OPS-SAT is an in-orbit laboratory mission designed to allow experimenters todeploy new on-board software and perform in-orbit demonstrations of new tech-nology and concepts related to mission operations. The NanoSat MO Frame-work facilitates the process of developing experimental on-board software for OPS-SAT by abstracting the complexities related to communication across the space toground link as well as the details of low-level device access. The objective of thisproject is to implement functional simulation models of OPS-SAT peripherals andorbit/attitude behavior, which integrated together with the NanoSat MO Frame-work provide a sufficiently realistic runtime environment for OPS-SAT on-boardsoftware experiment development. Essentially, the simulator exposes communi-cation interfaces for executing commands which affect the payload instrumentsand/or retrieve science data and telemetry. The commands can be run either fromthe MO Framework or manually, from an intuitive GUI which performs syntaxcheck. In this case, the output will be displayed for advanced debugging. The endresult of the thesis work is a virtual machine which has all the tools installed todevelop cutting edge technology space applications.