CONCEPT

            The ANDE project will use two spherical satellites to determine the Earth’s atmospheric density.  A passive sphere, ANDE I, which would have no payload, would be populated with optical retro-reflectors to be sited by satellite laser ranging facilities.  An active sphere, ANDE II, would similarly be sited by laser ranging sites, but would have Modulating Retro-Reflectors (MRRs) onboard to send down data from an accelerometer and thermal monitoring equipment.  Both satellites are to be similar in size; however, the active satellite should be close to twice the weight of the passive sphere to show how changes in the ballistic coefficient affects drag on the satellite.  Neither satellite has a pointing requirement, but both satellites are required to spin for secondary objective testing.

            As we can achieve the primary objective with any number of passive spheres, more focus has been given to the structure and manufacture of ANDE I than the systems analysis granted to ANDE II.  We collected only cursory information on the equipment to be carried in the active sphere.  Our goal was to provide a structure designed in such a way that it could be used alternatively for the passive or active sphere with minor modification.