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James Webb is fully deployed

nasa.gov

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Re: James Webb is fully deployed

#291

Post by 14 »

behnamoh wrote: post #285
JohnBooty wrote: post #208

Earlier quoted context omitted.

Great blog post from NASA themselves explaining it: https://blogs.nasa.gov/webb/2022/01/06/why-doesnt-webb-have-... the post is really not very long and I would suggest getting it straight from the horse's mouth, but for those not willing to devote a click here are arguably the most relevant bits! "deployment surveillance cameras would not add significant information of value for engineering teams commanding the spac…

they could have sent a temporary camera along with the craft to take a picture of it at the final position and send back to earth.

How about a Tesla with Sentry cameras going?

Re: James Webb is fully deployed

#292

Post by newaccount2021 »

behnamoh wrote: post #285
JohnBooty wrote: post #208

Earlier quoted context omitted.

Great blog post from NASA themselves explaining it: https://blogs.nasa.gov/webb/2022/01/06/why-doesnt-webb-have-... the post is really not very long and I would suggest getting it straight from the horse's mouth, but for those not willing to devote a click here are arguably the most relevant bits! "deployment surveillance cameras would not add significant information of value for engineering teams commanding the spac…

they could have sent a temporary camera along with the craft to take a picture of it at the final position and send back to earth.

No post body was provided.

Re: James Webb is fully deployed

#294

Post by terramex »

dylan604 wrote: post #66
fotta wrote: post #13

Earlier quoted context omitted.

It'll take a few weeks after L2 insertion to cool the components and another 5 months to calibrate the instruments.

I'm hoping that the 5 months of calibration time is one of those where the engineers were asked "how long", so they thought about it and then padded the shit out of it, then the PMs took that number and padded it yet again. After all that, it only takes a few weeks. It'll be the first milestone JWST would meet early, so not too likely. We've only waited decades, so a few more months isn't that bad. At least it is off…

> Some high priority scientific observations (GTO & GO) with the JWST are likely to be carried out during the commissioning period, since it is clearly desirable to begin to take science data as early as is technically feasible.

> Early Release Observations (EROs) will be taken by JWST during both the commissioning and post-commissioning phases of operation. These observations will be chosen to have wide public appeal and are designed to demonstrate the capabilities of the JWST instruments. Publication or reporting in any form of results of these observations is embargoed until the EROs are released.

https://jwst-docs.stsci.edu/jwst-opportunities-and-policies/...

There is a chance for first images to be released before commissioning is complete.

Re: James Webb is fully deployed

#295

Post by mr_toad »

jsharpe wrote: post #228
surfsvammel wrote: post #209

Earlier quoted context omitted.

Won't it be pretty close to earth in its final position at L2? If so, is there no chance that there will be future missions to do service to it? If so, maybe we can get a photo of if then?

It's not that close. The moon is 384,400km away, and JWST will be 1.5 million km away (i.e., around 4x as far as the moon). It would be a pretty serious undertaking to get to it and get back.

Distance isn’t the best proxy for difficulty of a space mission. The delta-v to get to low lunar orbit is higher than the delta-v to get to L2. The delta-v required for lunar landing is considerably higher. And all of these manoeuvres are much less than the delta-v required to get to LEO.

Re: James Webb is fully deployed

#296

Post by sailingparrot »

bmitc wrote: post #101
dgrin91 wrote: post #23

One of the big numbers that been thrown around is that JWST has 344 single points of failure in its mission. Now that deployment has been completed, is there somewhere that lists how many of those points we have passed?

Can anyone elaborate on these single points of failures? For example, are they actually single points of failure? Or is it a bit of exaggeration for marketing purposes (a bit of under promise, over deliver)?

A lot of them are "optional" but strongly preferred. E.g. if one or two of the mirror wings failed to deploy, JWST would still be usable, but with a degraded resolution.

If one or two layers of the sunshade failed to correctly deploy, JWST is still usable, but the temperature of the mirrors would be higher than expected, and thus the spectrum of IR light it can image would be reduced.

If the momentum flap fails to deploy, then more fuel is needed to keep the JWST at the right attitude/position, shortening the lifespan of the mission.

But some others were make or break: deployment of the solar panels, deployment of the secondary mirror and a few others. If those had failed then the mission would be over.

Re: James Webb is fully deployed

#297

Post by micromacrofoot »

MegaDeKay wrote: post #178
micromacrofoot wrote: post #16

Earlier quoted context omitted.

One of the more interesting things that we'll get is data about what's in the atmosphere of exoplanets https://jwst.nasa.gov/content/science/origins.html Note that the next 5 months or so will consist of mirror cooling and calibration, so nothing until summer.

Would you happen to know if they can make intermediate observations while this is in process e.g. observe a relatively nearby object before the telescope is fully cooled and aligned? I'm wondering if they would be able to prove out the optics early on - this is no slam dunk as the Hubble proved.

Not really… these telescopes aren’t like snapping a photo, they take long exposures. The famous hubble deep field image was a 20+ day exposure time spread out over months (due to orbits, etc).

Trying to get an image out of it too early would just be a mess, it’s kind of an all or nothing affair. The sensor needs to be at the right temperature and the mirrors need to be precisely aligned. It’s all built to be outrageously sensitive so it can operate at the level it’s meant to.

Also, each image it’s scheduled to take has been submitted years in advance.

Re: James Webb is fully deployed

#298

Post by ThinkBeat »

porsupah wrote: post #281
ThinkBeat wrote: post #189

Earlier quoted context omitted.

They should have made a port for refueling it. An internal fuel tank and a high-capacity tank externally Once the fuel is getting low, launch a refuel. when the new supply gets closed, eject the previous tank, dock the new one. Easy. When they managed to du an in air refuel of a SR71 in 1970s . Surely we can dock a fuel tank in 2022?

They did: "Unlike Hubble, Webb isn't designed to be fixed by astronauts. But it can be refueled robotically. Zurbuchen says that 'once this telescope is deployed, I'm going to put all the effort towards developing that technology, and so within the 10-year lifespan, we can go refuel it'" https://nitter.42l.fr/marinakoren/status/1474367236244750345... https://nitter.42l.fr/Dr_ThomasZ/status/1474398711505580032#...

awesome :) Thank you.

Re: James Webb is fully deployed

#299

Post by sandworm101 »

jazzyjackson wrote: post #263
amelius wrote: post #241

Earlier quoted context omitted.

Perhaps one day they could send a robot mechanic along with the mission, and then a camera could be of value.

I’m sure if we ever have sufficient technology to build a city on the moon, the first museum exhibit will be a captured JWST

No. The museum will be built atop its first exibit: tranquility base. See Futurama s01e02.

Re: James Webb is fully deployed

#300

Post by micromacrofoot »

q1w2 wrote: post #57
micromacrofoot wrote: post #16

Earlier quoted context omitted.

One of the more interesting things that we'll get is data about what's in the atmosphere of exoplanets https://jwst.nasa.gov/content/science/origins.html Note that the next 5 months or so will consist of mirror cooling and calibration, so nothing until summer.

This will only work for a handful of very nearby exoplanets, unfortunately.

hell I’d be excited for 1!
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