Posted on 03/04/2018 8:12:32 PM PST by Voption
The concept of what would become the Hubble Space Telescope was first envisioned after World War II, when astronomer Lyman Spitzer and a handful of scientists began a fifty year struggle to build the first space telescope capable of seeing beyond Earth's atmospheric veil. Robert Zimmerman, author of "The Universe in a Mirror: The Saga of the Hubble Space Telescope and the Visionaries Who Built It," takes us behind the scenes, explaining how some of Hubble's advocates sacrificed careers and family, and how others devoted their lives to the telescope only to have their hopes and reputations shattered when its mirror was found to be flawed. More than any other scientific instrument invented since Galileo first looked through a spyglass in 1609, the Hubble Space Telescope has helped to reshape our view of the universe. Yet the effort to build this space telescope was long, hard, painful, and often destructive to the individuals involved.
(Excerpt) Read more at youtu.be ...
I’ve always wondered How could They have
screwed up the Mirror?
That looks fascinating; thanks for posting.
“I didn’t fail. I just found 2,000 ways not to make a lightbulb; I only needed to find one way to make it work.”
-Thomas Edison
I still believe that the hubble is a 1980’s spy satellite pointed outwards.
At the time, it was ascribed to a conversion error between metric and inches. I think I read later it was something else, which eludes me.
Fortunately, the “prescription” for the mirror, was ground “perfectly wrong,” so they were able to take corrective action.
Interesting article about the possibility of re-boosting:
http://spacenews.com/op-ed-a-not-so-final-servicing-mission/
Thanks for posting. A refreshing change. I just put a hold on the book at our library. I’m #1 in line for it!
Good deal!
In the meantime you can download & read a free PDF of the 1st Chapter. I put a link to the books home-page in another Post.
Zimmerman discusses that whole thing.
In brief;
The device they used to test the mirror during grinding, was mechanically mounted with a small gap that wasn’t taken into account in the calculations. Fortunately,(or not) it was a consistent-error during grinding, so the whole mirror was ground to the exact wrong prescription.
I’m about a third of the way through the video — this is fantastic! Love it! I never knew about the genesis of the Large Space Telescope. Robert Zimmerman is masterful at delivering such a lecture!
Personal aside: Zimmerman mentions the early space programs and how weather satellites were among the first applications because resolution could be low (because hurricanes were so huge), the earth and clouds were bright (short exposures), and it was easy to transmit the data.
My Dad was the General Electric Program Manager in charge of the Nimbus project in the early 60s. I was about 12 or 13 at the time and remember him telling me all about space imaging and the importance of “false color.” I still remember asking him what was wrong with “real color” and why were they using “false” color. Nimbus 1 was launched August 28, 1964 into near-polar, sun-synchronous orbit.
Dad went on to manage the “Earth Resources Technology Satellite 1” (or ERTS”) at General Electric’s (GE’s) Space Division in Valley Forge, Pennsylvania (later renamed “Landsat 1”). It was a modified version of the Nimbus 4 meteorological satellite and was launched on July 23, 1972 by a Delta 900 rocket from Vandenberg Air Force Base in California.
I never did anything in my career remotely as much fun or as exciting as what Dad worked on.
Not the main mirror -- the mounting of the secondary mirror. IIRC, it was a screwup between metric and English units of measure...
Obviously, it was fixable -- and fixed by shuttle astronauts.
,,,or, better, today's is a Hubble -- pointed Earthward..
We’ll see if he tells the real story.....metrics are difficult on large scale optics particularly if you are using outdated methods
It was a failure in the metrics method chosen......old school optical engineer didn’t want to use new tools
Ping for later
referencing Metric vs. English units; You might be thinking of a space probe that was lost, due to just that exact problem. The Name of that probe escapes me, but in a critical part of the software, the Units weren’t consistent between metric/English. (I recall it crashed, but not sure if it was on the Moon or Mars.)
The Hubble situation involved the physical placement of a mechanical device they use to monitor if the grinding was proceeding equally across the surface. The test device wasn’t actually at the physical location they thought it was from which they calculated the various optical formulas. Somebody used a shim during installation of that device and that gap measurement wasn’t known to the people who used the device.
Amplified by the failure to test the lens at subsequent stages. Dum, dum, dum.
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