Fatal Flaw Discovered in James Webb Telescope - It's the Hubble Fiasco All Over Again.

In fairness to me, I did read the dubious OP and made a follow up joke on it. I saw an opportunity to reference the Far out Space Nuts and went for it.
Anyway the real question in regard to telescopes should be why during the covidiacy of the past 2 years has the majority of the worlds telescopes been shut down or possibly sabotaged (Arecibo). It is surprising to hear there was a new telescope being brought online in spite of all the telescope shutdowns and in the end would not surprise me in the least there is actually something wrong with it.

a reply to: championoftruth

It seems NASA has done another hubble goof.

I doubt it.
Webb sees in the Infrared so radiation from distant stars is what it's looking for , I seriously doubt light bouncing off the shield will cause a problem and if it could NASA would have mitigated against it given the preponderance of caution they've shown over the years with Webb.

In a nearby stellar nursery called the Orion Nebula, young, massive stars are blasting far-ultraviolet light at the cloud of dust and gas from which they were born. This intense flood of radiation is violently disrupting the cloud by breaking apart molecules, ionizing atoms and molecules by stripping their electrons, and heating the gas and dust. An international team using NASA's James Webb Space Telescope, which is scheduled to launch in October, will study a portion of the radiated cloud called the Orion Bar to learn more about the influence massive stars have on their environments, and even on the formation of our own solar system.
www.nasa.gov...

Your thread title made it sound official ... thankfully it isn't.

originally posted by: iso1111
In fairness to me, I did read the dubious OP and made a follow up joke on it. I saw an opportunity to reference the Far out Space Nuts and went for it.
Anyway the real question in regard to telescopes should be why during the covidiacy of the past 2 years has the majority of the worlds telescopes been shut down or possibly sabotaged (Arecibo). It is surprising to hear there was a new telescope being brought online in spite of all the telescope shutdowns and in the end would not surprise me in the least there is actually something wrong with it.

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The telescope assembles itself every mirror can be adjusted from the earth. The shielding cannot affect the mirrors in any way they are simply there because our planet is noisy constantly sending out em transmissions,

a reply to: Soylent Green Is People

Suppose someone had said that Nasa had screwed up the hubble mirror before launch...?

Simple ray tracing could confirm this as the dimensions are known very accurately...

A 3D model of it exists?

Also is the main mirror rotatable from 90 to zero degrees vertically?

a reply to: gortex

I never just light. i said any radiation. including infra red coming from a multiplicity of sources..

The telescope must operate at very low temperature and having other IR sources bounce around from the FRONT of the giant heat shield will ruin that...

a reply to: championoftruth
The radiation from other stars on the telescope side won't be enough to heat it. Only the radiation/light hitting the mirror from the direction it is pointing will be precisely reflected to hit the secondary mirror. Anything that hits the mirror from a direction they aren't pointing it doesn't hit the secondary mirror and reflects off into space. The on-board active cryocooler will take care of heat from the earth and sun traveling through the heat shield brackets and into the rest of the structure. This isn't the first infrared telescope, it's just the best one we could design and launch in space.

originally posted by: championoftruth
a reply to: gortex
The telescope must operate at very low temperature and having other IR sources bounce around from the FRONT of the giant heat shield will ruin that...

The Herschel Observatory wasn't handicapped by that issue, even though it had a similar arrangement of shield and telescope.


On top of that, Herschel specialized in the far infrared, which requires colder instrument temperatures than other infrared observation. Webb will be looking mostly at near- and mid-infrared. To study the mid-infrared, the instruments need to still be pretty cold. The near-infrared a little less so.

Again, I'm not saying NASA can't screw up (they have in the past) or that they haven't screwed up something this time. However, you haven't provided any good evidence that they have.

If NASA can mess up Inches to MM, hubble.
then this is easy......................

a reply to: buddha

inches to mm is the result of a lack of definitions, Hubble was a lack of quality control (besides the quality control made by the real responsible for the flaw), as was the Challenger accident.
This one, if real, would be a concept flaw, and I don't remember one from any main space agency in the last 40 years.

PS: this is a joint mission between NASA, ESA and the Canadian Space Agency, it's not just a NASA mission.

a reply to: championoftruth

I think you need to watch this it why we cant have a repeat of hubble. As it can self adjust the mirrors.

originally posted by: dragonridr
it can self adjust the mirrors.

What could possibly go wrong?

originally posted by: championoftruth
I have discovered a fatal flaw which NASA failed to keep in mind.

The reflective heat shield will reflect radiation into the primary and secondary mirrors making it USELESS due to multiple reflections of the heat shield on the MIRROR side !!!

Just to make it clear I am talking about the radiation from distant stars, galaxies on hitting the heat shield and bouncing
into the primary and secondary mirrors causing massive glare and multiple aberrations and distortions making it useless.

It seems NASA has done another hubble goof.

Actually, NASA has not done another "goof" after 10 billion dollars and have thought about this exact problem.

www.nasa.gov...

It took me about 90 seconds of googling (and Google's excellent natural language understanding & models) to get to a specific web page with the answer.

In addition to the sunshield, there are a multitude of other innovative features which enable the telescope to achieve its unmatched sensitivity for faint infrared signals. One such feature is the protective barrier behind Webb’s primary mirror called “Frill.” This lightweight blanketing plays an important role on the observatory as it blocks unwanted light from reaching the telescope’s sensitive infrared sensors.

“Due to its origami unfolding architecture, the Webb telescope does not have a cylindrical light baffle, like is seen with Hubble or even your home telescope which is used to block unwanted light. Instead, Webb is a first of a kind “open” telescope that relies on the sunshield to block unwanted Sun, Earth and moonlight and relies on the Frill, shown here, to block light from stars and galaxies that are behind the telescope, that would hit the secondary mirror and get down into the science instruments that are extremely sensitive,” said Lee Feinberg, Optical Telescope Element Manager, James Webb Space Telescope at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Furthermore, there is a baffle on the tertiary detector to reduce stray light/infrared.

webbtelescope.org...

This is another example of people who truly don't have any sense of the depths of knowledge and investigation that professional scientists put into their profession, particularly on something investigated and worked on for decades by so many people. Yes, this is a 'subtweet' about climate change pseudosceptics who believe, erroneously, that they've figured out some big goof that the mainstream scientists have forgotten about.