A Beam Induced Upset during the Flight of the ECHO-7 Rocket

During the flight of the ECHO-7 rocket, electron beams with energies and currents up to 40 keV and 250 mA were emitted at pitch angles controlled by a deflection magnet and successfully detected upon reflection in the southern ionosphere. Three anomalies occurred onboard the beam emitting main payload, one of which is presented in detail. while emitting at 36 keV and 180 mA and with the deflection magnet turned off, the vehicle potential was measured to be greater than 5 kV. During a 30 ms pulse of gas from the attitude control system the vehicle rapidly discharged, a power converter for several diagnostic sensors failed and a safety circuit was activated to shut the electron beam off. Two qualitative models of the consequences of ionization of the neutral cloud by beam and return current electrons are examined. An understanding of the interactions of neutral gas clouds with charged vehicles is of capital importance for the design of reliable high-power space platforms.