China is about to make one giant leap forward in the Space Race. On Tuesday, they will launch the first quantum satellite, which could allow for the total encryption of communications in a way that would make them invulnerable to hackers, a tremendous advance in technology that every government would crave.

This satellite, which will be blasted into space from northwestern China’s Gobi desert, will permit Chinese researchers to transmit test messages between Beijing and northwestern China, in addition to worldwide locations, according to media reports. If the tests prove to be successful, it will be yet another major step toward a hacker-proof communication network.

It also gives China an edge over the Europeans and United States, which have been working toward such technology but hasn’t demonstrated it yet.

Quantum communications work by using subatomic particles to connect two points. A hacker that would try to intercept the message would change the form of the message in a way that would alert the sender and cause the message to be changed or deleted entirely.

The name of the project is Quantum Experiments at Space Scale (QUESS), and it is a joint Austrian-Chinese satellite operated by the Chinese Academy of Sciences and in cooperation with the University of Vienna and the Austrian Academy of Sciences. This proof of concept mission is designed to facilitate quantum optics experiments over very long distances.

QUESS produces pairs of entangled protons, allowing ground stations to establish secure quantum channels even when separated by vast distances. However, it does have limitations: it needs line of sight to operate and can’t operate in sunlight.