As written by Aurovrata
Plesetsk is actually ideally situated to launch satellites into
Molniya orbits, and as a result saw many more launches than Baikonour.
A or better THE molniya orbit has an inclination of 63.4°.
The lauchpades are located about 62.9° N.
So launching nearly straight east (which gives you the maximum input from ...
According to this source (in Russian), out of seven successful Salyut stations (amongst which were the three military Almaz stations) the modified NR-23 cannon was installed only on Salyut-3 (aka Almaz-2):
The only prototype of such an installation was mounted at the Almaz-2 station, also known as Salyut-3.
The above statement indirectly assumes that MIR ...