Copyright © 2014 by John E. Brandenburg. Published by The Mars Society with permission 






Dr. John E. Brandenburg PhD

Morningstar Applied Physics LLC 




A rapid, cost effective and sustainable human mission to Mars should take maximum advantage of the Mars system resources, new heavy lift boosters and advances in SEP(Solar Electric Propulsion) vehicles. To make such an effort sustainable over many Presidential administrations, an early human foothold should be established on Phobos, Mars innermost moon, as a “base camp” and the Mars surface mission should be staged from there. Due to controversial aspects of nuclear propulsion, an early Mars mission should not make use of nuclear propulsion. Chemical boosters, such as Falcon Heavy, or SLS, boosted by SEP upper stages should be the basic propulsion.  It is  proposed in this architecture that high power Solar Electric propulsion based around the MET (Microwave Electro-Thermal) thruster(1,2) with water propellant used as an upper stage for a heavy lift chemical booster, will allow a 30 Metric Ton basic payload package to be sent to Phobos to establish a base there.  The MET has Isp of 900seconds using water, higher thrust than higher Isp SEP systems, and can take advantage of the Oberth Effect (3) when boosted out of LEO to escape velocity.  Recent successful operation of the water-MET at 75kW using 915MHz microwaves will be discussed.


1.     Brandenburg, J.E. Kline, J.F., and Sullivan D.F. (2005) “The Microwave Electro-Thermal (MET) Thruster Using Water As Propellant” IEEE Transactions On Plasma Science, Vol.  33, No. 2. p776.

2.     Brandenburg, J.E., John F. Kline, Ronald Cohen, and Kevin Diamante.  (2001), “Solaris: A Low Cost Human Mars Mission Architecture Based on Solar Electric Propulsion” Proceedings of the 2001 Mars Society Symposium at Stanford University.

3.     Ways to Spaceflight, NASA TT F-622, translation of "Wege zur Raumschiffahrt," R. Oldenbourg Verlag, Munich- Berlin, 1929