RTEMS (Real-Time Executive for Multiprocessing Systems) has been selected as a possible ESA (European Space Agency) building block for space missions. As a first step to achieve the category of a building block, RTEMS must attain TRL (Technological Readiness Level) 6, which is equivalent to a product release in software engineering. TRL6 is achieved after the successful evaluation of the RTEMS technology, in this case, after the conclusion of RTEMS Improvement project. The full qualification of the technology will be achieved after the successful run of the operating system qualification process, with the space mission hardware and the application running on top of RTEMS, like control systems, telecommand or telemetry applications.
The paper can be found here.