UniS and SSTL have designed and built many microsatellites. The main design drivers have been electrical functionality and launcher accommodation. this has led to standardisation of the structure, with only minor modifications over the years. As the markets for microsatellites mature more demands are made in terms of power, cost and available payload volume.
Several designs have been developed to meet demands, and they have been proposed for a variety of missions. Specifically the Gander mission has driven a new design which addresses its strict requirements in a very efficient way.