Based on the new research, some of the scientists involved think that we could see the beginnings of a quantum satellite communication network in as soon as five years.There's already one quantum-equipped satellite in orbit around Earth. Last August, China launched Micius, the world's first quantum satellite. It's intended to be proof of concept for China's global quantum satellite communications network, which it hopes to have up and running by 2030. But first, proponents had to prove that transmitting quantum states from orbit was practical.
Entanglement is kind of like having a single particle existing in multiple locations at once
As detailed today in a paper in Optica, these researchers were able to successfully measure quantum states relayed to a ground station via laser from a satellite 23,600 miles above Earth. Unlike Micius, this satellite was just a run-of-the-mill communications satellite that was part of Europe's SpaceDataHighway and hadn't been optimized for sending quantum states via laser."We were quite surprised by how well the quantum states survived traveling through the atmospheric turbulence to a ground station," Christoph Marquardt, an optical physicist at the Max Planck Institute for the Science of Light, said in a statement. "From our measurements, we could deduce that the light traveling down to Earth is very well suited to be operated as a quantum key distribution network."Over the course of 2015 and early 2016, Marquardt and his colleagues ran experiments from the Teide Observatory in Spain. Since the laser communications technology on the satellite was very similar to the laser technology developed by the Max Planck Institute to enable quantum key distribution, the researchers were able to use the satellite to create quantum states which were then transmitted to the ground and measured for accuracy.Although transmitting a quantum state from space to Earth is not the same as transmitting entangled particle pairs, like the Chinese experiment, the researchers hope that this initial experiment can be built upon in order to turn existing communication satellites into the backbone of a future quantum communication network, which would allow for their rollout much more quickly than starting over from scratch."The paper demonstrates that technology on satellites can be used to achieve quantum-limited measurements, thus making a satellite quantum communication network possible," Marquardt said. "This greatly cuts down on the development time, meaning it could be possible to have such a system as soon as five years from now."Get six of our favorite Motherboard stories every day by signing up for our newsletter.