China launches world's first quantum science satellite
China has launched the world's first satellite dedicated to testing the fundamentals of quantum communication in space. The $100m Quantum Experiments at Space Scale (QUESS) mission was launched today from the Jiuquan Satellite Launch Center in northern China at 01:40 local time. For the next two years, the craft – also named "Micius" after the ancient Chinese philosopher – will demonstrate the feasibility of quantum communication between Earth and space, and test quantum entanglement over unprecedented distances.
Work on QUESS – a collaborative endeavour between the Chinese Academy of Sciences and the Austrian Academy of Sciences – began in 2011 and the assembly was completed earlier this year. The 600 kg satellite will now be put into Earth orbit around 500 km above ground. The craft's main instrument is a "Sagnac" interferometer that is used to generate two entangled infrared photons by shining an ultraviolet laser on a non-linear optical crystal.
