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Re:NASA's James Webb Space Telescope Launch Delayed to December by LeifCarrotson on Wednesday September 08, 2021 @05:55PM (#28463531)
The good news is that the trajectory of timeline slip is less than one week per week, and if that holds true, the two will eventually rendezvous.

In 1996, it was estimated for 2007, fast forwarding a bit to 2018, it slipped one year from an estimated launch in 2020 to 2021, in 2020 it slipped from March 2021 to July, by January 2021 it slipped to October 31st, and it's been known since June, 14 weeks ago, that it wasn't likely to meet that date.

At this rate, I estimate the current date will intercept the target date in early 2022.

Re:NASA's James Webb Space Telescope Launch Delayed to December by perihelions on Wednesday September 08, 2021 @06:09PM (#28463667)
>"trajectory of timeline slip is less than one week per week, and if that holds true, the two will eventually rendezvous."

Not mathematically certain. If the timeline slip is a sequence like [1-1/2^k]_{k=1...} = {1/2 week, 3/4 weeks, 7/8 weeks, 15/16 weeks...}, then it's possible the project timeline could diverge forever. (This is just a restatement of Zeno's paradox).

Re:NASA's James Webb Space Telescope Launch Delayed to December by TeMPOraL on Wednesday September 08, 2021 @06:26PM (#28463817)
The act of delaying launch takes non-zero amount of time in the real world, so at some point the slippage fraction gets so small that the launch will happen while being about to be rescheduled.
Re:NASA's James Webb Space Telescope Launch Delayed to December by perihelions on Wednesday September 08, 2021 @06:29PM (#28463840)
You just keep observing the quantum superposition of launch/no-launch, using increasingly powerful lasers.
Re:NASA's James Webb Space Telescope Launch Delayed to December by halfmatthalfcat on Wednesday September 08, 2021 @10:38PM (#28465598)
This whole line on conversation made my night, haven’t laughed this hard in a while.
Re:NASA's James Webb Space Telescope Launch Delayed to December by jhgb on Wednesday September 08, 2021 @07:29PM (#28464322)
> This is just a restatement of Zeno's paradox

I thought Zeno's paradox was caused by lack of understanding of infinitesimal calculus by Ancient Greeks? That is, in situations where a series converges despite an having infinite number of elements. Divergent series like yours shouldn't constitute such a paradox, since they both have an infinite number of elements AND diverge.

Re:NASA's James Webb Space Telescope Launch Delayed to December by nine_k on Wednesday September 08, 2021 @10:36PM (#28465582)
There is an old joke.

A crate of beer is standing in the end of a magical room; each step towards the crate is half as short as the preceding one.

A mathematician and an engineer enter the room. The engineer starts walking towards the chest, while the mathematician stands still.

M: Why are you doing this? You can't reach it in finite time anyway!

E: But in a few hundred steps I'll be close enough for all practical purposes!

Re:NASA's James Webb Space Telescope Launch Delayed to December by rland on Wednesday September 08, 2021 @10:49PM (#28465658)
Another one:

An infinite number of mathematicians walk into a bar. The first one orders a pint. The second one orders half a pint. When the third orders a quarter of a pint, the bartender rolls his eyes, places two beers on the bar, and says "you all need to learn your limits!"

Re:NASA's James Webb Space Telescope Launch Delayed to December by SAI_Peregrinus on Wednesday September 08, 2021 @11:13PM (#28465795)
An infinite number of mathematicians walk into a bar. The first orders a beer. The second orders half a beer. The third orders a quarter of a beer. Before the next one can order, the bartender says, "You're all assholes," and pours two beers.

They got lucky to have a bartender who knows his customer's limits.

-----------------

An infinite number of mathematicians walk into a bar

The first mathematician orders a beer

The second orders half a beer

"I don't serve half-beers" the bartender replies

"Excuse me?" Asks mathematician #2

"What kind of bar serves half-beers?" The bartender remarks. "That's ridiculous."

