To better simulate reality and give reasons for building space station there should be specific experiment that can be done. The must be sent up inside of another vessel much like the Progress, Dragon, and Cygnus. They would probably need to be crewed to simulate the requirement for pressurized delivery systems. A vessel with full crew could hold 2 experiment, which can only be used once, or 3 additional experiments for every empty crew slot. The results could be sent back with the same limit on vessel capacity or transmitted for 10%. There would also need to be different experiments so there isn't just one that quickly becomes researched.
