Long term sustainability is vital to the future space activities. This is a key theme of the discussions in global space forums such as UNCOPUOS. UNISEC in Japan and UNISEC-Global has been facilitating practical space engineering education using nano-satellites. The issues of increasing density of debris in orbit and limited resources of radio frequencies are very relevant to nano-satellite activities at university level. In this paper, firstly UNISEC-Global is introduced, secondly, the concept of space sustainablity is described. Thirdly, UNISEC-Global's contribution to improving awareness of space sustainability among universities across the world is described, and fourthly, innovative technological approaches which may assist in the solution to these problems are introduced, followed by a discussion on the role of UNISEC-Global initiatives in this field.