When astronauts land on Mars, a couple of decades from now, perhaps, they’ll need to find a way to communicate — with each other, with equipment on and around the planet, and with mission control back on Earth. Despite living so far from home, they’ll no doubt want to connect with loved ones, keep their playlists up-to-date or stream the latest episodes of their favorite shows.
But setting up a Wi-Fi connection to Earth’s internet won’t be an option. Earth is simply too far away — around 55 million to 400 million kilometers, depending on where the planets are in their orbits. Spacefarers will need another strategy.