Light metal Hall thruster technology may enhance many critical DoD and commercial missions such as satellite orbit maintenance, orbit raising and repositioning. Magnesium offers the possibility of efficiencies close to xenon with the possibility of lightweight, long term, low maintenance, solid propellant storage. High pressure propellant tanks will not be required and spacecraft interaction issues should be manageable. Mg Hall thrusters could also form one half of a multi-mode propulsion system that also contains a Mg based rocket. This system would provide both high thrust and high Isp. The two systems would share propellant feed system components, tanks, and fuel. Magnesium Hall thrusters are attractive for NASA Flagship, Frontier, and Discovery class missions because Isp ~ 5000 s is possible at low voltage, enabling the use of low cost flight qualified power processors. These thrusters can also be deeply throttled. Examples mission targets include asteroids, comets, and the outer planets. Sample return missions are also enabled. Magnesium thrusters are also well suited for lunar and Martian missions. A high power cluster would support manned missions by transporting fuel and cargo. In-situ propellant utilization is possible, as is a multi-mode system incorporating a Mg based rocket. Advantages over SOA noble gas Hall thrusters include higher Isp at the same voltage, less erosion (longer lifetime) at the same Isp and power, and much lower propellant, propellant storage, and tests costs. High pressure propellant tanks will not be required. Vapor pressure curves suggest modest precautions may fully mitigate spacecraft interactions. The powdered feed system technology may also be used to develop powdered metal propellants such as Mg and Al to bipropellant rockets.