James Webb Space Telescope, information, updates and discussion |
James Webb Space Telescope, information, updates and discussion |
Dec 30 2021, 02:18 AM
Post
#121
|
|
Senior Member Group: Members Posts: 2082 Joined: 13-February 10 From: Ontario Member No.: 5221 |
IIRC, the was a recent test which involved a "reuse" engine was able to grab the engine bell of an existing satellite that was almost out of propellant, latch on, and provide another "X years" of service. Yes, this one: https://en.wikipedia.org/wiki/Intelsat_901 Since engine bells are on practically every satellite, and they are usually of the same overall shape, they are the best way to hook onto something that was not designed to be serviced. Since JWST is in that (large!) category, I expect that a servicing mission would mostly do that (assuming the instruments are still good in 2035, or whenever). And a photo of JWST fully deployed would be pretty awesome, of course |
|
|
Dec 30 2021, 03:30 AM
Post
#122
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
JWST's mirror and instruments will be in the dark, so there should never be a photo of them.
Project scientist John Mather said, "In-space refueling of #JWST? Logically possible but difficult." I would presume that this will not occur. |
|
|
Dec 30 2021, 04:47 AM
Post
#123
|
|
Senior Member Group: Members Posts: 2082 Joined: 13-February 10 From: Ontario Member No.: 5221 |
In the case of Intelsat, it was just attached and used its own thrusters to push the satellite where needed. No need to open anything up. Though I digress, this is is all strictly academic, and hopefully will remain so for a very long time to come!
|
|
|
Dec 30 2021, 05:41 AM
Post
#124
|
|
Member Group: Members Posts: 238 Joined: 28-October 12 Member No.: 6732 |
|
|
|
Dec 30 2021, 09:35 AM
Post
#125
|
|
Junior Member Group: Members Posts: 43 Joined: 13-June 08 Member No.: 4206 |
Pretty sure I recall a NASA official saying they would not even think about a robotic refueling mission till the telescope was on-station and operational and proving its worth. Then they would begin work. Might have been Zurbuchen.
Whether it would be a robotic arm uncapping the gas tanks, or clip-on module, or something else, wasn't said. Since this is likely 10-15 years out, there's plenty of time to develop and refine the technicals. |
|
|
Dec 30 2021, 01:52 PM
Post
#126
|
|
Member Group: Members Posts: 154 Joined: 21-April 05 From: Rochester, New York, USA Member No.: 336 |
The manufacture of the JWST mirror blanks has now been completed. Despite this milestone, the fate of JWST is still somewhat precarious, because although the scientific bang from the telescope is expected to be huge, the bucks required have increased to a staggering $4.5 billion. A Space.com article on the squeeze in NASA's space-based astronomy plans gives some background. The JWST home page can be found here. The Space Telescope Science Institute, which runs Hubble, also has a site here. As does ESA. Fun looking at this 16 years later... |
|
|
Dec 30 2021, 04:06 PM
Post
#127
|
|
Member Group: Members Posts: 808 Joined: 10-October 06 From: Maynard Mass USA Member No.: 1241 |
... is there an engineering camera that can return "unfolding images" ... it seems that for $10,000,000,000 they could put one 1024x1024 camera on JWST --- and test out the radio and such -- You could always shut it down when unfolded...
