A fundamental problem in spaceflight is spacecraft size. It is very expensive to place satellites into space. As a result, engineers try to design spacecraft to be as small as possible. Space Technology 5 will fly three nanosatellites in a stable major orbit at about 200 by 35,790 km altitude.
Small spacecraft are nothing new.
However, small spacecraft even today are very limited in their capabilities. Typically they lack any propulsion, possess only limited ability for attitude control, and carry one single-function payload. Nanosatellites not only reduce launch costs, but they also reduce the risks associated with flying missions. Currently, several science instruments are flown on a single, large spacecraft. A single instrument or system failure may severely degrade or disable the entire mission.