JWST Launch NASA Livestream • Hacker News Board

Re: JWST Launch NASA Livestream

#11

Post by nabla9 » Sat, Dec 25, 2021, 11:52 AM UTC

guerrilla wrote: post #8

nabla9 wrote: post #7

Super exiting. * JWST costs ~$10B, about the same as Large Hadron Collider or aircraft carrier. * JWST has 344 single-point-of-failures (SPOF), 80% of them related to deployment. * No ability for repair. JWST goes to orbit the Sun 1.5 million kilometers away from the Earth, almost 4 times the distance between Earth and Moon. * Ariane 5 launch failure rate is 0.045 --- assuming 0.045 launch failure probability, and 0.…

> 0.0001 failure probability for each SPOF Why did you choose this value for the assumption? Is that standard or a publicized detail?

I picked relatively high number 1/10000 as a starting point to get a ballpark. NASA has never tested deployment in the zero gravity. It's unlikely that the probability is higher.

Ariane launch failure probability dominates if you add zeros.

  0.00001  -> 4.8% 
  0.000001 -> 4.5%

Re: JWST Launch NASA Livestream

#12

Post by Jellyspice » Sat, Dec 25, 2021, 11:53 AM UTC

perihelions wrote: post #10

32 minute launch window starting at 12:20 UTC (07:20 EST). When this comment's indicated age is ~30 minutes. https://blogs.nasa.gov/webb/2021/12/21/james-webb-space-tele...

Countdown page https://jwst.nasa.gov/content/webbLaunch/countdown.html

Re: JWST Launch NASA Livestream

#13

Post by chinathrow » Sat, Dec 25, 2021, 12:08 PM UTC

instagraham wrote: post #9

I wonder what the Eye of God will look like through this telescope. It's much farther out than Hubble.

I had to look this one up - https://en.wikipedia.org/wiki/Helix_Nebula

Re: JWST Launch NASA Livestream

#14

Post by ryzvonusef » Sat, Dec 25, 2021, 12:24 PM UTC

launch looks good!

Re: JWST Launch NASA Livestream

#15

Post by dredmorbius » Sat, Dec 25, 2021, 12:44 PM UTC

Good launch.

And over 472k viewers on the livestream. Good service by YouTube.

(I don't get to praise them often, credit where due.)

All launch events seemed precisely on schedule and trajectory.

The 2nd stage even caught the solar panel deploy on camera, which I believe was an unexpected bonus.

Now we've got 30 days of deployment events, another 300 or so SPOFs to clear. Arrival at L2 in a month.

Six months to chill and calibrate (with or without Netflix I'm not sure).

Science starts in June.

Re: JWST Launch NASA Livestream

#16

Post by ryzvonusef » Sat, Dec 25, 2021, 12:56 PM UTC

ryzvonusef wrote: post #14

launch looks good!

https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html

Re: JWST Launch NASA Livestream

#17

Post by Symbiote » Sat, Dec 25, 2021, 12:57 PM UTC

Additional comments on the ESA livestream (posted a few minutes before this one): https://news.ycombinator.com/item?id=29681636

Re: JWST Launch NASA Livestream

#18

Post by ravisutrave » Sat, Dec 25, 2021, 1:01 PM UTC

"Webb will soon begin an approximately two-week process to deploy its antennas, mirrors, and sunshield."

https://twitter.com/NASA/status/1474724928360525827

Re: JWST Launch NASA Livestream

#19

Post by wiz21c » Sat, Dec 25, 2021, 1:38 PM UTC

nabla9 wrote: post #7

Super exiting. * JWST costs ~$10B, about the same as Large Hadron Collider or aircraft carrier. * JWST has 344 single-point-of-failures (SPOF), 80% of them related to deployment. * No ability for repair. JWST goes to orbit the Sun 1.5 million kilometers away from the Earth, almost 4 times the distance between Earth and Moon. * Ariane 5 launch failure rate is 0.045 --- assuming 0.045 launch failure probability, and 0.…

This makes a 92% success rate... I'm not sure I would cross a road if I had that much chance to be hit by a car :-)

Re: JWST Launch NASA Livestream

#20

Post by jacquesm » Sat, Dec 25, 2021, 1:52 PM UTC

dredmorbius wrote: post #15

Good launch. And over 472k viewers on the livestream. Good service by YouTube. (I don't get to praise them often, credit where due.) All launch events seemed precisely on schedule and trajectory. The 2nd stage even caught the solar panel deploy on camera, which I believe was an unexpected bonus. Now we've got 30 days of deployment events, another 300 or so SPOFs to clear. Arrival at L2 in a month. Six months to chill…

> 472k viewers on the livestream

We had about 11K on STS 82, which I still think was the high point of my career. Back in the day with capacity being what it was that put a serious strain on the internet as a whole, shortly after that we had to move to the other side of the Atlantic be able to continue to operate.