These satellites are currently being researched and developed to serve as satellite clusters for short periods of time. Their small size (<20 kg) make them relatively inexpensive, and thus are easily dispensable after they have finished serving their purpose. The low mass however introduces unique issues into controlling the objects orientation with its target, and various other satellites in its cluster. The low thrust levels dictated by the application can only be fulfilled through the use of micro-thrusters - throat diameters ~90um. These length scales necessitate unique flow characteristics (Re < 1000) that cause viscous boundary problems that are traditionally not an issue.
