A team sponsored by NASA is revolutionizing the measurement of magnetic fields by creating a novel system that can conduct scientific measurements and provide spacecraft attitude control functions. This innovative system is compact, lightweight, and can be integrated onboard spacecraft, eliminating the need for the typically required boom structure to measure Earth's magnetic field. This advancement enables smaller, more cost-effective spacecraft to take these crucial measurements. Moreover, this system has the potential to replace standard attitude control systems in future Earth-orbiting spacecraft, allowing them to contribute to vital global measurements that help us comprehend how Earth's magnetic field shields us from hazardous solar particles.

Solar storms drive space weather that poses a threat to various assets in space and can disrupt Earth's upper atmosphere, impacting communication and power grids. Fortunately, Earth's magnetic field provides protection by channeling much of the energy into the north and south poles, resulting in the creation of aurorae. These aurorae showcase the electromagnetic energy and currents flowing through Earth's space environment, often exhibiting small-scale magnetic features that influence the overall energy flow. Observing these minute details necessitates multiple simultaneous observations across a wide range of spatial and temporal scales, a task that can be accomplished by constellations of small spacecraft.

To facilitate such constellations, NASA is developing an innovative hybrid magnetometer capable of conducting both direct current (DC) and alternating current (AC) magnetic measurements while being embedded in the spacecraft's attitude determination and control system (ADCS). High-performance, low SWAP+C (size, weight, power, and cost) instruments are essential, along with the ability to manufacture and test a large number of these instruments within a standard flight build schedule. Future commercial or scientific satellites could leverage these compact, lightweight embedded hybrid magnetometers to gather the types of measurements that will enhance our understanding of space weather and Earth's magnetic field response to solar storms.

Traditionally, it has been challenging to obtain research-quality DC and AC magnetic measurements using sensors within an ADCS due to the proximity to contaminating magnetic noise sources, such as magnetic torque rods. Previous missions that incorporated both DC and AC magnetometers placed them on lengthy booms pointing in opposite directions from the satellite to keep the sensors as far apart from each other and the spacecraft as possible. Additionally, the typical magnetometer used by an ADCS lacks the sampling speed necessary to capture the high-frequency signals required for magnetic field observations.

A team at the University of Michigan, sponsored by NASA, is developing a groundbreaking hybrid magnetometer and attitude determination and control system (HyMag-ADCS) that is a single, low-SWAP package capable of integration into a spacecraft without the need for booms. The HyMag-ADCS comprises a three-axis search coil AC magnetometer and a three-axis Quad-Mag DC magnetometer. The Quad-Mag DC magnetometer employs machine learning to enable boomless DC magnetometry, while the hybrid search-coil AC magnetometer includes attitude determination torque rods to facilitate both ADCS functions and scientific measurements.

The HyMag-ADCS team is incorporating various technologies into the system to ensure its success:

• Quad-Mag Hardware: The Quad-Mag DC magnetometer consists of four magneto-inductive magnetometers and a space-qualified micro-controller mounted on a single CubeSat form factor printed circuit board. Combining multiple sensors on a single board enhances the instrument's sensitivity and enables noise identification on small satellites, crucial for science-grade magnetometer sensing.
• Dual-use Electromagnetic Rods: By utilizing search coil electronics and torque rod electronics in a novel manner, the HyMag-ADCS system can employ electromagnetic rods for both attitude determination and scientific measurements.
• Machine Learning Algorithms for Spacecraft Noise Identification: The team is developing advanced algorithms to autonomously eliminate noise generated by the spacecraft, including the Unsupervised Blind Source Separation (UBSS) algorithm and the Wavelet Adaptive Interference Cancellation for Underdetermined Platforms (WAIC-UP) method.

The HyMag-ADCS system is currently in the early stages of development, with a complete engineering design unit in progress. The project is primarily carried out by undergraduate and graduate students, providing them with valuable hands-on experience in preparation for future careers in science and engineering.

For more information, visit the project entry on NASA TechPort.

Project Lead: Prof. Mark Moldwin, University of Michigan

Sponsoring Organization: NASA Heliophysics Division's Heliophysics Technology and Instrument Development for Science (H-TIDeS) program.