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

#41

Post by petschge » Fri, May 31, 2019, 2:12 PM UTC

NikolaeVarius wrote: post #21

FrojoS wrote: post #15

Earlier quoted context omitted.

This video explains it very well. https://www.youtube.com/watch?v=k8yRDrl76d0 Half way through the video, I understood why it's so expensive and risky. On the other hand, Apollo 11 had many 'firsts' that couldn't be tested before the actual mission and it worked out 'first shot'. Of course there were some problems and Apollo 13 showed that the odd's where not too good.

Huge difference is that Apollo had highly trained human beings on board to fix things that could not be planned for. There were also 10 previous missions to Apollo 11 to work out the kinks, with one failing with loss of life. JW is not designed to be fixed or fail, nor are there training runs. It HAS to work first shot.

Regarding the 10 missions before Apollo 11: It's a little more complicated. Apollo 1 is the name that was given to honor the astronauts who died in the pad accident. Apollo 2 and 3 didn't exists. But a whole bunch of other tests did exist testing Saturn 5 before we got to the unmanned Apollo 4, 5 and 6 tests. And starting with Apollo 7 humans were included. See https://en.wikipedia.org/wiki/List_of_Apollo_missions for details.

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

#42

Post by batbomb » Fri, May 31, 2019, 2:13 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.

Normally they name telescopes once they are on orbit and working, because they don’t want to put a name on something and have it fail.

The joke with JWST is that it’s not allowed to fail.

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

#43

Post by NikolaeVarius » Fri, May 31, 2019, 2:14 PM UTC

jcadam wrote: post #37

skizm wrote: post #34

Anyone know if there are any well paying jobs in space programs of any kind? I've been seeing a growing number of reputable universities offering a wider range of space / aerospace / engineering offerings* and I've been getting curious what's out there. Only issue is, a lot of places I looked pay well below market rates :/ (at least for software engineers). I'll admit my expectations might be off considering I've bee…

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…

I have to agree with this. Tons of extremely smart people, but day to day was hell in the software side.

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

#44

Post by petschge » Fri, May 31, 2019, 2:14 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…

Part of the cost of Hubble was that the teams working on the keyhole satellites was not allowed to tell the Hubble designers about "lessons learned" and the Hubble team had to find them out the hard way.

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

#45

Post by NikolaeVarius » Fri, May 31, 2019, 2:15 PM UTC

Klathmon wrote: post #32

knd775 wrote: post #19

Earlier quoted context omitted.

And this isn't like hubble, where we could (and did) send up a space shuttle to fix an issue after launch. Really scary.

To be a bit more specific, we can't send something up to fix this because it's magnitudes further away from the earth than Hubble is. JWT will be ~1.5 million km away from earth, in a special orbit around a spot called the "L2 Lagrange point". It's located there so that it can kind of hide in the earth's shadow at pretty much all times and keep all the nearby "bright" things behind the heat shield. For comparison, th…

We also can't fix this, because it was designed to be unfixable. Making it fixable would counter productively make the design more complex.

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

#46

Post by lostmyoldone » Fri, May 31, 2019, 2:15 PM UTC

escapecharacter wrote: post #39

Klathmon wrote: post #32

Earlier quoted context omitted.

To be a bit more specific, we can't send something up to fix this because it's magnitudes further away from the earth than Hubble is. JWT will be ~1.5 million km away from earth, in a special orbit around a spot called the "L2 Lagrange point". It's located there so that it can kind of hide in the earth's shadow at pretty much all times and keep all the nearby "bright" things behind the heat shield. For comparison, th…

I mean, the giddy idiot in me just gets excited about the urgent need for a human L2 mission to fix it.

Likewise. My train of thought goes like

"So what if it fails? There's a lot of money sunk into that! Well, maybe someone would actually decide it's worth going to the L2 to fix it, wouldn't that be cool!!"

So yeah, not the only idiot...

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

#47

Post by [deleted] » Fri, May 31, 2019, 2:15 PM UTC

escapecharacter wrote: post #39

Klathmon wrote: post #32

Earlier quoted context omitted.

To be a bit more specific, we can't send something up to fix this because it's magnitudes further away from the earth than Hubble is. JWT will be ~1.5 million km away from earth, in a special orbit around a spot called the "L2 Lagrange point". It's located there so that it can kind of hide in the earth's shadow at pretty much all times and keep all the nearby "bright" things behind the heat shield. For comparison, th…

I mean, the giddy idiot in me just gets excited about the urgent need for a human L2 mission to fix it.

[deleted]

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

#48

Post by [deleted] » Fri, May 31, 2019, 2:19 PM UTC

NikolaeVarius wrote: post #45

Klathmon wrote: post #32

Earlier quoted context omitted.

To be a bit more specific, we can't send something up to fix this because it's magnitudes further away from the earth than Hubble is. JWT will be ~1.5 million km away from earth, in a special orbit around a spot called the "L2 Lagrange point". It's located there so that it can kind of hide in the earth's shadow at pretty much all times and keep all the nearby "bright" things behind the heat shield. For comparison, th…

We also can't fix this, because it was designed to be unfixable. Making it fixable would counter productively make the design more complex.

[deleted]

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

#49

Post by sanxiyn » Fri, May 31, 2019, 2:25 PM UTC

NikolaeVarius wrote: post #21

FrojoS wrote: post #15

Earlier quoted context omitted.

This video explains it very well. https://www.youtube.com/watch?v=k8yRDrl76d0 Half way through the video, I understood why it's so expensive and risky. On the other hand, Apollo 11 had many 'firsts' that couldn't be tested before the actual mission and it worked out 'first shot'. Of course there were some problems and Apollo 13 showed that the odd's where not too good.

Huge difference is that Apollo had highly trained human beings on board to fix things that could not be planned for. There were also 10 previous missions to Apollo 11 to work out the kinks, with one failing with loss of life. JW is not designed to be fixed or fail, nor are there training runs. It HAS to work first shot.

Apollo is probably the wrong thing to compare with, but sky crane did work first shot.

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

#50

Post by jvanderbot » Fri, May 31, 2019, 2:25 PM UTC

skizm wrote: post #34

Anyone know if there are any well paying jobs in space programs of any kind? I've been seeing a growing number of reputable universities offering a wider range of space / aerospace / engineering offerings* and I've been getting curious what's out there. Only issue is, a lot of places I looked pay well below market rates :/ (at least for software engineers). I'll admit my expectations might be off considering I've bee…

I'm betting that in 5-10 years, there will be an explosion of aero startups. But fast and loose don't work as well in space, where everything ends up going 11,000 meters per second at least. The culture will necessarily be a bit more conservative, and as others have mentioned, software is usually a supporting element at best, a necessary evil at worst.