Macdoc wrote:...loved seeing the live feed of the solar array unfold.

That was an animation.

Nah - the animation finishes at about 1:37 when the 2nd stage on-board camera takes over. The solar array deploys just before the 3 minute mark in this "final view" clip:


Link for when it does not play here: https://www.youtube.com/watch?v=jC2Ra1_61iw

I guess it will take about 2 weeks to get to L2 but it will probably unfold and unfurl right away.

Caper wrote::thumbup:

(But, of course, Americans have to poison it with religious nonsense.)

What happened?

newolder wrote:Nah - the animation finishes at about 1:37 when the 2nd stage on-board camera takes over. The solar array deploys just before the 3 minute mark in this "final view" clip:


Link for when it does not play here: https://www.youtube.com/watch?v=jC2Ra1_61iw

Ah, yes. Thanks for the correction.

It's the heat shield unfolding at L2 that is the next big test and it will be a while before we know.
Something bittersweet about that last live glimpse ...2 decades+ of work for 10's of thousands and then off into the dark.

Reminds me of the head guy for the Lunar Lander in From Earth to the Moon...that was an amazing episode.
I would think everyone in this thread has seen that series.



Good info here on what is coming ... two weeks of terror...
https://www.bbc.com/news/science-environment-59138682

Good graphics on the deployment...Webb is hustling along..


https://www.jwst.nasa.gov/content/webbL ... sWebb.html

The naming controversy aside, I can understand why it's named after a bureaucrat instead of a scientist, as is usually the case with such instruments ... because it's basically a rococo piece of engineering bureaucracy writ large.

Apparently, no less than 344 separate moving parts have to move into the right places, and in the right order, simply in order to have an instrument that can be left to cool down to its operating temperature. Failure of any one of those movements will result in this being the most expensive piece of junk in space.

Then, after everything has fallen into place, and the instrument's cold side is at its operating temperature, it then has to be calibrated. Because it is required, in effect, to assemble itself into place in space, pre-calibration isn't an option. This will take at least 3 months to complete.

Which means that the instrument will not be performing any actual scientific experiments until June 2022.

Plus, if anything malfunctions, it's beyond the reach of a repair crew. So whoever built it, has had to build it to operate maintenance-free for 6 years minimum.

We're now going to have all the fun of waiting two weeks to find out if everything IS working maintenance-free.

Calilasseia wrote:Apparently, no less than 344 separate moving parts have to move into the right places, and in the right order, simply in order to have an instrument that can be left to cool down to its operating temperature. Failure of any one of those movements will result in this being the most expensive piece of junk in space.

I wonder what probability of success was deemed acceptable?

90%? 99%?

Solving x^344 = 0.99, say, suggests that each of those 344 components has to have a reliability of at least 0.999971.

Calilasseia wrote:Plus, if anything malfunctions, it's beyond the reach of a repair crew. So whoever built it, has had to build it to operate maintenance-free for 6 years minimum.

Does it have enough fuel to do a de-orbit burn and bring it back to LEO where they could potentially do some maintenance?

I suspect not. It only has enough fuel for a one way trip to L2, and for mid-mission corrections. A return to LEO isn't part of the mission planning. The big problem with a return to LEO being, of course, that the cold side of the instrument will warm up again, and all the fun and games of cooling and recalibration will have to be endured once the instrument returns to L2 a second time.

Indeed, despite the cost overruns of the original instrument, now that we know how to build one, it would probably be easier to have 3 or 4 replacement instruments on standby (with all the advantages of reducing unit cost), and simply send up a replacement instrument when the original finally stops working. Whether anyone will have the sense to follow this thinking, however, remains to be seen. Though if this course of action is taken, ensuring that the replacement instrument doesn't come into contact with the dead one will concentrate minds wonderfully as well.

The_Piper wrote:I guess it will take about 2 weeks to get to L2 but it will probably unfold and unfurl right away.

