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#1 TG

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Posted 30 January 2013 - 04:45 PM

I was watching this video, a series of slo-mo shuttle launch films taken by NASA and at the 38:20 mark, while showing a view from a few miles away, the commentator mentions the kind of "lens" used. After a bit of sleuthing, it turns out that it's a Brashear SR-150 and its design is...drumroll... our beloved Schmidt Cassegrain with corrective lenses, 15.4 in aperture, 4000mm f.l., close to a C14.

http://www2.l-3com.c..._Range_Lens.pdf

Any folks here know more about these scopes? I was under the impression that NASA uses C11/C14s as well but no sign of those here.

BTW, the video is longish but very interesting especially with the commentary (e.g., what are those sparkly things that are always being emitted before ignition? The commentators tell you).


Tanveer.

#2 rmollise

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Posted 30 January 2013 - 06:11 PM

NASA has often used Celestrons and Questars aboard spacecraft, but not as tracking cameras, which I believe this is what you are referring to here.

#3 Motokid600

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Posted 30 January 2013 - 07:42 PM

Idk but I want one lol. Looks like they may be built for terrestrial observing. Or.. built JUST to observe rocket launches maybe. I imagine the highly magnified image you got when watching a shuttle launch is probably from these scopes. Killer mount too lol

#4 shawnhar

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Posted 30 January 2013 - 09:45 PM

Best space shuttle vid EVER! Thanks for the link!
And is it just me or do those guys sound like the McKenzie brothers?
"Take off A"...kept hearing it in my head but they never said it.

#5 laconicsax

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Posted 31 January 2013 - 03:45 AM

It's probably a custom made "mirror lens." Mirror lenses are basically SCTs that mount to a camera. They usually have a focal length of 300 or 500mm, so a 4000mm one would almost certainly have to be custom made.

#6 bcuddihee

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Posted 31 January 2013 - 08:45 AM

looks as though they have corrector lenses built into the rear of the optical train ..similar to the celestron hd series.

#7 Eddgie

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Posted 31 January 2013 - 01:36 PM

The sparks are igniters that will burn off any hydrogen gas that is vented so there is not an explosion when the main engines light off.

As I understand it, they do not iginite the engines. The only purpose is to keep the hydrogen that vents just before main engine ignition from forming an explosive cloud.

Rocket scientest.. They have to think of everything... LOL.

#8 rg55

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Posted 31 January 2013 - 05:16 PM

In a previous life I was involved in such things:

http://www.ebay.com/...issile-Track...

You could probably get some nice shots of the space station, eh?
:cool:

#9 snowcrow

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Posted 31 January 2013 - 06:05 PM

Yah right, try lugging that out to the dark site!! :bigshock:

#10 TG

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Posted 31 January 2013 - 06:29 PM

The sparks are igniters that will burn off any hydrogen gas that is vented so there is not an explosion when the main engines light off.

As I understand it, they do not iginite the engines. The only purpose is to keep the hydrogen that vents just before main engine ignition from forming an explosive cloud.

Rocket scientest.. They have to think of everything... LOL.


Hey Eddgie, don't spoil it for other people. :)

#11 TG

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Posted 31 January 2013 - 06:39 PM

NASA has often used Celestrons and Questars aboard spacecraft, but not as tracking cameras, which I believe this is what you are referring to here.


I distinctly remember reading that they used C11s or C14s (I forget which) for long range tracking of launches but it looks like that wasn't true, at least for the Shuttle.

Tanveer.

#12 iluxo

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Posted 31 January 2013 - 11:46 PM

L3 is a defence contractor.

15" is small for L3, their catalog starts at 1 metre.

#13 EFT

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Posted 01 February 2013 - 10:58 AM

That was a cool video.

Why use something that costs $6000 off the shelf when you can use something custom that costs 100 times that amount? Actually, I suspect that these are very rugged instruments, but it is the government after all.

#14 Geo.

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Posted 06 February 2013 - 10:38 AM

The "corrector" optics are probably how they get a large enough image to expose all of the 70mm film. Talk about LER. Looks like about a foot of eye relief here!






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