This was a fascinating read. It’s funny to think that 50 years ago western engineers would’ve been very interested in reverse engineering this unit, whereas nowadays it’s purely for historical interest.

It’s also interesting that its limitations were being felt fairly quickly and the cosmonauts were pushing for a replacement but that didn’t come until 2002. I suspect that’s a reflection of the financial situation of the Soviet space program in the 1970s and especially the 1980s, and then the dissolution of the Soviet Union.

Why didn't they add just a bit more mechanics, so it could adjust it's own speed when in elliptical orbits? It doesn't seem hard, but you'd think they would have done it if it was doable. Especially with the cosmonauts complaining.

Can someone explain the 2 longitude cams to me? I don't quite grok it as described.