Karvel Reaches TRL-9: Flight-Proven Aboard ATHENE-1

Karvel, Critical Software's on-board software platform for spacecraft, has reached Technology Readiness Level 9 (TRL-9), the highest level on the scale. The milestone follows Karvel's flight aboard ATHENE-1, a small satellite in low Earth orbit and the main mission of the SeRANIS research program led by the University of the Bundeswehr Munich. 

On ATHENE-1, Karvel runs across multiple on-board systems. That gives spacecraft teams what matters most when choosing flight software: evidence that it works in space, not only in the lab. 

TRL-9 means flight-proven: the technology has been demonstrated in its final form, in its real operating environment, during an actual mission. For space software, that environment is orbit, with its radiation, tight timing, and no chance of a quick fix on the bench. 

Lower levels show that software works in testing. TRL-9 shows it works when it counts. For mission teams, that evidence reduces technical risk and makes Karvel a safer foundation to build on. 

Karvel offers civil, defense and commercial spacecraft developers a faster, lower-risk path to mission-ready on-board software. Teams interested in building on Karvel can request a technical demo.

Karvel is a modular on-board software platform and SDK that lets spacecraft teams build, verify, and qualify mission software without starting from scratch. Instead of rebuilding OS integration, communication protocols, tooling, and verification for every mission, teams build on a proven foundation and focus on mission logic. 

The platform combines hardware and OS abstraction layers, pre-validated components aligned with space standards such as CCSDS and ECSS, and an SDK with development, simulation, and verification tooling. It supports operating systems including RTEMS, VxWorks, FreeRTOS, MOSA.ic, Zephyr, and Linux. 

Karvel builds on Critical Software’s space heritage, which dates to 1998, when NASA became the company’s first client. Since then, Critical Software has supported more than 30 space programs across institutional, defense, and commercial missions. 

Critical Software’s mission remains the same: to build better and build safer. Our software and systems not only advance capabilities in orbit but also give our partners the confidence that their work will succeed — safely, reliably, and sustainably. 

To learn more about our work in the space sector, from flight software to verification and validation, visit our Space & Science page.