State of the art, lightweight scientific experiments available for small to micro satellite missions

A selection of light weight scientific instruments originally designed for major international missions but which, because of their modest resource requirements, can now in addition be flown aboard ‘small’ to ‘micro’ satellites are, briefly, described. These instruments have the capability to either make measurements of constituents of the Earth's energetic particle environment, or provide detailed monitoring of multiple parameters of the cold terrestrial ionospheric plasma. Scientific reasons for flying such instruments in LEO are, in each case, advanced. Individually, they constitute representative examples of a mature genre of commercially available (a cost parameter of £100k/kg can be achieved), light weight, space qualified, instruments which can contribute significantly to the implementation of first class scientific programs aboard small/micro satellites. Uniquely fault tolerant data processing units are a feature of these devices.