Caper wrote::thumbup:

(But, of course, Americans have to poison it with religious nonsense.)

What happened?

I certainly don't mean all Americans, but ...

From 2:00.

You made it sound like there was more than one.

In regard to Cali's comments above, there apparently is a feed system on board that would allow for the refuelling of the telescope to take it beyond the10 year projected mission period. The refuelling vehicle has yet to be designed though!

(This was mentioned on the live NASA feed I was listening to, so no link)

That would imply there are contingency plans for a trip to L2 if necessary/feasible.

Political wonk ....no science background...claim to fame flew as a passenger on the shuttle.

“The NASA administrator should be a consummate space professional who is technically and scientifically competent, and is a skilled executive,” he said during Bridenstine’s confirmation hearing. “This committee has heard me say many times: NASA is not political. The leader of NASA should not be political. The leader of NASA should not be bipartisan; the leader of NASA should be nonpartisan.

guess who said that .....why Bill Nelson ...
and he's too fucking old....

more

https://www.washingtonpost.com/technolo ... ll-nelson/

^^^ Yes, that reasoning for objecting to Jim Bridenstine's appointment as NASA's administrator makes Bill Nelson look somewhat hypocritical now.

Nobody should be surprised that he saw fit to include religious mumbo jumbo in his missive. Now 79 years old, Bill Nelson attended Baptist and Episcopal churches but later was baptized through immersion in a Baptist church. In 2005 he joined the First Presbyterian Church in Orlando. Though a long serving Democrat Senator for Florida, he voted with President Donald Trump's positions 42.5% of the time. In the 115th Congress, Nelson was rated more conservative than 93% of other congressional Democrats.

Fucking boomers won't let go and they might just start another war. The dumpf will be 78 in 2024 and Biden ....if he makes it 82

FFS

Joe Biden reportedly telling allies he will run for president again in 2024

https://www.theguardian.com/us-news/202 ... -president

he's likely to have to take a mandatory drivers test but okay to run the US....

Calilasseia wrote:The big problem with a return to LEO being...

...The conversion of gravitational potential energy into kinetic energy.

Calilasseia wrote:Though if this course of action is taken, ensuring that the replacement instrument doesn't come into contact with the dead one will concentrate minds wonderfully as well.

The dead one won't remain at L2. Any orbit at L2 is metastable.

Matt_B wrote:I'm fully expecting the next NASA space telescope to be named after Pat Robertson at this rate.

When I've been on campus at various US universities, I have always been struck by the penchant for naming absolutely everything imaginable after some person (a benefactor no doubt). The Charles P. Wagner lecture hall, The Miriam Rosenfeld sports arena, The Ronnie Yang library, The Nora L. Hirsch memorial staircase, The Ricardo Gonzalez handrail, The Jerome Broadstaffe door handle, The Lillian M. Sert bathroom stall.

It was true to a lesser extent in the UK, but usually the names were of long dead and mostly forgotten local benefactors, and nothing smaller than a building. In Japan, most universities go with a fairly quotidian system of Alphabetical or Alphanumerical or some kind of local/seasonal system. My office is in J building on my campus and I teach mostly in C or S buildings.

I've never really understood the thinking behind naming things after people. I would loathe having anything at all named 'in my honour'.

(Sorry for the derail....the new telescope is a wonder and I'm looking forward to seeing the data when it is up and running. Nice overview by Cali of the long and intricate processes that are needed to bring the instrument up to functionality. A good reminder that science takes time and is not calibrated to human gratification temporal scales.)

don't get me started wrote:I've never really understood the thinking behind naming things after people. I would loathe having anything at all named 'in my honour'.

In Australia it is sometimes used as a means to mock someone.

At the north end of my erstwhile stomping grounds, Tamarama Beach

2nd planned course correction burn happened in the UK night. Next up is sunshield deployment that has many stages and will take up to a week, all being well. Breathe in, breathe out ...