James Webb Space Telescope emerges successfully from final thermal vacuum test • Hacker News Board

Re: James Webb Space Telescope emerges successfully from final thermal vacuum test

#161

Post by DuskStar » Sat, Jun 01, 2019, 7:06 AM UTC

ethbro wrote: post #109

NikolaeVarius wrote: post #55

Earlier quoted context omitted.

I probably should have known this. I've read alot on Apollo, but never really internalized some of these facts.

People forget there was an entire series leading up to the Saturn V: https://en.wikipedia.org/wiki/Saturn_V#Saturn_development They've got a Saturn IB at an Alabama rest stop outside of Huntsville. Surprisingly small, but still towers above you!

> People forget there was an entire series leading up to the Saturn V

Well, sooorta. The Saturn V was the third in that series, after the Saturn I and Saturn IB. [0] While there were proposed intermediate Saturns (and ones past V, too) only two first stages were developed, and the V was the only launcher to fly with the F-1 engine.

0: https://en.wikipedia.org/wiki/Saturn_(rocket_family)

Re: James Webb Space Telescope emerges successfully from final thermal vacuum test

#162

Post by kpU8efre7r » Sat, Jun 01, 2019, 12:46 PM UTC

NikolaeVarius wrote: post #7

Man, I really want this telescope to succeed its mission, but I just can't get over how complex its deployment procedure is. I am extremely pessimistic about it actually managing to deploy as planned.

I'm incredibly nervous as well. If a second telescope had to be built for whatever reason would it take as long and cost as much as the first? Or is all the cost and time due to R+D?

Re: James Webb Space Telescope emerges successfully from final thermal vacuum test

#163

Post by [deleted] » Sat, Jun 01, 2019, 4:06 PM UTC

mdorazio wrote: post #38

jcadam wrote: post #37

Earlier quoted context omitted.

Just a bit of warning: Software Engineering in Aerospace is NOT fun. You're basically in a supporting role to the hardware and system engineers designing the spacecraft. It's pure drudgery... process to the point of absurdity, specs and tasks being spoon fed to you with little room for creativity and/or problem solving, etc. The pay, benefits, and level of respect on the job reflect all of that. If you really want to…

To be fair, the reason for this is that if you try to be creative and don't follow strict processes, things fail a million miles from Earth or blow up entirely.

[deleted]

Re: James Webb Space Telescope emerges successfully from final thermal vacuum test

#164

Post by locknumber110 » Sat, Jun 01, 2019, 4:26 PM UTC

sandworm101 wrote: post #28

scrozart wrote: post #23

Earlier quoted context omitted.

Yup. Hubble was no different; took forever and cost more than expected. These are novel scientific instruments, not helicopters.

Hubble's cost structure is complicated. It is essentially a modified spy satellite and so much of its development costs were shrouded. We don't know how much was saved, or how much of Hubble's public budget was used on other projects. JWST is different. It is a unique object with no equivalent. Its cost structure is therefore not comparable to Hubble. (Or I am wrong. Maybe JWST is a modified version of a super-secret…

I think it's fair to say that JWST isn't just a tweaked KH like Hubble. The mirrors and sensors in JWST are completely optimized for infrared, which is a borderline-useless part of the spectrum for high-res terrestrial surveillance. Optical scopes also wouldn't need the extensive sunshield and cooling systems that JWST will. By the time that a theoretical secret optical JWST-KH were retrofitted with new mirror designs, new sensors, and new active and passive cooling systems for a public infrared science mission, you basically have a completely redesigned satellite.

Re: James Webb Space Telescope emerges successfully from final thermal vacuum test

#165

Post by GlenTheMachine » Sat, Jun 01, 2019, 11:19 PM UTC

Buttons840 wrote: post #154

ethbro wrote: post #103

Earlier quoted context omitted.

"What do we do when the robotic satellite fails?" "Send another robot!"

"What do we do when the L2 point is filled with broken robots?" Could that happen?

Unclear. L2 is an unstable Lagrange point, so the robots wouldn't just stay put. But that doesn't mean they would leave, either, necessarily. They could end up in funky Lissajous orbits and go flying through L2 regularly.

The orbital mechanics around Lagrange points are weird.