Where have you been since last December? We've been following its progress at (IIRC)
Yesterday, my husband said, "It's great to see so many technologies I worked on actually in use."
PBS Nova recently aired a good 1-hour spot on the James Webb project. Also some youtube stuff out there. One huge difference from the Hubble is that the James Webb is much further out there - so it cannot be visited by any manned mission for repairs. John T.
Yeah.
My husband knows one of the guys who worked on the Hubble's optical problem back in the day. Something involving math, I think.
" Hubble is the only telescope designed to be maintained in space by astronauts. Five Space Shuttle missions have repaired, upgraded, and replaced systems on the telescope, including all five of the main instruments. " as per wiki John T.
There was a rumor that the engineers screwed up a conversion from metric to imperial. This rumor has been disproven.
As far as I understand it, the mirror was ground too flat due to a calibration error with some laser equipment.
"Perkin-Elmer had ground Hubble’s primary mirror to the wrong specification. The company had removed too much glass, resulting in a primary mirror that was too flat by about 1/50 the width of a human hair."
I like to see a metric to imperial conversion error that would result in a difference that small.
Which is a problem since this is what the first image looks like:
They were too cheep to build a very expensive machine to check out the mirror before it was launched. Had they done that maybe it would have worked correctly.
Where'd you get that from?
They actually tested it via 2 different methods. One that was certified for final testing and a much less sophisticated method that some refer to as a "sanity check". "Are we close? If this test is within X percentage points of specs, we can keep going."
Turns out the less sophisticated method indicated an issue but the scientists decide to ignore the warnings and use the results from the "very expensive machine" instead.
They later found out that the lens in the "very expensive machine" was out of alignment by about 1 mm so the test results were not accurate. Had they paused and dug deeper to figure out why the results of the 2 tests were so different, they would have found the issue with the "very expensive machine."
Seems to me I remember James Web had a bunch of trouble getting running properly. And just recently they have got it the way they want. So that is probably where Dean is coming from. Result are finally coming out.
What problems are you referring to? Just curious.
There were long delays in getting the telescope up into space - i.e. issues on the ground, design and build issues. Like a decade plus delay in launch and close to triple the high end ($3.5B) of the original cost estimate.
AFAIK, things have been pretty smooth since it was launched. Back in January they had some minor issues with over heating heat shield deployment motors and a minor lack of power, but they were resolved quickly and easily.
They've always said that it would take ~6 months after launch before the first images were released and they just about nailed that. The scientists themselves have been looking at images for months as they align and calibrate the instruments and mirrors.
There's a link to their weekly blog below. They talk about the more than 3 month cooling down period for the telescope to shed the last of its heat since it launched. They couldn't even properly align and calibrate the instruments until it was completely cooled down. I especially like the fact that some of mirror adjustments are measured in nanometers. "At full speed, it takes about a day to move all the segments by just 1 millimeter. It’s about the same speed at which grass grows!"
I read that one section of the mirror has already been dinged by a micro-meteor. The are fully exposed to space, so that was expected.
That all makes sense. There is no "convection" in the hard vacuum of space, so what would cool in minutes on earth would take a very long time in space. It is like being surrounded by miles and miles of insulation. (I love how Hollywood embellishes on this and thing freeze almost instantly when exposed to hard space.) In space, heat has to be exchanged by radiation.
That issue and many others will be massively improved when you commie leftist subhuman turds are finally rounded up and eradicated.
You keep threatening that. We're still waiting for the big show.
Do you have a time frame for the event? Is the "round-up" site prepped and ready for guests?
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