James Webb Space Telescope

[Voyager275]

Are you excited for this? I cant wait till it allows us to see the atmospheres of worlds within 20 parsecs.

[Dkmdlb]

it allows us to see the atmospheres of worlds within 20 parsecs.

Source? That seems suspect.

[Streetwind]

I'm excited, but 2018-2019 is a looong time away still

I believe this is going to be the most expensive single object NASA has ever put into space? $9 billion and counting for one satellite, and it's not even assembled yet.

Just shows how much trust they're showing Arianespace by ordering an Ariane 5 ECA instead of doing it on US vehicles... but then again, that is currently the world's most reliable heavy lifter.

[Nibb31]

I'm excited, but 2018-2019 is a looong time away still

Not on the geological scale.

Not even on the scale of the project. It was started in 1996, nearly 20 years ago already. Another couple of years is a drop in the bucket.

[LordFerret]

Source? That seems suspect.

Google is your friend.

http://www.jwst.nasa.gov/

[Hcube]

Just shows how much trust they're showing Arianespace by ordering an Ariane 5 ECA instead of doing it on US vehicles... but then again, that is currently the world's most reliable heavy lifter.

Yeah ariane 5 is amazing even though its rapidly becoming obsolete... Hopefully ariane 6 will be even more safe, because with spacex's prices, safety is pretry much going to be arianespace's last advantage...

(and the Kourou launch site is the best btw)

just wondering,what kind if telescope is james webb? i mean, will it analyse visible light, infrared, radiowaves?

Will Hubble be retired immediatley after Webb is operational or have they still different purposes that justify the cost of operating both telescopes?

[Streetwind]

JWST is a near infrared telescope. Means it loses the extreme versatility of Hubble (which can image pretty much any wavelength you ask it to... or could, before its instruments started breaking). But it is extremely good at near infrared. And it's the frequency that's best for peering deep into the early universe, which is its main purpose.

Hubble will be retired when its orbit decays to the point of becoming dangerously close to uncontrolled reentry (Hubble is in LEO, in contrast to JWST, which will go to a lagrange point). It will then spend the last puff of fuel that it has to make a controlled reentry over the ocean. Current estimates expect this to happen around 2020.

[Fuzzy Dunlop]

Just shows how much trust they're showing Arianespace by ordering an Ariane 5 ECA instead of doing it on US vehicles... but then again, that is currently the world's most reliable heavy lifter.

My theory is that NASA chose Ariane specifically because they're not american. This way if (god forbid) there is a launch failure NASA can blame it on those "darned incompetent europeans!" (while ESA can say "Oh well, we weren't the ones that payed for that $9 billion firework show!").

[Streetwind]

The reality is much more benign... the launch vehicle is an ESA partner contribution to the project

[_Augustus_]

My theory is that NASA chose Ariane specifically because they're not american. This way if (god forbid) there is a launch failure NASA can blame it on those "darned incompetent europeans!" (while ESA can say "Oh well, we weren't the ones that payed for that $9 billion firework show!").

Good point.

I also think it's because of the utter lack of things that the Ariane 5 currently launches. It's capable of launching a Voyager-level space probe, a mini shuttle, and the ATV, but it's typically used for little satellites.

What a waste.

[basic.syntax]

I'm excited that it was saved, I recall a budget cuts period when it was nearly grounded.

[Bill Phil]

ISS is the most expensive thing in space...

But JWST ( named after a NASA admin) isn't a Hubble replacement. It's a different type for a different mission.

[maccollo]

ISS is the most expensive thing in space...

But will it be the most expensive single payload ever launched?

[Kryten]

Do we have a cost for Polyus/Skif? It certainly did not look cheap.

[Camacha]

Not on the geological scale.

Not even on the scale of the project. It was started in 1996, nearly 20 years ago already. Another couple of years is a drop in the bucket.

It is on the I need to go to the bathroom and have to wait this long scale

[Hcube]

I also think it's because of the utter lack of things that the Ariane 5 currently launches. It's capable of launching a Voyager-level space probe, a mini shuttle, and the ATV, but it's typically used for little satellites.

