Micro Systems Technology and Micro-Electronics for space applications can draw great advantages from fast prequalification in a real space environment. This is true for technology in general, but probably even more so for these new technologies. Nano-satellites with a mass of 1 to 3 kilograms may provide such a test environment at acceptable cost. In addition they provide an opportunity for close co-operation between industries, institutes and universities, and allow also for active involvement of students in mission, hardware and software design and development during their studies. This paper discusses such an approach and illustrates it by means of a twoyear project, Delfi-C3, of the Faculty Aerospace Engineering (AE) and the Faculty Electrical Engineering, Mathematics and Computer Sciences (EEMCS) of Delft University of Technology in the Netherlands. The project is executed in co-operation with Dutch Space and TNO Science and Industry, which supply two of the payloads flown.