This comment below this answer to How was it possible for the Apollo 11 to film and take pictures with such radiation? links to the svengrahn.pp.se post Luna 3 - the first view of the moon's far side.

It shows the annotated image below of Luna-3. The image is a partial cut-away view, the lower half shows the external area and the upper half shows some of the internal components I believe.

Near the "bottom" of the spacecraft (the end with the Pivoting antennas and Lunar sensors) there is something labeled "Cover of illuminator".

Question: What did Luna 3's illuminator illuminate and why did it need a cover?

One of the origins of Luna-3 was the work by Boris Raushenbakh on attitude control started in 1955 in the NII-1 rocket research institute of the Ministry of Aviation. This work was co-ordinated with Korolev's design bureau and had as its goal stabilised photo-reconnaissance satellites. Raushenbakh's group was contracted by the lunar project section Korolev's design bureau OKB-1 to design the attitude control for the E-2 variant of lunar exploration craft intended to image the Moon's hidden side. The manager of the lunar probe project at OKB-1 was Gleb Maksimov. An excellent account of these early Soviet lunar missions can be found in (4) and (14). A cutaway sketch of the space probe with a Soviet-era translation of Russian captions added is shown below.

4Asif A. Siddiqi, "First to the Moon", Journal of the British Interplanetary Society, Vol.51, pp.231-238, 1998.

14Timothy Varfolomeyev, Journal of the British Interplanetary Society, Vol.52, pp.157-160, 1999.

click for full size

Luna-3 from svengrahn.pp.se

  • $\begingroup$ companion question: How did Luna 3's pivoting antennas and ribbon antennas work? $\endgroup$
    – uhoh
    Commented Sep 20, 2019 at 3:07
  • 4
    $\begingroup$ Soviet Robots in the Solar System by Huntress and Marov has a less detailed drawing but it lists no illuminator. It shows the flat surface at the left of this image to be an optical window that the film camera shot through. These covers may be for that window and there may be translation problems. $\endgroup$ Commented Sep 20, 2019 at 3:40
  • 3
    $\begingroup$ @OrganicMarble absolutely right. "On October 7, “Luna-3” entered a portion of the orbit on which there was a “full moon” for it. Then the porthole lid opened, behind which there were two cameras with a focal length of 200 and 500 mm and shooting began." $\endgroup$
    – A. Rumlin
    Commented Sep 20, 2019 at 5:13

1 Answer 1


That appears to be a translation error.

This picture (figure 6.8) from Soviet Robots in the Solar System by Wesley T. Huntress, JR. and Mikhail Ya Marov shows that the flat surface at the left of the image in the question is an optical window. There are two semicircular aperture covers (shown open in the picture) which are labeled 'cover of illuminator' in the question picture.

enter image description here

I suppose you could call it an 'illuminator' since when the covers are open, the window allows light in to the film camera package behind it. In the question picture, the camera package is labeled 'lunar sensors'.

For the 'why' part of the question, I can only assume that the aperture covers were to protect the optical window during launch and separation.

Note: There is a discrepancy between this photograph and other photographs and drawings in the book. The picture in the question matches the other drawings. Namely, the orientation of the "belt" of solar panels is reversed in this photograph, as if the solar panel belt had been slipped off, flipped 180 degrees, and slid back onto the spacecraft.

  • $\begingroup$ Okay, this is a much better view, thanks! $\endgroup$
    – uhoh
    Commented Sep 20, 2019 at 12:53
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    $\begingroup$ Yes, it's a mistranslation. In Russian, "иллюминатор" (illyuminator) means a porthole (in the sense of a window, not a cannon opening). $\endgroup$
    – Litho
    Commented Sep 20, 2019 at 13:21
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    $\begingroup$ There is a wonderful book/film called "Everything is Illuminated" in which 'translating' Russian words one by one leads to the title phrase (to mean "everything is clear now")! rogerebert.com/reviews/everything-is-illuminated-2005 $\endgroup$ Commented Sep 20, 2019 at 13:32
  • $\begingroup$ @user2705196 thanks for the reference, I remember enjoying the film very much in the theatre back then. $\endgroup$
    – uhoh
    Commented Sep 20, 2019 at 23:22

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