Magnetometry plays a crucial role in a wide range of remote sensing applications. On Earth, it’s used for GPS-denied navigation, geological surveying, and submarine detection. For scientific missions in space, magnetometer-equipped spacecraft make measurements that help answer questions in the planetary science, Earth science, and Heliophysics communities. Typically, magnetometers are positioned on a long boom to minimize magnetic interference from other instruments and spacecraft subsystems. To ameliorate the formulation and implementation cost and reliability challenges associated with spacecraft booms, an appealing alternative approach is to use numerous small sensors on a shorter boom to perform gradiometry, to map and cancel self-induced magnetic noise [1]. To achieve this, new sensors with extremely low SWaP (size, weight, and power) and the ability to measure magnetic fields with absolute accuracy are required. Those would also allow for accommodation on small platforms like CubeSats, which enables new science. Here, we discuss different kinds of optically pumped quantum magnetometers based on spin defects in solid-state systems, focusing on silicon vacancy quantum center (VSi) in silicon carbide (SiC). The basic principle relies on maintaining resonance of the involved spin system, by compensating and thus measuring external fields using cancellation coils. This simple approach offers a robust technique for dual mode vector and scalar magnetometry. In this work: (1) We present different readout mechanisms [2] based on ODMR (optically detected magnetic resonance), EDMR (electrically detected magnetic resonance), and RFDMR (RF detected magnetic resonance). While ODMR shows higher sensitivity, EDMR offers a simpler, purely electrical approach that can be improved by optical pumping using UV light, improving EDMR sensitivity down to 30nT/√Hz. Additionally, we will discuss progress towards a novel approach with a hybrid version (RFDMR) based on a recently developed room-temperature maser using SiC [3,4]. This approach not only benefits from the advantages of each system—a narrow linewidth and an electrical readout—but also, due to the superradiance in the masing regime, allows us to narrow the linewidth beyond the state-of-the-art limit and use an electrical readout in a frequency range far above the noise of the modulation electronics. We show progress in SiC VSi defect engineering for magnetometer performance optimization, identifying the electron irradiation parameters leading to a sensitivity increase down to 40nT/√Hz. We also show challenges in excitation source stability, and the mitigation path leading to 1nT/√Hz with existing samples, as well as approaching sub-nT sensitivities by further irradiation granularity. Overall, the recent progress in advancing performance metrics of quantum solid state sensors, specifically magnetometers, as well as the maturing of operation modes leading to reduced complexity and resource consumption, shows that this technology field stays highly promising and exciting. Competitive single-digit nanotesla performance for planetary science is within reach. [1] Cochrane, C.J., Murphy, N., Raymond, C.A. et al. Magnetic Field Modeling and Visualization of the Europa Clipper Spacecraft. Space Sci Rev 219, 34 (2023) doi:10.1007/s11214-023-00974-y [2] A. Gottscholl, C.J. Cochrane, H. Kraus, Operation Modes of an Optically Pumped 6H-SiC Quantum/Solid State Magnetometer, IEEE Sensors (2024), doi:10.1109/JSEN.2024.3391191 [3] A. Gottscholl, M. Wagenhöfer, V. Baianov, V. Dyakonov, A. Sperlich, Room-Temperature Silicon Carbide Maser: Unveiling Quantum Amplification and Cooling, arXiv:2312.08251(2023) [4] A. Gottscholl, M. Wagenhöfer, M. Klimmer, S. Scherbel, C. Kasper, V. Baianov, G. V. Astakhov, V. Dyakonov, A. Sperlich, Superradiance of Spin Defects in Silicon Carbide for Maser Applications, Front. Photonics 3:886354. doi:10.3389/fphot.2022.886354