Editing Luna 3 (section)

== Lunar photography ==
[[File:Luna-3 phototelegraph system at Tsiolkovsky State Museum of the History of Cosmonautics.jpg|thumb|Luna 3 phototelegraph system at [[Tsiolkovsky State Museum of the History of Cosmonautics]]]]

[[File:Luna 3 moon.jpg|right|thumb|The first view returned by Luna 3 showed the far side of the Moon was very different from the near side, most noticeably in its lack of [[lunar maria]] (the dark areas)]]

[[File:Luna 3 grainy photo restoration and comparison with LRO.png|thumb|When the first image of the far side of the Moon (A) is restored using advanced noise-removal techniques (B) and compared to the later LRO mission from NASA (C) the important feature points are distinctly visible and a clear, one-to-one mapping of the visible feature points are noticeable.]]

The purpose of this experiment was to obtain photographs of the lunar surface as the spacecraft flew by the Moon. The imaging system was designated Yenisey-2 and consisted of a dual-lens camera AFA-E1, an automatic film processing unit, and a scanner.{{sfn|Siddiqi|2018|p=14}} The lenses on the camera were a 200&nbsp;mm focal length, [[F-number|''f'']]/5.6 [[aperture]] objective and a 500&nbsp;mm, ''f''/9.5 [[photographic lens|objective]]. The camera carried 40 frames of American-made temperature- and radiation-resistant 35mm isochrome [[photographic film|film]] recovered by the Soviets from downed American [[Project Genetrix|Genetrix]] espionage balloons.<ref>{{Cite web |last=Oseman |first=Neil |title=Luna 3: The 1959 photographic space mission that totally changed our perceptions of the moon |url=https://www.redsharknews.com/this-1959-photographic-space-mission-totally-changed-our-perceptions-of-the-moon#:~:text=And%20it%20is%20film%20that%20will%20make%20Luna%203%E2%80%99s%20mission%20possible.%20Enemy%20film%20in%20fact,%20which%20the%20USSR%20recovered,%20unexposed,%20from%20a%20CIA%20spy%20balloon. |access-date=2025-01-02 |website=www.redsharknews.com |language=en}}</ref>{{sfn|Siddiqi|2018|pp=15–16}} The 200&nbsp;mm objective could image the full disk of the Moon and the 500&nbsp;mm could take an image of a region on the surface. The camera was fixed in the spacecraft and pointing was achieved by rotating the craft itself.

Luna 3 was the first successful three-axis stabilized spacecraft.  During most of the mission, the spacecraft was spin stabilized, but for photography of the Moon, the spacecraft oriented one axis toward the Sun and then a [[photocell]] was used to detect the Moon and orient the cameras toward it. Detection of the Moon signaled the camera cover to open and the photography sequence to start automatically.  The images alternated between both cameras during the sequence. After photography was complete, the film was moved to an on-board processor where it was developed, fixed, and dried. Commands from the Earth were then given to move the film into a [[flying-spot scanner]] where a spot produced by a [[cathode-ray tube]] was projected through the film onto a [[photomultiplier]]. The spot was scanned across the film and the photomultiplier converted the intensity of the light passing through the film into an electric signal which was transmitted to the Earth (via frequency-modulated analog video, similar to a facsimile). A frame could be scanned with a resolution of 1000 (horizontal) lines and the transmission could be done at a [[slow-scan television]] rate at large distances from the Earth and a faster rate at closer ranges.

The camera took 29 pictures over 40 minutes on 7 October 1959, from 03:30 UT to 04:10 UT at distances ranging from 63,500&nbsp;km to 66,700&nbsp;km above the surface, covering 70% of the lunar far side. Seventeen (some say twelve) of these frames were successfully transmitted back to the Earth (tracking stations in Crimea and Kamchatka), and six were published (frames numbered 26, 28, 29, 31, 32, and 35). They were the first photographs of the far hemisphere of the Moon.{{sfn|Siddiqi|2018|p=2}}

The imaging system was developed by P.F. Bratslavets and I.A. Rosselevich at the Leningrad Scientific Research Institute for Television and the returned images were processed and analyzed by Iu.N. Lipskii and his team at the Sternberg Astronomical Institute. The camera AFA-E1 was developed and manufactured by the KMZ factory ([[Krasnogorskiy Zavod|Krasnogorskiy Mekhanicheskiy Zavod]]).