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Russian space lens ZIKAR-1A
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PostPosted: Mon Sep 03, 2018 10:47 am    Post subject: Russian space lens ZIKAR-1A Reply with quote

Now this is a really, really rare lens:

ZIKAR-1A, from the russian space defence program, to detect fired rockets aiming at the (then) USSR from about 45.000 km away, mounted at some camera system from a satellite in orbit around earth. It is a catadioptric system with two Beryllium mirrors, f1.2/100mm and some fluorite aux. lenses. Several such systems were successfully launched into space and were in operation several years long.



Last edited by kds315* on Fri Sep 14, 2018 7:00 am; edited 2 times in total


PostPosted: Mon Sep 03, 2018 10:53 am    Post subject: Reply with quote

how large / heavy is it?


PostPosted: Mon Sep 03, 2018 11:00 am    Post subject: Reply with quote

kansalliskalaCafe wrote:
how large / heavy is it?


About 120mm long and 100mm diameter; space objects always have to be compact and light
because of the huge effort to get them there (at least in the 70s when this was done)


PostPosted: Mon Sep 03, 2018 11:02 am    Post subject: Reply with quote

Supercool Like 1


PostPosted: Mon Sep 03, 2018 12:04 pm    Post subject: Re: Russian space lens ZIKAR-1A Reply with quote

Like 1 Like 1 Just curious, where did you find it??


PostPosted: Mon Sep 03, 2018 12:12 pm    Post subject: Re: Russian space lens ZIKAR-1A Reply with quote

wolan wrote:
Like 1 Like 1 Just curious, where did you find it??


A guy contacted me and offered it, so the lens found me... Wink


PostPosted: Mon Sep 03, 2018 12:43 pm    Post subject: Reply with quote

kds315* wrote:
kansalliskalaCafe wrote:
how large / heavy is it?


About 120mm long and 100mm diameter; space objects always have to be compact and light
because of the huge effort to get them there (at least in the 70s when this was done)


looks huge

so the numbers on the name plate are really tiny


PostPosted: Mon Sep 03, 2018 5:27 pm    Post subject: Reply with quote

Yea, this might be a lens from some auxiliary opto unit, not the main one. The early warning satellites use *huge* telescopes (70's Око ~300kg) which are operated in IR - to detect starting inter-continental missile's exhaust heat.

Anyway, looking forward to the pictures


PostPosted: Mon Sep 03, 2018 5:33 pm    Post subject: Reply with quote

Do you know why they used beryllium instead of aluminum ?


PostPosted: Mon Sep 03, 2018 5:52 pm    Post subject: Reply with quote

Wow, amazing Klaus, another piece of space exploration history. So, the main question, how does it perform for UV imaging Smile ?


PostPosted: Tue Sep 04, 2018 6:59 am    Post subject: Reply with quote

y wrote:
Yea, this might be a lens from some auxiliary opto unit, not the main one. The early warning satellites use *huge* telescopes (70's Око ~300kg) which are operated in IR - to detect starting inter-continental missile's exhaust heat.

Anyway, looking forward to the pictures


Well, I have have the lens document that came with it and it clearly states its name ZIKAR-1A, also here in this russian site this lens is mentioned: http://www.kik-sssr.ru/Main_Oko.htm Wink

((google translated))
On September 19, 1972, the first space-520 experimental SPACECRAFT was launched from the Plesetsk cosmodrome. On Board in addition to the control equipment and reset information were installed two types of BAO: television (MBT-A) and heat direction finding (105-A). The TV-type equipment was a two-chamber receiver with IR-vidicons Radian with a lens”Zikar-1A". One camera had a relatively wide angle of view (SPK) and the other narrow band (UPK). The field of vision of the CPC was inside the field of vision of the SPC. The TP-type equipment had one line of fifty sensitive elements scanning the field with the help of a swinging mirror. The total field of view was no more than 10 square degrees.((end))


jamaeolus wrote:
Do you know why they used beryllium instead of aluminum ?

Beryllium is often now used for such mirrors (like the James WEBB telescope), read here: https://materion.com/resource-center/news-and-announcements/beryllium-and-composites/beryllium-mirrors-for-space-telescopes---beryllium-optics-enable-space-technologies


JMC wrote:
Wow, amazing Klaus, another piece of space exploration history. So, the main question, how does it perform for UV imaging Smile ?

Actually it is designed for SWIR, 1.5 - 2.5 micron, not for UV - but you may have see those very interesting contributions about SWIR at UVP that triggered my interest. Those SWIR cameras are getting affordable now Wink


PostPosted: Tue Sep 04, 2018 7:40 am    Post subject: Reply with quote

kds315* wrote:
JMC wrote:
Wow, amazing Klaus, another piece of space exploration history. So, the main question, how does it perform for UV imaging Smile ?

