Day 2 Operations with the James Webb Space Telescope is about to begin | Hacker News Reader

Day 2 Operations with the James Webb Space Telescope is about to begin

flyingbarron.medium.com

125 pointsflyingbarron49 comments

In case you haven't seen the first image yet, here's a gif comparison of the first JWST photo with a Hubble photo of the same region of the sky: https://i.redd.it/9uyhwijeo0b91.gif

EDIT: Better comparison: https://imgsli.com/MTE2Mjc3

If this "day 2" does not refer to an actual day (which does not have a real meaning if you're not on a planet), but to a phase, why do they call it "day" and not "phase"? Does "phase" have some kind of negative connotation, does it sound too "scientific"?

I honestly don't know.

Just to clarify, the term "Day-2" isn't from NASA, it's a universal engineering term - which mostly happens on Earth ;)

I'm guessing it's just a planning term - like D-Day :shrugs:

I see Day-0, Day-1, Day-2 etc. used in the context of business planning quite frequently.

So its in 3 days?

* https://dzone.com/articles/defining-day-2-operations

* https://about.gitlab.com/solutions/day-2-ops/

Still doesn't explain why "Day" and not "Phase" or "Stage" or "Level" or "Period"

I think I covered the basic explanation in my article as well as dzone and gitlab did in theirs.

I think "day one" was an existing phrase that was confusingly extended to cover other "start of phase" concepts.

Sounds like a nice way to trick your management though, "Uh no, it won't have feature X on day one, but that will be working by Day-2."

I'll admit I've never heard of day 0/1/2 before.

I think the terms day 0/1/2 have caught on because they are constant across projects regardless how lacking or overboard the phase planning was. I.e. the project may or may not have much more detailed actual phases and those phases may or may not be obvious to someone without a background in the project but anyone can understand where the project is at without first ingesting the entire project plan.

Funny you would mention days being a constant for a space telescope on an orbit around the sun, where days definitely do not mean the same thing as they do on earth :)

hmm maybe day 2 is after day 1 and before day 3 but not necessarily adjacent, meaning a specific day kicks something off any number of days after a previous planned day? So over the course of the next month we have 3 special days that kick off different phases.

See for example "day 1" (Bezos / Amazon):

https://www.forbes.com/sites/quora/2017/04/21/what-is-jeff-b...

(Not an edorsement / fandom.)

Okay, anyone think it's strange that they pushed back the release at the last minute (to 1730EDT) -- and they have done a pretty poor job of making that obvious on their channels (eg twitter or live NASAtv feed). Strange strange.

Not particularly, would assume something came up and the briefing needed to be pushed 30 min. Don't think it's particularly strange for the President's schedule to be moved around.

As for the tweets, there is a tweet from yesterday: https://twitter.com/NASA/status/1546290906046816256

What exactly were you looking for?

I was hoping for updates via the channels they released? Not everyone is keeping up on Twitter. It would make sense to make note of the delay on the previously linked NASAtv feed. And an update with a few mins of lead time for when they were going to go Live? Instead, they just cut into it at a random time some 90 mins later.

And the tweet you linked to is part of the problem as it features the incorrect time.

45 minutes as of now, it’s getting ridiculous..

Yeah, get a move on!

Time to see how much damage that micrometeoroid did.

I'm pretty sure that if there was any bad news they'd be managing expectations.

This is the quiet of confidence, I think :)

Here's to hoping :D

As long as it didn’t hit any of the actuator mechanism my guess is it probably will just add a bit of noise/bias that they can largely eliminate.

https://practicalastrophotography.com/a-brief-guide-to-calib...

Statistically speaking, it's quite concerning that such a large hit has occurred so soon after launch and thus does not bode well for the predicted lifespan of the telescope.

We pray it was an extreme outlier.

It's like when you get a new phone and scratch the screen just taking the screen cover off.

I have several telescopes and I have dropped things in the mirrors quite often. The decrease in quality from a damaged mirror is almost zero. You only lose a tiny part of the total surface. Is not like hubble that had the wrong shape. A tiny speck in the mirror is likely undetectable. Even a bigger one wont affect that much.

A man fired multiple bullets into a telescope and put many holes in the primary mirror, but the science capabilities were only minimally affected: https://en.wikipedia.org/wiki/Harlan_J._Smith_Telescope

This telescope design already has a giant hole in the middle, and the light-collecting capabilities are hardly affected by small holes.

I think it's kind of like how FaceID or TouchID work regardless of orientation of face/fingerprint. Or how locating a radio source from data across multiple detectors would utilize math and any damage would drop out as slightly more noise. Modern cameras often have dead pixels in their detectors but they're just skipped in the output photos.

I have no technical insight, but I'm SO stoked to see these images tomorrow.

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