Beerden, YarneYarneBeerdenCarmans, BooBooCarmansVandebosch, RemyRemyVandeboschHendrikx, DriesDriesHendrikxBammens, SamSamBammensAydogan, MusaMusaAydoganAchten, SiemenSiemenAchtenGorissen, JeffreyJeffreyGorissenVanspauwen, SebastiaanSebastiaanVanspauwenVandervoort, SiemenSiemenVandervoortMannaerts, JensJensMannaertsJacobs, StijnStijnJacobsBox, DaphneDaphneBoxNesladek, MilosMilosNesladekHruby, JaroslavJaroslavHruby2026-08-312026-08-3120262331-7019https://imec-publications.be/handle/20.500.12860/60163Precise mapping of the geomagnetic field is essential for understanding Earth’s geodynamics, space weather interactions, and navigation applications. Traditional magnetometers face limitations in sensitivity for a wide dynamic range, and compactness. To address these challenges, the OSCAR-QUBE quantum magnetometer based on nitrogen-vacancy centers in diamond was developed, providing a sensitive and compact solution for space-based magnetic-field measurements. Our system employs optically detected magnetic resonance to measure magnetic fields utilizing the quantum properties of nitrogen-vacancy centers in a miniaturized design. The form factor of the final device was 1U (10 ×10 ×10 cm3), weighing 420 g, and had a power consumption of 5 W. Deployed aboard the International Space Station, our magnetometer measured high-resolution magnetic-field maps, achieving a sensitivity of <300 nT/√Hz and successfully demonstrating in situ vector magnetic-field mapping under low-Earth-orbit conditions. These results validate the flight-proven application of diamond quantum sensing in space, demonstrating the feasibility of solid-state quantum magnetometry for next-generation remote sensing and Earth observation missions. This work lays the foundation for future compact, multisensor quantum payloads for both scientific and commercial space applications.engJournal article10.1103/483m-8hfcWOS:001767876600001SWARM