ELFIN Mission Operations and ADCS Design

Abstract

The Electron Loss and Fields INvestigation (ELFIN) mission comprises of two 3U+ space weather CubeSats developed, built, and operated by several generations of undergraduate students at UCLA. These CubeSats uniquely spin at 21 RPM and are designed to produce novel measurements of precipitating, trapped, and reflected populations of electrons and ions in the radiation belts. ELFIN was on orbit for four successful years before deorbiting in September 2022. It is now recognized as one of the most scientifically productive CubeSats in the NASA and NSF CubeSat fleet with over 40 refereed scientific publications in less than 3 years. However, ELFIN mission operations had a challenging start and only became successful after a complete refactor of the mission's operational paradigm in early-2020. The refactor yielded significantly higher data downlink volume, minimized human error, and required far fewer hours on console. This was achieved not by automating satellite operations, but rather by defining a set of abstractions with rigid rules. We present this new operational framework (including implementation of our onboard flight software and Attitude Determination and Control System (ADCS) design) that allowed a small team of students to achieve reliable daily operations for two satellites. Strategies implemented here are designed with the idea of scaling to multi-satellite operations of science observatory missions. Finally, we will highlight the scientific progress enabled by these new ELFIN data sets, which emphasize the role of electron precipitation measurements for future studies in magnetospheric, ionospheric, and atmospheric physics.