Communications With Earth

Size and strength of the DSN antennas

The DSN antennas are extremely large:  34 meters (about 37 yards) and 70 meters (about 76 yards). These enormous antennas enable humans to reach out to spacecraft millions of miles away. The larger the antenna, the stronger the signal and greater the amount of information the antenna can send and receive. Each Mars Exploration Rover spacecraft carries multiple antennas used for different phases of the mission and allows it to communicate to multiple places and with other spacecraft at different speeds. The rover can choose to use four antennas: the UHF or the low-, medium-, and high-gain antennas. This capability gives the mission team several different ways to send commands and return data back to Earth.