Authors: Niharika Godbole (American University, NASA GSFC), Steve Christe (NASA GSFC), Elliad Peretz (NASA GSFC), Natasha Jeffreys (Northumbria University), Daniel Ryan (University of Applied Sciences and Arts Northwestern Switzerland), Laura Hayes (NASA GSFC), Kyle Gregory (NASA GSFC), Amir Caspi (Southwest Research Institute), Sam Krucker (ZTH Zurich), Kelsey Gilchrist (NASA GSFC), Juan C. Martinez Oliveros (UC Berkeley Space Sciences Laboratory), Pascal Saint-Hilaire (UC Berkeley Space Sciences Laboratory), Olivier Limousin (CEA Paris-Saclay), Aline Meuris (CEA Paris-Saclay), Abel Vanel (CEA Paris-Saclay), Hugo Allaire (CEA Paris-Saclay), Negeen Saghafi (NASA GSFC), Ryan Boggs (NASA GSFC), Teresa Tatoli (NASA GSFC), Mathew Reeves, Traci Rosnack (NASA GSFC), and the PADRE Team

The Measuring Directivity to Determine Electron Anisotropy (MeDDEA) instrument is being developed at NASA Goddard Space Flight Center for flight on the solar Hard X-Ray (HXR) Polarization And Directivity x-Ray Experiment (PADRE) CubeSat observatory. Measurements from MeDDEA will provide a better understanding of the acceleration and transport process(es) that occur in solar flares (or related solar events), in order to address the following science questions:

1. How is magnetic energy previously stored in the solar corona converted into kinetic energy of charged particles during a solar flare?

2. What is the anisotropy of the electrons that produce the observed HXR emissions?

To accomplish this, MeDDEA, in conjunction with the Spectrometer Telescope for Imaging X-rays (STIX) on Solar Orbiter (SO), will observe the Sun with cross-calibrated detectors to make the first measurements of XR anisotropy from solar flares. This will allow accurate constraint of their associated electron angular distributions. Moreover, XR polarization measurements made by the Solar HARd x-ray Polarimeter (SHARP) instrument, also on PADRE, provide a complimentary approach to this same problem. PADRE is expected to launch in mid-2025.