A Literature Review on Quantum Experiments at Space Scale—QUESS Satellite

QUESS/Micius (Quantum Experiments at Space Scale) satellite is a sun-synchronous orbit satellite which is a joint Chinese-Austrian satellite mission operated under Chinese Academy of Sciences (CAS) and with the University of Vienna and the Austrian Academy of Sciences (AAS). It has base stations in Austria and in China at a distance of separation of 7600 km, at a height of 300 km. QUESS is designed to do quantum experiments at space scale, which uses a laser with unknown polarization leading to the quantum states, in space. It is used over long distances for the development of quantum encryption and quantum teleportation technology. It provides a secure communication of data with the least delay of data transmission along with the help of teleportation achieved by quantum entanglement along with usage of the principle of superposition. It works on the principle of Sagnac effect. Any eavesdropping attempt if done, it causes the change in the quantum states of the photons, such that it can be detected with the help of other qubits in the same pair. Quantum key distribution is used to generate a random key for every quantum entangled pair for quantum cryptography of the pair, which can be opened only at the receiver, maintaining a high level of secrecy. These codes are processed by quantum processors in order to open the lock that is placed on them by the random key, with the help of quantum computers at the receiving ends. It is also used to understand the quantum teleportation.