A method for protecting communications between an aircraft and a spacecraft in outer space including flying the aircraft in the earth's atmosphere at an altitude above 40,000 feet from the earth, and preferably above 50,000 feet, and transmitting a signal from the aircraft to the spacecraft having a frequency within a range of 50-70 GHz. The method includes selecting the frequency of the signal based on the altitude of the aircraft and the elevation angle between the spacecraft the aircraft.