"Oh c'mon" says mathematician #1 "do you know how hard it is to collect an infinite number of us? Just play along"

"There are very strict laws on how I can serve drinks. I couldn't serve you half a beer even if I wanted to."

"But that's not a problem" mathematician #3 chimes in "at the end of the joke you serve us a whole number of beers. You see, when you take the sum of a continuously halving function-"

"I know how limits work" interjects the bartender "Oh, alright then. I didn't want to assume a bartender would be familiar with such advanced mathematics"

"Are you kidding me?" The bartender replies, "you learn limits in like, 9th grade! What kind of mathematician thinks limits are advanced mathematics?"

"HE'S ON TO US" mathematician #1 screeches

Simultaneously, every mathematician opens their mouth and out pours a cloud of multicolored mosquitoes. Each mathematician is bellowing insects of a different shade. The mosquitoes form into a singular, polychromatic swarm. "FOOLS" it booms in unison, "I WILL INFECT EVERY BEING ON THIS PATHETIC PLANET WITH MALARIA"

The bartender stands fearless against the technicolor hoard. "But wait" he interrupts, thinking fast, "if you do that, politicians will use the catastrophe as an excuse to implement free healthcare. Think of how much that will hurt the taxpayers!"

The mosquitoes fall silent for a brief moment. "My God, you're right. We didn't think about the economy! Very well, we will not attack this dimension. FOR THE TAXPAYERS!" and with that, they vanish.

A nearby barfly stumbles over to the bartender. "How did you know that that would work?"

"It's simple really" the bartender says. "I saw that the vectors formed a gradient, and therefore must be conservative."

Re:NASA's James Webb Space Telescope Launch Delayed to December by slownews45 on Wednesday September 08, 2021 @06:25PM (#28463806)
Damn - these are full time employment deals for folks. 25 years on one project!

Question - they have a ton of shielding for solar radiation - can they not locate this thing in a shadow area somewhere?

Re:NASA's James Webb Space Telescope Launch Delayed to December by perihelions on Wednesday September 08, 2021 @06:46PM (#28464004)
There aren't any permanent shadows in space. Every orbit goes "around" eventually -- and there's no configuration where some combination of objects works to permanently shadow you.

(A technical exception is a planetary solar L2 Lagrange point [0], *if* it would occur close enough to a planet to be totally eclipsed. But that doesn't happen (AFAIK) -- they're generally far enough away that although the planet is always in front of the sun, the planet's disk is much smaller than the solar disk. Like a partial eclipse).

With cryogenic cooling, you have an even more difficult challenge: the light of a planet's infrared radiation emission is something you also have to shield. That's a major reason JWST (and similar cryogenic telescopes) go to solar L2: its sunshield doesn't only block out the sun -- it simultaneously blocks out the sun and the Earth. That's the unique advantage of the solar L2 point: the sun and Earth are always in the same direction.

[0] https://en.wikipedia.org/wiki/Lagrange_point

Re:NASA's James Webb Space Telescope Launch Delayed to December by bagels on Wednesday September 08, 2021 @07:37PM (#28464375)
Inside of certain polar craters can satisfy the shade question. Pretty limited utility for a telescope, doubly for solar powered ones.
Re:NASA's James Webb Space Telescope Launch Delayed to December by perihelions on Wednesday September 08, 2021 @06:40PM (#28463946)
Related:

https://news.ycombinator.com/item?id=10462349 ("NASA's last original Voyager engineer retires at 80")

