The Earth Exploration Satellite Service requires a scientifically determined set of microwave frequency bands in which passive remote sensing of the Earth's surface and atmosphere can be performed. Those bands are defined by the physical laws of the atmosphere and are one of the Earth's important natural resources. However, due to the inflation of the civil and military needs (mobile phones, TV, Internet, radar on cars etc.), many areas of the microwave spectrum could become useless for passive microwave measurements. The reason for this is man-made interference which can render a passive sensing frequency band utterly useless either from in-band or out-of-band emissions. The World Meteorological Organisation (WMO), together with most of the space agencies around the world, has defined an extensive list of frequency bands that need to be forever protected known as the "Do or Die" list. This list does not duplicate the frequency needs for any given use. It's the minimum set of bands to monitor the Earth's environment, including weather forecasts, hydrology and global change among other vital applications.