Computer resources on military and telecommunications satellites are being over-tasked more than ever before, and the increasing shift to onboard signal processing will only compound the problem in the future. Space-based multiprocessor computer systems linked by high speed interconnect networks offer one possible solution to this ever expanding problem. Gallium arsenide (GaAs) integrated circuits using metal-semiconductor field effect transistors (MESFETs) offer very high speed operation, reduced power consumption, and inherent radiation tolerance, which make them ideally suited to the harsh space environment. The design, simulation and layout of an 8 x 8 non-blocking crosspoint switch implemented in GaAs two-phase dynamic FET logic (TDFL) is presented in this thesis. The design of the TDFL crosspoint switch given here is a modification of a crosspoint switch design that uses GaAs direct-coupled FET logic (DCFL). Design specifics of working with GaAs are presented first, followed by detailed descriptions of the DCFL and TDFL crosspoint switches, and finally, an analysis of the advantages and disadvantages of dynamic logic over static logic is presented. The TDFL crosspoint switch presented here could easily be modified to serve as a one gigabit per second serial interconnect for future space-based multiprocessor computer systems.