Kvant and FSM clipart

The streamlined fairing covering the aft end of the FSM (right) pointed upwards at liftoff, and formed the nose of the launch stack. Probably the “purest” space tug of the Soviet/Russian program was the Kvant Functional Service Module (FSM) (figure 3-14). The FSM was a stripped-down FGB. Presumably it was thus launched “tail-up” like the TKS spacecraft, an idea supported by the streamlined structure covering the FSM’s aft, where the Merkur capsule would be located on a TKS. It was launched docked with Kvant’s aft port on March 31, 1987. This would have placed the Kvant module with the probe docking unit meant to attach it to Mir pointed downwards at launch, against the top of the Proton booster.