The James Webb Space Telescope has only gone and deployed its primary mirror
- Reference: 1641816009
- News link: https://www.theregister.co.uk/2022/01/10/james_webb_space_telescope/
- Source link:
The deployment of the sunshield required to keep things cool was successfully completed last week as the spacecraft hurtled toward its final destination, an orbit around the second Lagrange point (1.5 million km, or nearly 1 million miles from Earth.) Following the deployment of the secondary mirror, the final step was the unfolding of the JWST's primary mirror.
The segmented primary mirror is 6.5 metres across and consists of 18 gold-coated mirror segments. Folded in order to fit in the fairing of the Ariane 5 rocket that launched it, the first panel was deployed on 7 January and the second locked into place on 8 January. The completed mirror is the largest ever launched into space.
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It is quite the engineering feat. Although it was exhaustively tested prior to launch, any issues the team might have faced during the deployment in space could have resulted in an abrupt curtailment of the mission. Unlike the Hubble Space Telescope during the Shuttle days, there is currently no way for astronauts to reach the JWST. However, things have gone well.
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As NASA administrator Bill Nelson put it: "Each feat already achieved and future accomplishment is a testament to the thousands of innovators who poured their life's passion into this mission."
There is still months of work to do before the European Space Agency (ESA), NASA and Canadian Space Agency collaboration can begin observations. Another burn is coming up and those 18 primary mirror segments must be moved to align the optics. The science instruments also need to be calibrated.
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As the agencies ticked off each JWST milestone, the deployments were represented during briefings by computer generated graphics, prompting the question of: "Why no cameras to watch the deployment of the multi-billion dollar observatory?"
[6]Robotic arm on China's space station does a demo, swings out 20 degrees and back while holding cargo ship
[7]NASA confirms International Space Station is to keep orbiting through 2030
[8]A moment of tension as the James Webb Space Telescope stretches sunshield on way to L2 destination
[9]Boffins' first take on asteroid dust from Japanese probe: Carbon rich, less lumpy than expected
Ostensibly a reasonable question, and one that had come up and been rejected during the design of the observatory. Aside from the issue of lighting (the sun-facing side would suffer from extreme glare and contrast issues) and temperature (a camera on the cold side would have to work at cryogenic temperatures) there was the question of benefit of the extra complexity. Certainly when compared to the telemetry that would flow from the various mechanical, thermal and electrical sensors built into the spacecraft.
The movement of the individual mirror segments out their launch configuration is expected to be completed approximately 27 days following launch. A day and a half later, the JWST will complete its insertion into a HALO orbit around L2. It will take a good few weeks for the instruments to cool in the shade of the sunshield and the remaining five months will be all about calibration. ®
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[1] https://www.nasa.gov/press-release/nasa-s-webb-telescope-reaches-major-milestone-as-mirror-unfolds
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YdxmPgPgYQSk@P4COMDR3AAAAIU&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
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[6] https://www.theregister.com/2022/01/07/chinas_space_station_robotic_arm/
[7] https://www.theregister.com/2022/01/05/iss_2030/
[8] https://www.theregister.com/2022/01/04/jwst_sunshield/
[9] https://www.theregister.com/2021/12/22/first_ryugu_asteroid_sample_analyses_published/
[10] https://whitepapers.theregister.com/
Obligatory
[1]Where's Webb?
We have a telescope... now to make sure it can focus and detect photons.
[1] https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html
Re: Obligatory
Technically, it's a Webbbrowser isn't it?
Re: Obligatory
Point Hubble at it to check one side of it......!
Re: Obligatory
> Where's Webb?
The timeline's quite pretty but when I dragged the little yellow triangle to the right a bit but it didn't seem to speed up the deployment - is the site broken?
Re: Obligatory
It's quite along way away so there is some latency - have you checked back ?
Congratulations to the team on such a resounding success so far!
As to the reporter who asked why there are no cameras, I suggest they go out with their crew to film the event to capture an 'exclusive'... :P
I thought I'd seen video on the https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html site that were from cameras. Then I saw your post and thought -329F. Good simulations though
There is a difference between the science side of NASA and the 'astronaut had a gorilla suit on the ISS for the lulz' side of NASA.
Although I suspect if it was being designed today there would be more thought put into having a "PR" camera.