-------------------- CLA CLL
|
|
|
Dec 30 2021, 04:18 PM
Post
#128
|
|
Member Group: Members Posts: 191 Joined: 20-November 06 From: Saint Louis Member No.: 1376 |
... is there an engineering camera that can return "unfolding images" ... it seems that for $10,000,000,000 they could put one 1024x1024 camera on JWST --- and test out the radio and such -- You could always shut it down when unfolded... I'm sure we would have seen those images. Good PR. I also remember them saying on the launch livestream that the solar panel deploy would be the last time anyone would ever lay eyes on JWST. Of all the spacecraft we've launched, this is the one that would be the most satisfying to see after it fully deploys. -------------------- - Matt
|
|
|
Dec 30 2021, 04:40 PM
Post
#129
|
|
Member Group: Members Posts: 684 Joined: 24-July 15 Member No.: 7619 |
... is there an engineering camera that can return "unfolding images" ... it seems that for $10,000,000,000 they could put one 1024x1024 camera on JWST --- and test out the radio and such Well, that's a compromise you make when you realize that launches to orbit cost IIRC, their weight in gold, (while Mars / outer solar system cost their weight in diamonds) Once somebody figures out how to do an integrated thin-film mylar solar array / 20 megapixel camera chip, we might get some interesting deployment videos. Did anybody ELSE have a "WOW" moment when Breakthrough-Starshot mentioned that they were looking imprinting a hologram of a light stable sail onto a flat surface? TANGENT - Could a James Webb v 2.0 "cheat" by imprinting a hologram of a 40m scope onto bigger mylar sail? |
|
|
Dec 30 2021, 05:58 PM
Post
#130
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
Once the sunshield is partially unfolded, the rest of JWST will be in the dark for the remainder of its mission and they don't want sunlight on it, even now. Any sunlight on the mechanisms now is just a delay before the long passive cooling process will complete.
If you want to picture JWST during its mission, picture the night side of an atmosphere-less world. That's what it's going to look like: black on black. For reference, the operational temperature will be a little warmer than Triton but a little cooler than the satellites or Uranus. The effect of perpetual shade will be about like having it out at 25 AU. |
|
|
Dec 30 2021, 06:04 PM
Post
#131
|
|
Senior Member Group: Members Posts: 1629 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Perhaps a low light camera can see the silhouette and/or use starlight (if it doesn't emit too much heat energy, or somehow get in the way of the deployment)?
As for refueling, IIRC the fuel tank may be accessible just in case. The sunshield covers have now been released and rolled up! https://blogs.nasa.gov/webb/2021/12/30/webb...nshield-covers/ -------------------- Steve [ my home page and planetary maps page ]
|
|
|
Dec 31 2021, 06:46 PM
Post
#132
|
|
Member Group: Members Posts: 404 Joined: 5-January 10 Member No.: 5161 |
Maybe they left out cameras to eliminate any unnecessary heat generating activities, especially on the cold mirror side.
|
|
|
Jan 1 2022, 01:46 AM
Post
#133
|
|
Senior Member Group: Members Posts: 1629 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Some suspense with a successful first side arm deployment of the sun shield:
https://blogs.nasa.gov/webb/2021/12/31/firs...-booms-deploys/ -------------------- Steve [ my home page and planetary maps page ]
|
|
|
Jan 1 2022, 11:16 PM
Post
#134
|
|
Member Group: Members Posts: 191 Joined: 20-November 06 From: Saint Louis Member No.: 1376 |
It looks like they're giving themselves some time after successfully extending both booms.
Tensioning will start tomorrow. Webb Sunshield Tensioning To Begin Tomorrow Edit - Here it is, the next day. The JWST team has decided to take another day and proceed tomorrow. Deployment Timeline Adjusted as Team Focuses on Observatory Operations -------------------- - Matt
|
|
|
Jan 3 2022, 07:13 PM
Post
#135
|
|
Member Group: Members Posts: 444 Joined: 1-July 05 From: New York City Member No.: 424 |
Maybe they left out cameras to eliminate any unnecessary heat generating activities, especially on the cold mirror side. The spacecraft was originally scheduled to launch in 2007. I suspect that its design was set in stone before the the recent proliferation of high resolution engineering cameras in planetary missions became practical. I doubt that a proposal to add such cameras during the final years of testing and trouble-shooting would have been viewed with much enthusiasm, even if the cameras could have seen anything and wouldn’t be a risk to the operating temperature. |
|
|
Lo-Fi Version | Time is now: 28th April 2024 - 04:22 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |