To send and receive data, orbiting spacecraft depend on radio-frequency communications. It's been this way since the 1957 launch of Sputnik 1, which made use of two radio frequencies: 20.005 and 40.01 MHz. The United States' first satellite, Explorer 1, had beacons for the frequencies 108.00 and 108.03 MHz. Space communication nowadays borrows a huge swath of the radio spectrum for all sorts of competing purposes, from weather satellite imagery to GPS to television broadcasts.

Read More at www.motherboard.vice.com