Actually it is designed for SWIR, 1.5 - 2.5 micron, not for UV - but you may have see those very interesting contributions about SWIR at UVP that triggered my interest. Those SWIR cameras are getting affordable now Wink


Interesting, thanks for explaining Klaus.


PostPosted: Tue Sep 04, 2018 4:09 pm    Post subject: Reply with quote

At first I was confused by your James Webb reference as I knew that mirror is gold. So I went to the NASA site for clarification. The mirror "chassis" as it were is beryllium which is then plated with gold, instead of aluminum, as they are after IR wavelengths. The beryllium component is not the actual mirror, but the blank, which on earth would be glass. The coating is likely aluminum. Any better answers are certainly welcome to contradict me as I am certainly no expert in space based astronomy.


PostPosted: Tue Sep 04, 2018 4:24 pm    Post subject: Reply with quote

jamaeolus wrote:
At first I was confused by your James Webb reference as I knew that mirror is gold. So I went to the NASA site for clarification. The mirror "chassis" as it were is beryllium which is then plated with gold, instead of aluminum, as they are after IR wavelengths. The beryllium component is not the actual mirror, but the blank, which on earth would be glass. The coating is likely aluminum. Any better answers are certainly welcome to contradict me as I am certainly no expert in space based astronomy.


Well, had you read the link I provided with that embedded pdf in it, I would not have to contradict: the three James Webb telescope mirrors are made of Beryllium with an overcoating of gold to enhance the IR reflectivity. But the mirror IS Beryllium, precicison grinded and polished. The gold is just there to enhance, a coating. Twisted Evil


PostPosted: Tue Sep 04, 2018 9:29 pm    Post subject: Reply with quote

Klaus, I did read the first part, but then went to the NASA site. My understanding of coatings must be flawed. I defer to your expertise. Upon more research I came to the conclusion that the gold IS the mirror. (Not beryllium) Consider that gold at 100nm is virtually opaque according to this: answer at Stack exchange
https://chemistry.stackexchange.com/questions/15258/why-cant-light-pass-through-a-gold-foil-but-alpha-particles-can

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Light can pass through a gold foil though, it just has to be thin enough.

Pure gold is a very malleable substance and can be beaten with a hammer into foils of around 100 nm thickness. Sources suggest the gold foil used in the Geiger–Marsden experiment (known more commonly as the Rutherford gold foil experiment) was about 86 nm thick. Somewhere around this region of thickness, gold starts letting light through, as well as alpha particles. It is well known that ~20 nm thick gold (or any other metal) deposited onto a surface by thermal evaporation in a vacuum is essentially invisible and can be used as a transparent conducting surface/electrode. As the foil gets thicker, the gold starts to absorb a noticeable amount of photons, especially in the violet/blue part of the electromagnetic spectrum, while scattering away the red light. The light scattered off a semi-transparent gold film acquires a reddish/yellow tinge, while the light that still does make it through is blueish. When the film reaches 100 nm or so, it becomes practically as opaque as the bulk metal.

In truth, comparing the mean free path or collision cross-sections of photons and alpha particles through a gold sheet is somewhat more complicated than just saying alpha particles should penetrate less because they're massive, so it would be conceivable for a film of appropriate thickness to block photons yet still allow alpha particles through. A very coarse, hand-waving explanation is that photons are absorbed in the electrosphere of a gold atom, while an alpha particle is only significantly pushed away if it bangs almost straight into the nucleus, a region composing approximately 10−15 of the volume of the atom.

And the NASA site has the gold vapor deposition at: 100nm.

Anyways, just my take on it and I am just a humble pill slinger....


PostPosted: Wed Sep 05, 2018 5:39 pm    Post subject: Reply with quote

kds315* wrote:
Well, I have have the lens document that came with it and it clearly states its name ZIKAR-1A, also here in this russian site this lens is mentioned: http://www.kik-sssr.ru/Main_Oko.htm
Yea, your lens was a part of TB (телевизионная аппаратура) unit. The main TП (теплопеленгатор) unit is described at the bottom - it's the massive lens (mirror diameter of up to 100cm) I had described.

Early versions УС-К diameter of 50cm. Later version УС-КМО 100cm.


1 - a mirror made of vitrified beryllium with a diameter of 60 cm,
the surface form is a convex hyperbola of the second order.
2 - a mirror made of vitrified beryllium with a diameter of 100 cm, a surface shape of an aspheric of the 12th order.
3 - lenses made of fluorides of calcium and lithium.


