The Relativistic Electron Atmospheric Loss CubeSat

REAL (Relativistic Electron Atmospheric Loss) is a CubeSat mission that will reveal different modes of atmospheric electron precipitation by characterizing the pitch angle and energy distributions of precipitating electrons. Significant progress has been made in identifying plasma waves that drive energetic electron precipitation (EEP) [e.g., Thorne, 2010 for review], however, our understanding of the physical modes of wave particle interactions is lacking. Electrons may be scattered slowly through a diffusive process [e.g., Shprits et al., 2008 review], or rapidly through nonlinear processes [e.g., Albert, 2000; Bortnik et al., 2008, Omura et al., 2015]. REAL will distinguish between these modes, and will investigate their relative importance. This presentation provides an update on the status of REAL. Notably, REAL was recently manifested on a launch in mid-2022 to a 555km sun-synchronous orbit, and integration and testing is ongoing. Once on orbit, REAL will make high time-resolution measurements of the electron pitch angle and energy distributions over a wide energy range, from 500 eV to 2 MeV. The 3U CubeSat incorporates low-, medium- and high-energy instrument heads, with 2, 5 and 4 look-directions respectively, making use of advances in sensor miniaturization. It operates in low Earth orbit (LEO), ideal for measuring precipitation since the atmospheric loss cone is larger (~60 deg) than at the equator (few degrees), with time resolution sufficient to resolve electron microbursts. The pitch-angle resolved measurements will also distinguish between precipitating, quasi- trapped, and trapped populations, thus more accurately quantifying the electron loss rate and the impact on Earths atmosphere.