How scientists keep tabs on spacecraft as they journey into the vast expanse of the universe
DID YOU KNOW? The DSN received and replayed the first images of Neil Armstrong walking on the Moon in 1969
There are thousands of satellites and spacecraft whizzing around in the Solar System. But how do scientists communicate with them? This job largely belongs to the Deep Space Network (DSN), a complex array of giant radio antennae that canvas the cosmos to stay connected with spacecraft. Operated by NASA’s Jet Propulsion Laboratory (JPL), the DSN has been around since 1958, when radio tracking stations were installed in Nigeria, Singapore and California. In its debut mission, the network of dish-shaped antennae helped Earth-based controllers guide Explorer 1, the first military satellite, into orbit. Now the DSN is made up of 14 dish antennae at three stations that are spread 120 degrees apart around the globe – in Australia, the United States and Spain. Together, these sites completely cover the night sky, ready to exchange signals with spacecraft from anywhere in the Solar System – or beyond.
Did you know? Over 300 robotic spacecraft have left Earth orbit
Each station is equipped with one 70-metrewide dish and several smaller supporting 34-metre and 26-metre antennae. The latest addition to the DSN family, DSS 56, was switched online in 2021. The 34-metre-wide dish, constructed in Madrid, joined the five other dishes at the Spanish station, and is used to manage data between the full catalogue of NASA spacecraft, including the James Webb Space Telescope, and future crewed missions to the Moon.
To communicate with far-flung spacecraft, the DSN uses radio waves to transmit instructions and information, as well as to receive them, known as uplink and downlink. Radio waves are used to transmit information at the speed of light – around 186,000 miles per hour – but due to the vast expanse of the Solar System, it can still take several hours for some signals to reach their targets.
The record for the most distant deep-space communication is between the DSN and the Voyager 1 spacecraft, which launched in September 1977. Originally designed to explore and examine the gas-giant planets Jupiter and Saturn, the spacecraft now ventures beyond the Solar System in interstellar space, around 15.2 billion miles aw
