Applications of quantum communication protocols in real world scenarios toward space

Quantum cryptography and quantum computation are based on the communication of single quantum states and quantum entanglement, respectively. Particularly in view of these high potential applications the question arises, whether quantum correlations can be sufficiently well communicated over global distances to be used in communication protocols as predicted by quantum mechanics. Various experiments and possible application of quantum communications on ground and in space are discussed in this article. Thereby, it confirms the feasibility of quantum communication in space on a global scale, involving the International Space Station (ISS) or satellites linking to optical ground stations.