Satellites have limited power budgets due to the amount of power collected by the satellites solar panels. The goal is to have a wide range of functionality, while running off a limited power source. Large microprocessors use large amounts of power to report back temperature and chemical sensor data to ground stations. By using small microcontrollers to perform the data collection and minimizing the usage of the larger microprocessors, the satellites will save power. A prototype design of the Microdot 4-bit microcontroller for space applications is presented. Requirements for the Microdot, such as microwatt power consumption and 23 different instructions, are based on research completed at AFRL/VSSE, Air Force Research Laboratory at Kirtland AFB, NM. A brief history of 4-bit microcontrollers and microprocessors, the synchronous design methodologies used, and space-based integrated circuit issues are presented. Various CAD tools were used, implementing both standard cell and full custom logic into the design. The prototype Microdot was fabricated at TSMC using MOSIS to validate the design implementation. Results from high fidelity simulations indicate the Microdot design has a power consumption of 16.3 mW operating at I kHz and consumes 22 mW when operating at the maximum operating clock frequency of 20 MHz. These results indicate that the Microdot can be implemented into space-based systems, while exhibiting low power usage.