This paper presents the design of a VHSIC multimode tracker being developed for the US Army Missile Command that will interface with imaging infrared (IIR) sensors implementing DOD-developed Phase I VHSIC devices. The system is being initially configured for demonstration testing with MDAC's Mast-Mounted Sight system which uses a common module FLIR and with a second generation IIR seeker for the Hellfire Fire and Forget Missile. Requirements for the VHSIC processor are discussed and the architecture presented as derived from the requirements. This design incorporates array processors, 1750A processor, and a three-level processor-to-processor interconnection network into a modular design that can be scaled to match performance and size/form factors to meet acquisition sight and seeker implementations. A multimode algorithm tracker includes parallel calculations of spatial correlation, centroid, and conformal gate for target tracking. The control software provides an environment for multitarget tracking. A field test program will evaluate the VHSIC tracker interfaced with the Mast Mounted Sight thermal imaging sensor in 1988. A captive flight testing of an advanced IIR seeker is planned at MICOM in the fall of 1988.