Low Mass 20 kW Hall Thruster

To meet DoD requirements for high power Hall thruster technologies that significantly improve operating characteristics and reduce life cycle costs, Busek proposes to develop a very low-mass, 20-kW class Hall thruster suitable for a wide range of missionsin Earth orbit. The design benefits from a unique magnetic circuit. The predicted mass of the magnetic structure and coil is about half that of a conventional design. Thrust efficiencies in excess of 65% are predicted. Electromagnetic emissions mayalso be low. The design is especially suitable for clustering because of the proposed magnetic arrangement. In Phase I, Busek will generate mechanical drawings, build a 20-kW prototype, measure its magnetic field on the bench, and measure the thrust itproduces at nominal operating conditions. In the first half of Phase II, the lab prototype will be subjected to a more extensive series of tests to demonstrate bimodal capabilities. Plasma simulations and erosion measurements would validate the predictedlifetime, which is >10,000 hours. Plume testing would include measurements of ion current, ion energy distribution, and doubly charged ions. In the second half of Phase II, an engineering model low-mass 20-kW will be developed, tested, and delivered.The Phase I program will give Busek an extremely low mass, long life axisymmetric Hall thruster suitable for operation alone or for clustering. Once developed into a flight thruster, this can be marketed commercially for all types of high power EPmissions involving station-keeping, repositioning, and orbit transfer.Busek plans to develop the engineering model into a commercial product. The low mass of this thruster with respect to other designs will make it the product of choice for high power missions experiencing mass constraints. The thruster can function aloneor in a simple cluster. Reasonably sized clusters could fulfill mission needs anywhere from 20-kW to 200-kW. DoD applications such as space based radar and a space tug would directly benefit. Fast orbit transfer of high-power communications andsurveillance satellites would also be enabled.NASA planners envision many missions requiring high Isp propulsion systems rated at hundreds of kilowatts and even megawatts. For these missions, long lifetime is crucial. Due to ground testing constraints, spacecraft architectures, and reliability andredundancy issues, a multiple thruster approach makes sense. The lightweight, 20-kW thruster will be ideal for many of these missions, such as a NEP system for missions to the outer planets, LEO to GEO transfer of