I have tried searching for answers to these questions but i cant seem to find them, so if anyone could help me it would be greatly appreciated. How efficiently you can reflect microwaves? I know visible light can be reflected at 99.99% efficiency or something ridiculous like that, is it the same for microwaves? Also, how much are microwaves absorbed as they pass through the atmosphere? I havent been able to find any exact figures. Finally, does anyone know what is the most powerful continuous-wave maser that's been made?