Interim Control Module

The Interim Control Module (ICM) was a NASA constructed module to serve as a temporary "tug" for the ISS in case the ISS Zvezda service module was destroyed or not launched for an extended period of time. It was derived from a formerly-classified Titan Launch Dispenser used to distribute reconnasance satelites to different orbits. It would have been able to prolong the lifespan of the Zarya module by providing equivelent propulsion capabilities to the Service Module, although not any of the other life support capabilities.

It was not needed, so it's current location and status is uncertain.