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James Webb Space Telescope emerges successfully from final thermal vacuum test
- ausbah 7y agoThis is so cool!
- de_watcher 7y agoAnd hot.
- mkoryak 7y agoHow many megapixels is this one?
- onion2k 7y agoThe complete array works out at 937 megapixels. (As of 2011. It may have changed.) http://optics.org/news/2/7/9 http://optics.org/news/2/7/9
- gjm11 7y agoThe main imager is the Near Infrared Camera. It has ten 2048x2048 sensors. They're configured in two kinda-independent groups with separate optics. Each group uses one of those sensors for longer wavelengths (so you get two lots of 2048x2048), and four of them for shorter wavelengths (so you get two lots of 4096x4096). The two modules can (and I guess usually will) be pointed at adjacent regions of the sky; I expect they'll overlap them a bit so you'll get slightly under 4096x2048 for the long wavelengths and slightly under 8192x4096 for the short. These are monochrome sensors but they have an array of filters they can swap in to measure different wavelengths. There are several other instruments, including some other imagers.
- maxxxxx 7y agoConsidering how much camera sensors have improved in the last few years I wonder how outdated these sensors are (or not) Edit: makes me also wonder if with all the delays they upgrade any equipment in the meantime.
- okket 7y agoHard to tell, since you can't use off-the-shelf sensors. They have to withstand the harsh environment in space, for a very long time, without any maintenance.
- 3JPLW 7y agoThey're also specifically designed to operate in absurdly low temperatures — one in fact requires temperatures under 7 Kelvin and so in addition to the sun shield there's a mechanical cooler. https://en.wikipedia.org/wiki/MIRI_(Mid-Infrared_Instrument) https://en.wikipedia.org/wiki/MIRI_(Mid-Infrared_Instrument)
- redisman 7y ago"Only" about 10 years. This has a very complicated orbit and needs to use fuel to adjust and stay on it.
- Datenstrom 7y agoI was working on an in space assembly project at NASA recently although it was in a research department so we were not concerned about using space rated equipment. We were exploring both traditional methods and reinforcement learning. The cameras we were using were 2048x2048 and I asked around about what we could expect to have available if it went to space and I think the best off the shelf space rated camera was about 720p so anything more would need to be custom.
- sandyrogers 7y agoI seem to remember the detector arrays for MIRI were built sometime between 2005 and 2009. (I worked on MIRI for a time in 2011)
- NikolaeVarius 7y agoMan, 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.
- d33 7y agoCould you elaborate on the complexity, comparing it to other complex science projects that succeeded? I'm a layman, curious if this is actually riskier than what humanity has done so far.
- robotixonic 7y agoI'm a layman too, and just watched this https://youtu.be/bTxLAGchWnA https://youtu.be/bTxLAGchWnA to better understand the complexity.
- enceladus_ice 7y agoI think a big amount of the complexity comes from the folded up sunshield. I remember it had torn during a test deployment last year. Here is a quick animation showing the whole deployment process: https://www.youtube.com/watch?v=vpVz3UrSsE4 https://www.youtube.com/watch?v=vpVz3UrSsE4
- nullwasamistake 7y agoIf it tears bad it's technically possible to send up a shield that floats near the telescope. There were some plans for that way back during the design phase if I remember right. Still wouldn't be cheap or easy
- mikepurvis 7y agoIt looks from the renders like the telescope has solar panels, antennas, etc on the sun/earth-side of the shield. Wouldn't sending a standalone shield screw that up as it would shade them?
- nn3 7y agoAt this price point it better be good. It has to make up for all the other astrophysics missions it killed with its (near) endless budget overruns.
- afpx 7y agoThat's a bit cynical. There are many examples of NASA missions that had far exceeded the original expectations.
- afpx 7y agoPlus, check out some of the engineering on this $10B masterpiece. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180003965.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/201800... In my opinion, much better for Human advancement than the typical $10B infrastructure project
- gameswithgo 7y agoindeed, I would take a bunch of 10billion scientific instruments over trillion dollar fighter jets or mid east military incursions any day.
- scrozart 7y agoYup. Hubble was no different; took forever and cost more than expected. These are novel scientific instruments, not helicopters.
- sandworm101 7y agoHubble'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 unannounced program and its budget is covering the development costs of that spying program. Given the testing scheduled I doubt this, but it remains a possibility.)
- leeoniya 7y ago> one step closer to its 2021 launch boy, that's gonna be a nail-biter. who's gonna insure that launch?
- NortySpock 7y agoNo one. Or, more accurately, the government self-insures most launches, and eats the cost of a failed launch.
- java-man 7y agowhat puzzles me all the time is why not build two instead. it looks like the R&D portion of the budget might be greater than the actual manufacturing cost, so building two would be less than 2x the price. if one launch fails, we've got a backup. if both launch, we have two instruments deployed. why don't we do it??
- icegreentea2 7y agoThe NASA-Congress decision making complex is kind of a monster. Often makes lot of penny wise, pound foolish decisions. (I should say ${X-Body}-Congress decision making complex is like that).
- mhb 7y agoIs there any economy of scale? Why not wait until the first one fails to build another one?
- java-man 7y agoI would expect the R&D costs to dominate. One does not even need to consider economy of scale. For example, if the R&D is $1 million, and manufacturing one mirror costs $100k, the total price for two mirrors is $1.2 million vs. $1.1 million for one. Plus, consider a non-zero probability of a launch failure.
- TeMPOraL 7y agoBecause that requires keeping all the specialized machinery and knowledge alive for the duration of the whole project. Given the length of this project, I wouldn't be surprised if at this point NASA couldn't order a second one built even if they wanted to. The unfortunate thing about advanced technology is that if you don't use it, you lose it. More specifically, you lose the research and machining setups and people with knowledge about them in their head; the main problem here being that documentation doesn't capture everything - a lot of tacit knowledge is captured in e.g. tuning of the machines, undocumented fixes made on-site, idiosyncrasies in manufacturing steps, etc.
- 7y ago
- sandworm101 7y agoObligatory xkcd: https://xkcd.com/2014/ https://xkcd.com/2014/ 2026? Probably not. 2021? I doubt it. My money is on 2023-24.
- zanny 7y agoThey already built the damn thing, how hard could it be to land it in stable orbit 1.5 gigameters from the planet? This ain't rocket science, people. Wait a second.
- drilldrive 7y agoIt is only rocket science if you use rockets. If you get the telescope up with a space elevator then the term no longer applies here.
- dzhiurgis 7y agoI had !remind me in 2 years setup for it. Didn't really know why, but figured out eventually by how long it's taking them. Also - isn't the tech behind it is going to be obsolete pretty soon?
- jbay808 7y agoObsolete in what sense?
- sandworm101 7y agoIt is a big digital camera. They dont stay cutting edge for very long.
- skizm 7y agoAnyone 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 been in the NYC area for a while now, and am used to seeing NYC salaries, but the pay is well below half of what I would make now and the cut seems too drastic even in a LCOL area. * I'm mostly talking about masters programs here.
- jcadam 7y agoJust 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 work in space, I'd go and get a MS (or higher) in aerospace engineering or space systems engineering and work at the systems level. I got out of aerospace and am much happier for it.
- mdorazio 7y agoTo 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.
- jcadam 7y agoOh, I admit there are good reasons for it. And there are people who prefer such a rigid, structured, and slow-paced environment. I ran into plenty while I was stuck doing that sort of work. Good for them. The world needs such people, probably in much greater numbers than it needs people like me -- if it needs people like me at all :)
- maxxxxx 7y ago