I do have a question about JWST that I wasn't able to find a fine answer in other forums.<p>A lot of people and engineers are saying that the JWST is a marvel of engineering, with truly inovative technical solutions and a giant step up compared to Hubble Telescope. And it does seems like so!<p>However, I'm always baffled how everyone seems proud that the telescope has something like 200 SPOF during deployment, and if even one of them fails the whole mission could fail.<p>I know that each step has probably been throughoutly tested, and that the acceptable probability of failure of each one of those steps has been deemed acceptable. But I'm still surprised that people are proudly conflating excellent engineering with a design that has a large number of spofs.<p>In my domain this would be considered as a terrible design (aka "hope is not a strategy"), even given the constraints of mass and volume that such project incur: 200 hundred low probability events, chained, can get in the realm of possible.<p>I can't imagine JSWT team doing "bad engineering", so I'm sure I'm missing a piece. Is it only PR that underline this aspect? Is JWST as brittle as the news want to make us think? Or are there technical reasons or acceptable failure modes that gives confidence that those steps are not as critical as the news let us people know?
We're told that since JWT will travel very far away before it unfolds and activates all its systems, there is no practical way to service it if something would go wrong.<p>Why can't it unfold etc in Earth orbit, where a repair mission can be sent if needed, and <i>then</i> travel to its Lagrange point?
Countdown with links to livestream and blog here: <a href="https://www.jwst.nasa.gov/content/webbLaunch/countdown.html" rel="nofollow">https://www.jwst.nasa.gov/content/webbLaunch/countdown.html</a>
If you want to skip the Super Bowl pre-game, the actual launch window starts at 7:20 am EST (12:20 UTC) and lasts for 31 minutes.<p>It can launch anytime during that window.
Decades of meticulous planning and they couldn't give their teams a day off on Christmas? Of course it could be that consensus was this beats any other kind of activity that day in which case fair enough. :-)
Interesting they found a way to add a hidden risk variable to the launch, by sending it up on a day people are having to choose to not be with their families. Have a bad feeling about this :/