For the simulation, NASA used the software’s RF Module to model the microwave power penetration and attenuation into the soil (Figure 3). When the model was running without error, the physics of heating and heat flow were added. A transient analysis was used to determine heating as a function of time. (An AVI movie is available at http://science.nasa.gov/science-news/science-at-nasa/2009/07oct_microwave/ that shows lines of constant temperature as the heating progresses.)
Development of an early experiment payload for a lunar lander mission requires the specification of the microwave frequency, power, and method of delivery of power. Developing experiments with several different microwave frequencies would require a significant investment of resources, manpower, and time to perform experiments. COMSOL permits the calculation of microwave penetration and heating that could be expected with different experiment scenarios. This can reduce the time, labor, and cost to narrow the hardware requirements for the experiment.
This work was done by Dr. Edwin Ethridge of Marshall Space Flight Center using COMSOL Multiphysics software. For more information, visit http://info.hotims.com/28057-178.