Implementing space separation functionality into Linux-based spacecraft computer

European Space Agency (ESA) has recognized Integrated Modular Avionics (IMA) and ARINC specification 653 (ARINC 653) as a reference avionics computer for space application. IMA reduces the space by integrating a system composed of many electronic devices into a computer. Recent researches have been studying how to apply the ARINC 653 into an open source operating system, such as Linux. These studies have concentrated on partition scheduling for time separation. However, requirements to guarantee spatial separation should be further analyzed to ensure deterministic execution time. This research proposes a method to accomplish spatial isolation for the ARINC 653 specification in Linux. Memory management is modified to improve spatial isolation. We have added new spatial separation functions. They are used during the partition startup process. A partition memory monitor is implemented to analyze spatial separation. The proposed method was evaluated on the LEON4 processor, which is the next generation microprocessor to be used in the future space missions. All implementations confirm that spatial isolation of the ARINC 653 specification was accomplished and provided memory to partitions efficiently.