Re:NASA's James Webb Space Telescope Launch Delayed to December by zardo on Wednesday September 08, 2021 @06:32PM (#28463862)
Possibly, but they couldn't power it by attaching solar panels.
Re:NASA's James Webb Space Telescope Launch Delayed to December by causality0 on Wednesday September 08, 2021 @06:32PM (#28463863)
Being in a shadow area would mean it would be in orbit of something, and at best it would be in shadow 50% of the time and still need the same amount of shielding for daylight operations. Being in orbit would also mean its position would be much less stable than it will be at the L2 point.
Re:NASA's James Webb Space Telescope Launch Delayed to December by marcodiego on Wednesday September 08, 2021 @07:28PM (#28464317)
Why not a landed observatory on the moon? During the day it could recharge batteries; during the night it could perform observations.
Re:NASA's James Webb Space Telescope Launch Delayed to December by bagels on Thursday September 09, 2021 @03:45AM (#28467309)
Getting to l2 is a lot easier than landing a sensitive device on the moon. Also don't have to worry as much about energy emissions from the moon.
Re:NASA's James Webb Space Telescope Launch Delayed to December by dzhiurgis on Wednesday September 08, 2021 @06:44PM (#28463987)
Had my reddit reminder trigger back in July. I think I've set it up like 6 years ago. Amazed it actually worked.
Re:NASA's James Webb Space Telescope Launch Delayed to December by tshaddox on Wednesday September 08, 2021 @05:59PM (#28463574)
> The good news is that the trajectory of timeline slip is less than one week per week, and if that holds true, the two will eventually rendezvous.

Not if the timeline slips such that at each slip the delta between the current time and the launch time decreases by 50%.

Re:NASA's James Webb Space Telescope Launch Delayed to December by feoren on Wednesday September 08, 2021 @06:58PM (#28464104)
It still works in that case, actually; you just have to pass through a singularity where the timeline is delayed infinitely many times, but the total amount of each of those infinite delays is finite. 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + ... = 1.

This is the answer to Zeno's paradox. A sports reporter gives an update every time Hercules catches up to where the tortoise was the last time he gave an update. All that happens is the sports reporter eventually needs to talk faster and faster and faster, and eventually try to give infinite updates right as Hercules passes the tortoise. Then the reporter's vocal chords explode, but otherwise the race proceeds as you would expect. (That is, just because a description of an event is infinitely long, does not mean the event itself is infinitely long in any sense.)

Re:NASA's James Webb Space Telescope Launch Delayed to December by tshaddox on Wednesday September 08, 2021 @07:39PM (#28464391)
Lol yeah, that was a goof. I had Zeno’s paradox in mind and intended to choose a divergent series but accidentally used the textbook convergent one. Let’s swap it out for the harmonic series.
Re:NASA's James Webb Space Telescope Launch Delayed to December by irrelative on Wednesday September 08, 2021 @06:00PM (#28463589)
Re:NASA's James Webb Space Telescope Launch Delayed to December by nsxwolf on Wednesday September 08, 2021 @06:03PM (#28463622)
I cannot foresee a timeline where it does not explode on the pad.
Re:NASA's James Webb Space Telescope Launch Delayed to December by mmazing on Wednesday September 08, 2021 @06:20PM (#28463763)
I hope you are incorrect. I will be extremely sad if this mission is not successful.
Re:NASA's James Webb Space Telescope Launch Delayed to December by chroem- on Wednesday September 08, 2021 @06:32PM (#28463858)
Although tragic, it would be a fitting end to this boondoggle of a project. JWST was originally marketed as a quick, cheap win for NASA, but it turned into the polar opposite of that.
Re:NASA's James Webb Space Telescope Launch Delayed to December by asmithmd1 on Wednesday September 08, 2021 @06:50PM (#28464044)
My thinking is the solar shield gets stuck/torn on deployment. Among the numerous bad decisions, they have no cameras watching the deployment
Re:NASA's James Webb Space Telescope Launch Delayed to December by krisoft on Wednesday September 08, 2021 @07:43PM (#28464421)
Why is that a bad decision? Would watching it help in any way?
Re:NASA's James Webb Space Telescope Launch Delayed to December by asmithmd1 on Wednesday September 08, 2021 @08:24PM (#28464711)
There are about 50 deployment actions that have to occur. If everything works perfectly, great. But if something hangs up or gets tangled, the people running the mission are blind when trying to debug the problem
Re:NASA's James Webb Space Telescope Launch Delayed to December by dylan604 on Wednesday September 08, 2021 @08:09PM (#28464606)
I mean, SpaceX would have put 4 cameras on it. Also, pics, or it didn't happen.
Re:NASA's James Webb Space Telescope Launch Delayed to December by ufmace on Wednesday September 08, 2021 @11:45PM (#28465966)
But they all would have broken due to "communication issues"
Re:NASA's James Webb Space Telescope Launch Delayed to December by Mountain_Skies on Wednesday September 08, 2021 @08:33PM (#28464779)
To learn from what went wrong. Even if it cannot be corrected for the telescope, we can hopefully see enough about what went wrong to be able to prevent the same thing from happening on future complex satellites.
Re:NASA's James Webb Space Telescope Launch Delayed to December by khuey on Wednesday September 08, 2021 @06:42PM (#28463971)
Most of the time and money was spent on design. If it blows up they should be able to build a second one for a fraction of the time/cost of the first one.
Re:NASA's James Webb Space Telescope Launch Delayed to December by oh_sigh on Wednesday September 08, 2021 @07:15PM (#28464235)
Wasn't a major part of the problem that the design kept changing based on the pushed timeline? So what we are getting now is completely different from what was planned in 1996 to be launched in 2007? If that's the case, and the JWST fails to deploy, we probably wouldn't just build another copy of it - we would build a completely new/reworked space telescope that would take another 25 years to design/launch.
Re:NASA's James Webb Space Telescope Launch Delayed to December by janmo on Wednesday September 08, 2021 @07:08PM (#28464180)
In this case, they should have build a half dozen instead of one..
Re:NASA's James Webb Space Telescope Launch Delayed to December by oh_sigh on Wednesday September 08, 2021 @07:16PM (#28464240)
"First rule in government spending: Why build one, when you can build two for twice the price?"

