They'll be launching tons of these satelites, their end goal is a quantum network like the one Germans have been working on, but in space.
The first universal quantum network | ExtremeTech
"Has it been done before?
Not from space, making this launch experimental. But fibre-optic quantum key distribution networks already exist in Europe, the US and China.
The signals weaken over distance though, which this project is hoping to minimise by sending the signals mostly through space, keeping attenuation to a minimum despite the distances involved."
China launches quantum-enabled satellite Micius - BBC News