Communicating with space probes
Communicating with something over 11.2 billion kilometres (7 billion miles) away is no mean feat, and requires a worldwide network of huge radio antennas. Stations in California, Spain and Australia form the Deep Space Network (DSN) – strategically spread out to ensure there will always be one antenna that can point at any space probe.
Likewise, space probes – like Pioneer 10 and 11 launched in the early-Seventies – need antennas to send pictures, weather data and heading information as radio waves. However power constraints mean that space probes can only send very weak signals, which get weaker the farther away they travel. Antennas on the ground have large dishes to capture the signal, yet greater amplification and noise reduction is needed to boost the signal to a readable level.