If you care to read the article, you'll find out why they didn't waste money on such frivolity...
Excessive - but a Space Camera Drone?
Could a separate camera "drone" be deployed to watch these things - limited lifetime, but useful for both engineers and public spectacle? When done with could be used to knock one of Musk's satellites out "Intergalactic Billiards" style?
Re: Excessive - but a Space Camera Drone?
"Could a separate camera "drone" be deployed to watch these things"
Well, it could...but it would need to provide it's own lighting, as the main part of the WEBB is in shadow (and hence darkness) and is facing away from the Sun.
The WEBB is also beyond the orbit of the Moon too, so any reflected light from there would not help.
The other issue of course is "adding complexity" as this drone would need a comms link to the WEBB and then any video signal would need to be piggy-backed onto the various other telemetry signals being sent back to MOC...and given that WEBB is travelling at abt 1000 mph, large packets of data are more prone to "interference".
And then there is the question of controlling the drone so that the "video director" can bring the WEBB into focus and be watching the "required" section of the Telescope.
And the drone camera would be operating at around -300 deg F...
Of course given the $10BN cost of the WEBB, adding such "extras" probably wouldn't add much cost - but given it would be used for maybe a few minutes each day (to hopefully observe such deployments), I doubt it was high up on the "original" specifications list.
Re: Excessive - but a Space Camera Drone?
And the drone camera would be operating at around -300 deg F...
-185℃ would have been better or perhaps 88K
Re: Excessive - but a Space Camera Drone?
Minus twenty and a bit Hilton.
Re: Excessive - but a Space Camera Drone?
Voyager managed to take detailed pictures of Jupiter, Saturn etc back in 1970s and 80s, pretty sure tech has moved on a bit? Plus we see live images from outside all sorts of rockets, capsules etc.
Be just down to $$$$ for a decent solution?
Re: Excessive - but a Space Camera Drone?
They're called spy satellites - unfortunately they're all pointing towards Earth, and can't repurpose one because then someone would have to admit they exist and are able to do it all
Re: Excessive - but a Space Camera Drone?
No, because the sunshield would be extremely vulnerable to thruster exhaust from any such drone, and the exhaust might deposit on the mirror.
Also, can you guarantee your drone won't malfunction and crash into your $10 billion observatory?
Re: Excessive - but a Space Camera Drone?
They probably also reckoned that Webb was complicated enough as it was without the extra of worrying about deploying and running a web cam too.
Re: Excessive - but a Space Camera Drone?
A Webbcam, Shirley?
The Lack of Cameras
"Why no cameras to watch the deployment of the multi-billion dollar observatory?"
Simple: When was this device designed? It started in 1996. What was the state of space rated video cameras then? They were all built for space probes - there were no space rated cameras to get you the video you wanted at the time.
And there was no way anyone was going to delay the schedule (Spend money) again just to beam glamor shots.
Re: The Lack of Cameras
Add to this the added complexity, thus the increased risk for the telescope, the weight, the unexpected side effects in the long run... Having a camera just to watch the unfolding wasn't worth the effort.
Let's us Europeans self-congratulate. [1]Ariane 5 made such an outstanding job that enough fuel can be kept to extend JWST life
[1] https://www.esa.int/Science_Exploration/Space_Science/Webb/Precise_Ariane_5_launch_likely_to_extend_Webb_s_expected_lifetime
Re: The Lack of Cameras
Also the goPro pictures from SpaceX boosters are a lot closer to Earth.
Getting video back from a 1st stage booster dropping from a few km is a lot easier than getting video back from something heading past the moon.
And the pictures would look less 'real' than the simulations of stuff unfolding anyway - there is nowhere you can put a camera for anything except the mirror unfolding and that would mostly be in shadow.
NASA being NASA :)
NASA excels in building kit that works and lasts. That's one of the reasons we won't see pictures for over a month.
During that time, NASA will individually test each one of the over 100 actuators that move the mirror segments. Then they will begin the process of aligning the primary and secondary mirrors using the actuators.
Slow and steady wins the race. Go boffins.
Fantastic stuff, and quite telling that the actual Rocket Science bit (ie. The upcoming burn) is just a footnote in the complexity worries about JWST.
Rocket Science isn't what it used to be... How far we've come :-)
It's all going too well!
Long may it continue!