Soyuz 7K-VI Zvezda

The Soyuz 7K-VI Zvezda. This was a 1960s proposal for a militarized Soyuz spacecraft, something to compete with the USAF's MOL concept.

The 7K-VI differed in many ways from the baseline 7K-OK Soyuz. The descent module was at the front of the stack, instead of behind the orbital module like on the standard Soyuz. The orbital module itself was much bigger, and was outfitted with recon equipment.

Instead of solar panels, the 7K-VI carried two nuclear generators. Solar panels were seen as being too easily damaged and would put constraints on maneuvering the spacecraft. Orienting the panels to get maximum electrical power would have been impractical in a combat situation.

Other military equipment included two long direction finding antennas and a modified R-23 autocannon. You can see it on the front part of the orbital module between the two antennas. The cosmonauts would have had to orient the whole ship to aim the cannon.

The project never came to fruition, with the military focusing instead on the Almaz space station. The R-23 did fly in space and was test fired on Salyut 3.