-Contact

Re:NASA's James Webb Space Telescope Launch Delayed to December by chasd00 on Wednesday September 08, 2021 @09:12PM (#28465068)
I was expecting it to read something like “why build two when you can build one for the price of 5”
Re:NASA's James Webb Space Telescope Launch Delayed to December by haswell on Wednesday September 08, 2021 @08:40PM (#28464831)
On what do you base this conclusion?
Re:NASA's James Webb Space Telescope Launch Delayed to December by nsxwolf on Wednesday September 08, 2021 @08:54PM (#28464957)
A keen sense of irony.
Re:NASA's James Webb Space Telescope Launch Delayed to December by dnautics on Wednesday September 08, 2021 @11:38PM (#28465925)
I see I'm not the only one that believes the universe operates to maximize irony (also, I correctly predicted both Boeing dreamliner snafus)
Re:NASA's James Webb Space Telescope Launch Delayed to December by Covzire on Wednesday September 08, 2021 @06:14PM (#28463705)
Why does the launch date keep slipping? I've been looking forward to this launch for a very long time and I'm getting pretty irked at the teams sending this up, to the point where even if they are completely successful I hope they don't get put on another big project like this again. Hopefully the delays have been because it's a lot harder to send this to L2 successfully than anyone thought or could have known, and now we do.
Re:NASA's James Webb Space Telescope Launch Delayed to December by colechristensen on Wednesday September 08, 2021 @07:54PM (#28464497)
Why? Time estimation is hard and you’re a pretty bad PM of a scientific missions primary goal is to launch by a date. You keep working until you are confident you can do it right.

Failures happen when delivery dates are more important than quality.

Re:NASA's James Webb Space Telescope Launch Delayed to December by sp332 on Wednesday September 08, 2021 @06:45PM (#28463994)
Re:NASA's James Webb Space Telescope Launch Delayed to December by newnamenewface on Wednesday September 08, 2021 @08:39PM (#28464821)
This is complete hearsay but I was sat next to a engineer working on the project on a recent flight. He mentioned to me that 1.) it would be delayed past October till December, and probably early into next year, and 2.) COVID, like any good excuse, was being used because it was there and not necessarily because it caused the delays.

Maybe the engineer was just telling a story with a bit of flair but I believed him.

Re:NASA's James Webb Space Telescope Launch Delayed to December by thehappypm on Wednesday September 08, 2021 @09:11PM (#28465064)
Anything can be blamed on covid or global warming.