What is the Deep Space Network?
The Deep Space Network (DSN) is NASA's global system of giant radio antennas — three sites in Goldstone (California), Madrid (Spain) and Canberra (Australia), spaced ~120° apart so that any spacecraft is always above one site's horizon as Earth rotates. It is the only link humanity has with probes like Voyager 1 and New Horizons.
Whispers across 25 billion kilometres
Voyager 1's transmitter runs on about 20 watts — a refrigerator lightbulb. After travelling more than 25 billion km, its signal reaches Earth at less than a billionth of a billionth of a watt. The DSN's 70-metre dishes and ultra-cold amplifiers recover data from that whisper at a few dozen bits per second.
A one-way message to Voyager 1 currently takes over 23 hours at the speed of light. Every command is planned days ahead — there is no 'undo'.
Why three sites
Earth rotates, so a single antenna would lose sight of a probe for two-thirds of the day. With stations in California, Spain and Australia, at least one dish can always point at any spacecraft. You can see what each antenna is talking to right now on NASA's public 'DSN Now' dashboard.
Where the probes are tonight
Cosmik shows the live positions and distances of Voyager 1, Voyager 2, Pioneer 10 and New Horizons at the rim of the solar system view — click any probe label for its story. Distances update live from NASA JPL Horizons data.