Mars and lunar cargo missions, and the upcoming Juno mission to Jupiter. Also, piloted interplanetary missions become feasible with sufficient cathode output and life. Earth transfer, stationkeeping and earth escape would occur at less cost, size and mass. Improved conventional reservoir cathodes, following from this effort, are needed in linear beam amplifiers to increase data rates in space communications. Output power, life, bandwidth, and frequency will all improve with better cathodes. These devices include traveling wave tubes and klystrons.