Summary
Recently, with the escalating cost of large satellite missions, attention has turned to smaller satellites. Their advantages of low overall cost in construction and launch, and short time span between conception and launch has given a new impetus to the further study of the geosphere. By using a combination of space-based and ground-based receivers, it is possible to undertake new and exciting experiments directed towards furthering our knowledge of the ionosphere. Combinations of high Earth orbit satellites, such as the Global Positioning System (GPS), and Low Earth Orbit (LEO) microsatellites are providing the capability for satellite-to-satellite occultation experiments to reconstruct the vertical profile of the ionosphere. The topside ionospheric and plasmaspheric ionisation content may also be explored with satellite-to-satellite experiments. This paper describes some of the experiments proposed for future microsatellites, such as those planned for the Australian satellite FedSat.