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The James Webb Telescope

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Was hoping there would be onboard cameras too. That rocket really has a chooch factor to it though, that really took off. 😱
 
That was great, crazy to think it's finally in space now! Still a lot of steps to literally unfold but I feel the riskiest bit is probably over. There is still a chance for things to go wrong though so not quite out of the woods yet.
 
watched the launch this morning. it was awesome. makes up for the fact that my nephews burst into my room to wake me up to open christmas presents 😀

now for the really tricky part...but so far so good! let's go JWST!

edit: also, seeing JWST from the camera atop the final stage of the ariane vehicle was super cool. wasn't expect that.
 
ImpulsE69 said:
When something is in development for this long, do they change the technology to keep up with the times, or only to a point if it saves cost?
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Good question. The design is finalized and no changes can be made once the project is approved. Also, keep in mind space tech does not = Earth tech. Everything has to be hardened, designed to survive temperature extremes, and withstand intense radiation.
 
Red Squirrel said:
That was great, crazy to think it's finally in space now! Still a lot of steps to literally unfold but I feel the riskiest bit is probably over. There is still a chance for things to go wrong though so not quite out of the woods yet.
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so if things go wrong, how can they fix it?
There's no more space shuttle to park next to it for astronauts to work on it
 
JEDI said:
so if things go wrong, how can they fix it?
There's no more space shuttle to park next to it for astronauts to work on it
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They don't, as it isn't serviceable. It would just remain forever floating at L2 as a monument to American idiocy.

I just shake my head.

While I grant that Spitzer took some amazingly breathtaking images and showed just how much potential infrared space photography had, my high hopes for Webb are sort of dimmed by the huge cost versus its relatively short service life.

They spent ~$10 billion building the thing, which even if it works may not last more than 5 years (it only has enough coolant onboard to last for 5 years, but the engineers who built it "hope" they can stretch the coolant supplies out for around a 10 year service life. Not holding my breath there). Then, they design it to be non-serviceable and on top of that stick it somewhere where nobody can get to it if something goes wrong. The next follow-on, the Roman Space Telescope for 2027 also has a similar 5 year operational life and similar pricetag.

Sometimes, I think all space scientists need leashes and keepers capable of demonstrating actual common sense. The politicians writing the checks obviously have none.
 
Red Squirrel said:
That was great, crazy to think it's finally in space now! Still a lot of steps to literally unfold but I feel the riskiest bit is probably over. There is still a chance for things to go wrong though so not quite out of the woods yet.
Click to expand...

Ariane 5 is a reliable rocket, unfolding the mirror and sunshield will be by far the most nail biting part, nothing this complex has been done before.
 
Steltek said:
They don't, as it isn't serviceable. It would just remain forever floating at L2 as a monument to American idiocy.

I just shake my head.

While I grant that Spitzer took some amazingly breathtaking images and showed just how much potential infrared space photography had, my high hopes for Webb are sort of dimmed by the huge cost versus its relatively short service life.

They spent ~$10 billion building the thing, which even if it works may not last more than 5 years (it only has enough coolant onboard to last for 5 years, but the engineers who built it "hope" they can stretch the coolant supplies out for around a 10 year service life. Not holding my breath there). Then, they design it to be non-serviceable and on top of that stick it somewhere where nobody can get to it if something goes wrong. The next follow-on, the Roman Space Telescope for 2027 also has a similar 5 year operational life and similar pricetag.

Sometimes, I think all space scientists need leashes and keepers capable of demonstrating actual common sense. The politicians writing the checks obviously have none.
Click to expand...

It's pasively cooled. Anything else you want to pull out of your ass?

webbtelescope.org

Webb's Big Chill

Learn how and why NASA’s James Webb Space Telescope (JWST) scientific instruments are kept cold.
webbtelescope.org webbtelescope.org
 
imagine thinking that building an instrument to peer at the literal edges of the observable universe for five to ten years is idiocy. I’d hate to see what such a person considers intelligence. $10 billion is nothing considering the potential of this telescope, total drop in the bucket over the timescale of this project. Less than $100 per taxpayer very well spent.
 
Wait, only 5-10 year projected life span? Considering all the time and effort that went into it I would have figured it would have a much longer projected life.
 
Red Squirrel said:
Wait, only 5-10 year projected life span? Considering all the time and effort that went into it I would have figured it would have a much longer projected life.
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Like @Spacehead pointed out the problem is fuel. IIRC, the L2 Lagrange orbit isn't completely stable. So, rocket (h-peroxide, not sure) thrusts are needed to make minor corrections to the orbit.
Oh, look, NASA did this for me: https://solarsystem.nasa.gov/resources/754/what-is-a-lagrange-point/

Why not more propellant - not sure what the limiting factor was, size and mass do matter matter quite a bit when launching from earth.
 
Yeah figured it was stable and no longer needed fuel once in place, but guess no orbit is 100% stable. That particular orbit is also rather interesting the way it goes in a circle, but not necessarily around anything. Did not know such orbit was possible. I think I kinda get what's going on though, looking at the graphic.

I presume there is also a reason for putting it that far out, vs a geostationary orbit. Probably too many satellites and other stuff at those altitudes so it would get in the way when doing long exposures.
 
It’s an infrared telescope with incredible sensitivity. If it was in geostationary orbit it’d need separate (moving!) heat shields for the sun, earth, and moon. In L2 it only needs one permanently facing the sun and earth/moon system.

Five years is enough for it to do what it was designed to do. It’s not necessarily there just to make pretty pictures, it’s there to study the origin of the universe.
 
repoman0 said:
imagine thinking that building an instrument to peer at the literal edges of the observable universe for five to ten years is idiocy. I’d hate to see what such a person considers intelligence. $10 billion is nothing considering the potential of this telescope, total drop in the bucket over the timescale of this project. Less than $100 per taxpayer very well spent.
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I just wish they had made it serviceable by remote vehicle.
 
[DHT]Osiris said:
We'd need a remote vehicle to service it witbefore we could design it to be utilized by that remote vehicle.
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Not necessarily. Just have to design an interface a remote vehicle could attach to, and then design a remote vehicle that could attach to that interface at a later date.
 
Zorba said:
Not necessarily. Just have to design an interface a remote vehicle could attach to, and then design a remote vehicle that could attach to that interface at a later date.
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JWST wasn't designed with replaceable instruments. It does have a docking ring for future spacecraft to attach to it(not sure why) but trying to retro-fit non-replacable parts in space would be... difficult.

edit-
Old article from 2007
NASA Adds Docking Capability For Next Space Observatory
 
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