My god! It’s full of stars!
First light in this instance is kinda…weird.
*old man in the back of the theater shaking his cane*
Focus!!
There’s a short youtube video here - although it was disappointing that they didn’t put little cameras to show us any live pics of the telescope, there is a lens on one of the main cameras that takes a selfie of the mirror array.
Dr. Becky geeked out about it. It’s not quite as intense as her launch video but her enthusiasm is infectious.
The JWST blog uses kelvins in the plural. Examples:
Yeah I saw that too. Love her videos
I was wrong about this; the real solution is even more elegant and clever. There’s a video here:
Instead of a clutch, there are two disks that can each have a pin along their circumference and can only transmit force when the pins are in contact. Essentially, it’s designed to have almost a full revolution of backlash.
When you want a coarse adjustment, you just keep going until the pins come in contact and engage the ball screw drive. Then, for the fine adjustment, you back up, and then only the cam that drives the compound flexure is active (until you hit the pin from the other direction).
Thus, they can conditionally drive either coarse+fine or fine-only with a single stepper motor and no other control inputs. Requires some software work to track the various positions, but software has no mass, and doesn’t break once you write it.
In my career, writing some software and using much more other software, I seems to me I’ve seen plenty of counter-examples to both these assertions.
It can certainly seem otherwise at times… we do joke about “bit rot”.
But seriously, bit rot only happens when the environment or assumptions change. There are a few small parts of our codebase that I wrote 20 years ago and are identical today. They’re pieces that make minimal assumptions about their inputs and have no dependencies at all. It’s rare that you can get away with that. On other hand, there are some automation scripts I wrote which were immensely reliable for a few years… until recently, when they all fell apart. The data they were processing grew in size, slowly but inexorably, until they exceeded some indirect thresholds I’d put in the script. Then the whole thing collapsed.
In any case, I expect the driver for these actuators to really be a write-once thing. They have deterministic action and can limit the range of acceptable input. Though things could get interesting if they have to deal with a mechanical failure of some kind. Sometimes software can save the day on these sorts of issues.
I see they’ve added some more deployment details on the “where’s Webb” site …
Currently on Segment Image Identification !!
A new picture available from Webb on the blog : Webb Team Brings 18 Dots of Starlight Into Hexagonal Formation – James Webb Space Telescope
Maybe “Jus’ Chillin’” could be their current motto.
Why would someone do this - misinformation or plain ignorance ?
Clicks. it’s not ignorance, they aren’t trying to push some alternate reality. But they know people are searching for JWST and will click on this.
I saw that same video this weekend and posed that very question. I notice on our YouTube feed there are lots of suggestions for videos like “The unsettling alien discovery JWST just revealed”. When you click on it, there’s no mention of any images or aliens. Just the usual discussions about mirror alignment and cold temperatures.
Then they are bastards.
Amen. There is a reason they have comments disabled.
Images from mirrors now stacked into a single image. Still lots of adjustments to do.
https://blogs.nasa.gov/webb/2022/02/25/webb-mirror-alignment-continues-successfully/
Brian
From the “Where Is Webb” site today:
That’s impressive that they will be able to line them all up with greater resolution than one wave length. I guess it helps that they are looking at infra-red and not ultraviolet.