For a species to develop in nature basically two things are needed: an enabling technology and a "niche". In spacecraft design the story is the same. Both a suitable technology and a niche application need to be there before a new generation of spacecraft can be developed. In the last century two technologies have emerged which had and still have a huge impact on the development of technical systems: Micro-Electronics (ME) and Micro-Systems Technology (MST). Many different terrestrial systems have changed dramatically since the introduction of ME and MST and many new systems have emerged. In the same period many nano-satellites have been built and launched and shown that they can perform in space. Still it is not clear what the specific role of these small satellites will be. Where will they go? What will they do? In this paper the authors will try to answer these questions and will refer to the OLFAR space born radio telescope as one of the niche applications for a nano-satellite swarm.