TY - RPRT TI - Electron-bombardment thrusters using liquid- mercury cathodes. AU - Eckhardt, W. O. AU - King, H. J. AU - Knechtli, R. C. AU - Ward, J. W. PY - 1967 UR - https://ntrs.nasa.gov/citations/19670048093 ID - 19670048093 ER -