PostPosted: Wed Sep 05, 2018 9:17 pm    Post subject: Reply with quote

jamaeolus wrote:
Klaus, I did read the first part, but then went to the NASA site. My understanding of coatings must be flawed. I defer to your expertise. Upon more research I came to the conclusion that the gold IS the mirror. (Not beryllium) Consider that gold at 100nm is virtually opaque according to this: answer at Stack exchange
https://chemistry.stackexchange.com/questions/15258/why-cant-light-pass-through-a-gold-foil-but-alpha-particles-can

1 Answer
active oldest votes
up vote
9
down vote
Light can pass through a gold foil though, it just has to be thin enough.

Pure gold is a very malleable substance and can be beaten with a hammer into foils of around 100 nm thickness. Sources suggest the gold foil used in the Geiger–Marsden experiment (known more commonly as the Rutherford gold foil experiment) was about 86 nm thick. Somewhere around this region of thickness, gold starts letting light through, as well as alpha particles. It is well known that ~20 nm thick gold (or any other metal) deposited onto a surface by thermal evaporation in a vacuum is essentially invisible and can be used as a transparent conducting surface/electrode. As the foil gets thicker, the gold starts to absorb a noticeable amount of photons, especially in the violet/blue part of the electromagnetic spectrum, while scattering away the red light. The light scattered off a semi-transparent gold film acquires a reddish/yellow tinge, while the light that still does make it through is blueish. When the film reaches 100 nm or so, it becomes practically as opaque as the bulk metal.

In truth, comparing the mean free path or collision cross-sections of photons and alpha particles through a gold sheet is somewhat more complicated than just saying alpha particles should penetrate less because they're massive, so it would be conceivable for a film of appropriate thickness to block photons yet still allow alpha particles through. A very coarse, hand-waving explanation is that photons are absorbed in the electrosphere of a gold atom, while an alpha particle is only significantly pushed away if it bangs almost straight into the nucleus, a region composing approximately 10−15 of the volume of the atom.

And the NASA site has the gold vapor deposition at: 100nm.

Anyways, just my take on it and I am just a humble pill slinger....


Ehemm, the gold does not define the mirror, it is the precision grinded beryllium mirror. Indeed the IR reflection happens from the gold surface coating. SO the shape and precision comes from the beryllium mirror, the reflection from gold. Would you then call it "gold mirror", nope, a Beryllium mirror it is. Cheez...


PostPosted: Wed Sep 05, 2018 9:19 pm    Post subject: Reply with quote

y wrote:
kds315* wrote:
Well, I have have the lens document that came with it and it clearly states its name ZIKAR-1A, also here in this russian site this lens is mentioned: http://www.kik-sssr.ru/Main_Oko.htm
Yea, your lens was a part of TB (телевизионная аппаратура) unit. The main TП (теплопеленгатор) unit is described at the bottom - it's the massive lens (mirror diameter of up to 100cm) I had described.

Early versions УС-К diameter of 50cm. Later version УС-КМО 100cm.


1 - a mirror made of vitrified beryllium with a diameter of 60 cm,
the surface form is a convex hyperbola of the second order.
2 - a mirror made of vitrified beryllium with a diameter of 100 cm, a surface shape of an aspheric of the 12th order.
3 - lenses made of fluorides of calcium and lithium.


Thank you, as I have already stated in the quoted and translated russian text, it is / was for the Television unit (телевизионная аппаратура) which also worked in infrared.


PostPosted: Wed Sep 05, 2018 9:51 pm    Post subject: Reply with quote

kds315* wrote:
jamaeolus wrote:
At first I was confused by your James Webb reference as I knew that mirror is gold. So I went to the NASA site for clarification. The mirror "chassis" as it were is beryllium which is then plated with gold, instead of aluminum, as they are after IR wavelengths. The beryllium component is not the actual mirror, but the blank, which on earth would be glass. The coating is likely aluminum. Any better answers are certainly welcome to contradict me as I am certainly no expert in space based astronomy.


Well, had you read the link I provided with that embedded pdf in it, I would not have to contradict: the three James Webb telescope mirrors are made of Beryllium with an overcoating of gold to enhance the IR reflectivity. But the mirror IS Beryllium, precicison grinded and polished. The gold is just there to enhance, a coating. Twisted Evil

Gold works better than most other metals for IR.
Beryllium has a good very-low temperature properties.
https://www.nasa.gov/topics/technology/features/webb-beryllium.html

Gold: https://jwst.nasa.gov/mirrors.html#5


PostPosted: Sat Sep 15, 2018 4:02 pm    Post subject: Reply with quote

Measured the lens' transmission and the big surprise it, that it has a flat transmission and also works down to 320nm in UV!