What a waste.

It's not a waste : those small-medium size satellites are launched in groups of 2 (maybe more) so that the flight is not a waste of money ! When you think about it why would someone ever buy an Ariane 5 launch for a light payload ? The way around is to share the launch with another payload

And the rest of the time it lifts bus-sized satellites

There is no such thing as "overbuilding" in rocket science/industry !

For the little satellites there's always Vega

[Tommygun]

There is no such thing as "overbuilding" in rocket science/industry !

I'm not sure, the SLS is quite big for NASA's current budget.

[Streetwind]

NASA's budget is fine, they get more money than the combined total of all civillian space programs in the rest of the world (including Russia, China, Europe, India...). They're simply ordered to spend it in the most inefficient manner possible. The purpose of NASA's budget is not to build the SLS, it is to maintain jobs and infrastructure which keeps the responsible congressmen in congress.

Were NASA able to freely allocate their budget in whatever way they pleased, choose their own industry suppliers and employ only those people they truly needed, SLS would be on the pad already with actual missions planned out even if NASA's budget was cut clean in half... or, even more likely, SLS would not exist and we'd instead have a commercial rocketry development program ten times the current funding volume.

But that's not the topic of this thread, is it? Let's return to talking about the James Webb Space Telescope.

Here's a recent article with a cool opening image of the spacecraft looking a wee bit like an imperial star destroyer

Edited April 8, 2015 by Streetwind

[Wallygator]

So it goes up in October 2018 and shuts down sometime between 2023 and 2028 - depending on supply and reliability. Not too bad. A decade of peering into the past.

I assume that the 9 billion probably includes the ground operations, etc. during that time. Further extension would likely be only achievable if more funding was applied since its not likely resupply missions would or could occur.

And since the age of the universe is about 13.8, that's less than a dollar per year. Nice.

[Streetwind]

I assume that the 9 billion probably includes the ground operations, etc. during that time.

Mostly.

$800 million out of the $9 billion total cost is set aside for five years of operation after deployment. Additional operation time, if possible, will require additional funding.

[TythosEternal]

...and since the age of the universe is about 13.8, that's less than a dollar per year. Nice.

This is the best rationalization for JWST resource planning issues I've seen yet.

[Bill Phil]

Let's just hope that it doesn't suffer what Hubble did.

I severely doubt it will, though...

[Tommygun]

Let's just hope that it doesn't suffer what Hubble did.

I severely doubt it will, though...

Well maybe we will get an actual mission for Orion and the SLS then.

[PB666]

Since many threads have post suggesting that JA Webb Space Telescope is a replacement for Hubble ....

This is the other reason that Webb is not a replacement for Hubble is that its capabilities are not identical. Webb will primarily look at the Universe in the infrared, while Hubble studies it primarily at optical and ultraviolet wavelengths (though it has some infrared capability). Webb also has a much bigger mirror than Hubble. This larger light collecting area means that Webb can peer farther back into time than Hubble is capable of doing. Hubble is in a very close orbit around the earth, while Webb will be 1.5 million kilometers (km) away at the second Lagrange (L2) point.

http://jwst.nasa.gov/comparison_about.html

This telescope will require 47'K heat removal for is near infrared detctor and a 2 stage colling system for the mid-range infrared detector, 7'K. Both can operate above optimal but doing this results in two corrections. The noise to signal will increase. Sampling times will inrease but not indefinitely, so that at some point data will have to be stacked by the computers and statistially analyzed and filtered later. This means you would have to have a large computer with lots more memory and heat producion, or crop the sampled dat to smaller regions. Grab, crop and toss.

If this equipment needs service Nasa better have a manned space program capable of reaching L2. We will see just how effective the unmanned space program will be, I give Webb 5 years befor some major crppling error occurs.

[Streetwind]

If this equipment needs service Nasa better have a manned space program capable of reaching L2. We will see just how effective the unmanned space program will be, I give Webb 5 years befor some major crppling error occurs.

JWST is not designed to be servicable IIRC. It's a one-shot. Though it may be repurposed after its coolant runs out, like WISE is for example.

If I am wrong, please do correct me