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One of the big numbers that been thrown around is that JWST has 344 single points of failure in its mission. Now that deployment has been completed, is there somewhere that lists how many of those points we have passed?
Since 90% of the cost is probably in R+D of the telescope, one could build and deploy another for another 10%. Why isn't this done? Why is every space telescope completely unique?
Also if you were to build just 2 or 3 of them, you can't expect any economy of scale.
On top of that, the operational cost of JWST is expected to be around 1B$ for it's lifetime, you could expect that to be similar for every single replica you have.
And finally, you can only put one per rocket, and just the rocket is about 200M$ dollar, and you need to add all the cost of shipping the telescope to Guyana, that's not cheap.
So overall, while a second replica would not cost you another 10B, it would probably cost in the order of 3-5B$, that's a lot of billions for a telescope with exactly identical capabilities to another one. It would still be useful, as astronomers are going to have to compete for time on the JWST and not everyone will be served, but the benefits of a second one would be marginal compared to the benefits of the first one. So the price/benefit ratio might actually be worse on a new copy.
Meanwhile, there is a myriad of other very cool NASA projects that would greatly benefit from 3-5B$ instead and do things that we haven't done so far.
Shame.
Earlier quoted context omitted.
But the chain itself can be considered as one component and it becomes a single point of failure. Or if we go in the opposite direction, then we can breakdown links and say "Every single grain boundary is a single point of failure".
Partially-agreed on the former, but not the latter. So long as the chain is not loaded near its tensile limit, then the grain boundaries that support the load within each link do so in parallel and are therefore redundant. The selection of the allegory of the chain was intentional -- each link must be properly formed, or the entire chain will fail. If it breaks, it is surely correct to say, "the chain broke", but in…
Also, I don't want to underplay JWST's success or its challenges. But, when saying 300+ SPOF conditions, one has to specify at what abstraction level. Otherwise, it can be misleading.
For those not up on the project, what are some of the earliest novel types of information we expect to receive from it?
It will take another 6 months before JWST will go into operation it seems. This page has a list of approved programs. https://www.stsci.edu/jwst/science-execution/approved-progra...
One of the big numbers that been thrown around is that JWST has 344 single points of failure in its mission. Now that deployment has been completed, is there somewhere that lists how many of those points we have passed?
Can anyone elaborate on these single points of failures? For example, are they actually single points of failure? Or is it a bit of exaggeration for marketing purposes (a bit of under promise, over deliver)?
Some other parts don't and cannot have redundancy due to design.
Since 90% of the cost is probably in R+D of the telescope, one could build and deploy another for another 10%. Why isn't this done? Why is every space telescope completely unique?
For the JWST, is there even room for a 2nd telescope at L2?
One of the big numbers that been thrown around is that JWST has 344 single points of failure in its mission. Now that deployment has been completed, is there somewhere that lists how many of those points we have passed?
Can anyone elaborate on these single points of failures? For example, are they actually single points of failure? Or is it a bit of exaggeration for marketing purposes (a bit of under promise, over deliver)?
No mention of ESA again, looks like it is solely NASA project, which it is not. Shame.
Earlier quoted context omitted.
Similar question was just asked during press conference and the answer was "telescope is cooling a bit faster than we simulated but it is not a significant difference, it might be ready one or two days ahead of current estimation". Current timeline is for getting all 4 cameras to work, but I think only one needs cryogenic cooling, other 3 could work with just sunshield. In another answer one of the engineers said tha…
Surely, it can take pics during this time with suboptimal cooling. Probably hard to resist the temptation:) There might be good engineering reasons to experiment early, like testing comms systems etc
Here is first technical image from Hubble, before its mirror's flaw was discovered: https://stsci-opo.org/STScI-01EVTBEME0059ASGX8X3DFWZMX.jpg
