minute and a half after separation, approximately 29 minutes after launch.

 

[defaultluser]

NASA Says Webb’s Excess Fuel Likely to Extend its Lifetime Expectations​

After a successful launch of NASA’s James Webb Space Telescope Dec. 25, and completion of two mid-course correction maneuvers, the Webb team has analyzed its initial trajectory and determined the observatory should have enough propellant to allow support of science operations in orbit for significantly more than a 10-year science lifetime. (The minimum baseline for the mission is five years.)

The analysis shows that less propellant than originally planned for is needed to correct Webb’s trajectory toward its final orbit around the second Lagrange point known as L2, a point of gravitational balance on the far side of Earth away from the Sun. Consequently, Webb will have much more than the baseline estimate of propellant – though many factors could ultimately affect Webb’s duration of operation.

Webb has rocket propellant onboard not only for midcourse correction and insertion into orbit around L2, but also for necessary functions during the life of the mission, including “station keeping” maneuvers – small thruster burns to adjust Webb’s orbit — as well as what’s known as momentum management, which maintains Webb’s orientation in space.

The extra propellant is largely due to the precision of the Arianespace Ariane 5 launch, which exceeded the requirements needed to put Webb on the right path, as well as the precision of the first mid-course correction maneuver – a relatively small, 65-minute burn after launch that added approximately 45 mph (20 meters/sec) to the observatory’s speed. A second correction maneuver occurred on Dec. 27, adding around 6.3 mph (2.8 meters/sec) to the speed.

The accuracy of the launch trajectory had another result: the timing of the solar array deployment. That deployment was executed automatically after separation from the Ariane 5 based on a stored command to deploy either when Webb reached a certain attitude toward the Sun ideal for capturing sunlight to power the observatory – or automatically at 33 minutes after launch. Because Webb was already in the correct attitude after separation from the Ariane 5 second stage, the solar array was able to deploy about a minute and a half after separation, approximately 29 minutes after launch.

And if the hardware survives the now extended fuel lifetime, there's always this option for replacing that missing station-keeping thrust

https://news.northropgrumman.com/ne...extension-vehicle-with-intelsat-901-satellite

I'm sure Northrop made certain this thing could easily dock with the MEV

 

[Shrek]

I am wondering how the mirrors will withstand micro-meteorites.