James Webb Telescope

Segnosaur said:
Anyone know why it is being launched from French Guiana and not from KSC? (I know that there is European involvement in the project, but since the telescope was assembled in California, transporting it overseas seems like an unnecessary risk/expense.)

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The ESA offered to launch the telescope in exchange for time using the telescope.
 
Segnosaur said:
Anyone know why it is being launched from French Guiana and not from KSC? (I know that there is European involvement in the project, but since the telescope was assembled in California, transporting it overseas seems like an unnecessary risk/expense.)

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One factor is that French Guiana is closer to the equator, getting more use from the Earth's rotational speed.
 
Pope130 said:
One factor is that French Guiana is closer to the equator, getting more use from the Earth's rotational speed.
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That's not much of a gain even for things headed toward equatorial GEO. Won't that gain come at the cost of having to change the orbital plane later? Not sure what the exact demands are of the final orbit.
 
There's also the issue that the contracts have been signed for ages. It could have gone up on a SpaceX Falcon Heavy, but instead it's going up on an older Ariane.
 
arthwollipot said:
There can't be more than one reason? When was that deal negotiated? I'll bet it was years ago.
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To expand on that a bit, I think it's because not all rockets are capable of carrying this kind of payload to the destination. It isn't going to LEO, like the Hubble, but to a Lagrange point which is much farther out in space.

The Europeans had a rocket that could do it at a time when the Americans did not.
 
jadebox said:
Again, the reason the telescope is being launched on an Ariane is that NASA negotiated a deal in exchange for observation time using the telescope.
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OK. Why did you feel the need to repeat that? Are we missing something?

You seem to be implying that because they charged a price for the service that there wasn't a reason we chose their service, which doesn't really make sense.
 
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Again, the reason the telescope is being launched on an Ariane is that NASA negotiated a deal in exchange for observation time using the telescope.
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That makes sense from a financial perspective. (Share the cost/share the benefit). But, they could have also negotiated a deal that said "We'll pay SpaceX/NASA/etc. to launch in exchange for observation time"
To expand on that a bit, I think it's because not all rockets are capable of carrying this kind of payload to the destination. It isn't going to LEO, like the Hubble, but to a Lagrange point which is much farther out in space.

The Europeans had a rocket that could do it at a time when the Americans did not.
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This also makes sense. (I'm surprised that the Americans didn't have any sort of heavy-lift capability at the time, but I guess that sort of thing happens.)

But then, there is still the question: Why launch from French Guiana, instead of launching the European rocket from Kennedy Space Center. (Note: My concern is mostly about the risk of transporting the telescope overseas. Even if the risks may be minimal, the telescope was a huge investment in resources. If it were me I would want to eliminate anything that could jeopardize it.)
 
Segnosaur said:
But then, there is still the question: Why launch from French Guiana, instead of launching the European rocket from Kennedy Space Center.
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Pretty sure rockets can't be moved around that easily. KSC wouldn't be equipped to launch an Ariane.
 
According to Wikipedia, the parameters of this agreement seem to have been agreed to all the way back in 2007.

https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Partnership

NASA, ESA and CSA have collaborated on the telescope since 1996. ESA's participation in construction and launch was approved by its members in 2003 and an agreement was signed between ESA and NASA in 2007. In exchange for full partnership, representation and access to the observatory for its astronomers, ESA is providing the NIRSpec instrument, the Optical Bench Assembly of the MIRI instrument, an Ariane 5 ECA launcher, and manpower to support operations.[78][124] The CSA will provide the Fine Guidance Sensor and the Near-Infrared Imager Slitless Spectrograph plus manpower to support operations.[125]
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But then, there is still the question: Why launch from French Guiana, instead of launching the European rocket from Kennedy Space Center. (Note: My concern is mostly about the risk of transporting the telescope overseas. Even if the risks may be minimal, the telescope was a huge investment in resources. If it were me I would want to eliminate anything that could jeopardize it.)
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Wouldn't it be even more difficult and possibly risky to transport the European rocket to Kennedy Space Center? Just BTW, if the plan was set in stone back in 2007, there may have been other considerations at the time. It was probably seen as the most viable available rocket vehicle at the time which met all of the requirements.
 
RecoveringYuppy said:
You seem to be implying that because they charged a price for the service that there wasn't a reason we chose their service, which doesn't really make sense.
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Huh?

The main reason that the ESA is launching the telescope is that they agreed to do so in exchange for observation time using the telescope. ULA could have launched it using an Atlas or Delta rocket, but they would have charged NASA for the launch. SpaceX wasn't an option when the launch was negotiated.
 
Segnosaur said:
Anyone know why it is being launched from French Guiana and not from KSC?
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Since it's going up on a European Space Agency rocket, why would it launch from a NASA facility instead of from a European Space Agency facility? I imagine that an orbital rocket launch requires a fair amount of ground support specific to the kind of rocket you're launching. I doubt KSC has that stuff already for an Ariane rocket, whereas Arianes launch from the Guiana Space Center all the time. Importing that equipment to KSC for one launch likely doesn't make any sense.
 
Now I want a documentary on the transport cradle(s) for the scope and its major subassemblies. The engineering on that thing must be super intense. Especially if they're confident it can keep the scope safe during a voyage through the entire range of possible Atlantic weather.
 
theprestige said:
Now I want a documentary on the transport cradle(s) for the scope and its major subassemblies. The engineering on that thing must be super intense. Especially if they're confident it can keep the scope safe during a voyage through the entire range of possible Atlantic weather.
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I doubt it's going to have more stress on it during transport to the launch facility than it will have during launch. But yes, engineering a complex satellite to withstand launch forces is a very non-trivial endeavor. It isn't just about the g-forces of launch either, there can also be quite a bit of vibration.
 
Forgive my ignorance. And this is probably in the thread somewhere.

How long does it take to get on station and then start working? When can we expect pictures of little green men?
 
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