I found a russian document about it HERE (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)
From that and more data I found that it was designed for SWIR, 1.5 - 2.5 microns, I assumed that this lens would only useful for IR and possible visible light, but having it on my spectrometric UV-VIS-IR system surprisingly revealed that it could be used in UV down to 320nm!
|(own spectrometric measurement)|
Further research showed that his lens was a part of TB (телевизионная аппаратура) unit, possibly used as an auxiliary lens to help aiming a much larger main lens unit. That main TП (теплопеленгатор) unit was a massive lens with a main mirror having a diameter of one meter (100 centimeters or 1.000 millimeters) [early versions УС-К had a diameter of 50cm; later versions УС-КМО had 100cm (1.000 millimeters)].
That impressive main unit УС-К/УС-КМО looked like this:
1 - a mirror made of vitrified beryllium with a diameter of 60 cm, the surface shape being a convex hyperbola of the second order.
2 - a mirror made of vitrified beryllium with a diameter of 100 cm, a surface shape being an aspheric of the 12th order.
3 - correcting lenses made of fluorides of calcium and lithium.
That ZIKAR-1A lens will be given a suitable adaption to fit my digital multispectral cameras and I will certainly take multispectral photos with it as soon as possible and report about here later on. That will not be easy, as it has a very short back focal length.
Data of this lens, as well as its normal (= non catadioptric) quartz fluorite sister lenses with shorter focal length may be found on my macrolenses database site HERE
Stay tuned, more will follow on that fascinating subject...