This thesis describes those preparatory experiments, that are essiential for the realization of two planned quantum free-space projects. The Quantum Experiments at Space Scale (QUESS) project pursues the aim to enable an unconditional secure quantum key exchange between a satellite and different optical ground stations. Therefore, a satellite mock-up system has been developed, that is used to test the receiving modules of the ground stations located in Tenerife and Graz. Within the second experiment described, a cosmic Bell test is planned to be carried out in order to close the "freedom-of-choice" loophole. The realization and preparation of the used polarization analyzation modules are treated in detail. Additionally, different sources of random numbers are analyzed on their influence on the violation of the Bell inequality.