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Roger's Equations

This blog is all about science and technology (with occasional math thrown in for fun). The goal of this blog is to try and pass on the sense of excitement and wonder I feel when I read about these topics. I hope you enjoy the posts.
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The James Webb Space Telescope

Posted April 06, 2015 7:39 AM by Bayes

Hubble's Successor

Hello all! I've recently written an article for Engineering360 (News & Analysis Tab above) about the James Webb Space Telescope. It's a pretty incredible piece of engineering scheduled for launch in 2018. If you're interested, check it out here. If you already know a little about the JWST, you may want to jump ahead to the section of the article that details its specs called "The Precision." I've done a bit of research here (NASA has some great webpages devoted to it) and provide a lot of details I haven't seen on other articles on the JWST. Here's a little sample of the article:

The Precision (and Promise) of the James Webb Space Telescope

...To protect its heat-sensitive infrared detectors and mirrors, the JWST will be launched to the Sun-Earth second Lagrange point (L2) some 926,811 miles from Earth, a trip that will take roughly three months to complete. It will have a five-layer 40 ft x 60 ft sunshield to protect its mirrors and detectors from the Sun, Earth and Moon. This shielding is critical since all the JWST detectors and optics need to be kept below -370° F. One consequence is that the JWST will not be able to view the solar system inside of its L2 orbit.

The NASA Deep Space Network will be used to communicate with JWST. It will be designed to operate for five years with a goal of 10 years. Since manned spaceflight does not currently approach L2, there will be no opportunity for maintenance; whatever condition the JWST arrives in at L2 in will be the condition it stays in. Engineers working on the JWST must get it right the first time... Article found here

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Usbport
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Re: The James Webb Space Telescope

04/07/2015 12:26 PM

The downside of the JWST:

jwsts-latest-$1.5b-cost-overrun-imperils-other-high-priority-projects/

http://www.spacepolicyonline.com/news/gao-slams-jwst-msl-cost-overruns

http://aviationweek.com/awin/technical-cost-issues-persist-webb-telescope

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Rixter
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Re: The James Webb Space Telescope

04/07/2015 9:21 PM

The delays might mean better instruments when it gets deployed. Let's hope they get it right before they send it off to L2!

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Re: The James Webb Space Telescope

04/08/2015 12:22 AM

Yes, sometimes going slow lets you take advantage of parallel technical developments and improvements and gives you time to test thoroughly......only one chance.

That L2 spot already has some accumulated scrap and there are more L2 orbit projects planned beyond JWST (according to wikipedia)

I think they're planning a fuel depot and drive through take away as well....

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Re: The James Webb Space Telescope

04/08/2015 8:20 AM

That L2 spot already has some accumulated scrap and there are more L2 orbit projects planned beyond JWST (according to wikipedia)
What's the chance of a collision with other stuff, natural and man made, that's accumulated there?
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Re: The James Webb Space Telescope

04/08/2015 11:46 PM

I guess there is some risk....

I picture it more of a convenient spot to find a lost hubcap on your way to the next roadhouse.

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Re: The James Webb Space Telescope

04/08/2015 3:09 PM

Of course, but in the original proposal it was to be built with 'off the shelf' parts. Which is why it was supposed to be inexpensive and launched by 2010.

People get angry and complain about the dollars spent and the schedule slip when the military does the same thing with airplanes, e.g., the F-35. The F-35 was a completely new design to replace 3 aircraft and it is'only' 5X over the initial 2001 budget estimate; that almost makes it look good compared to the JWST which is nearly 18X over its initial budget estimate.

I'm not defending the F-35, just using it for comparison. As an astronomer, I am very concerned that the JWST is sucking up dollars and resources that were intended for other Astronomy projects that now may be facing cancellation.

(And yes, I know that The F-35 is a WAY more expensive program. We could buy 100+ JWSTs for the total money that will eventually be spent on the F-35 program.)

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