 NASA Rocket Mission Studying Escaping Radio Waves by National Aeronautics and Space Administration

Official VIPER mission description: www.nasa.gov/missions/sounding-rockets/nasa-rocket-mission-studying-escaping-radio-waves/

The mission account describes low-frequency ionospheric absorption/reflection and condition-dependent leakage into the magnetosphere, with measurements below, within and above the relevant layers. It supports a propagation qualification, not a universal claim that all low-frequency electromagnetic signals are blocked.