Development of a new-generation active falling sphere

Observations of the winds and temperatures are often required in determining the dynamics of the middle atmosphere. Presently, such measurements are made using rocket-launched involve inflatable falling spheres whose accelerations are observed by ground-based precision radars. The active rigid falling sphere that was developed in the 1970s used precision accelerometers to determine the drag/density-produced accelerations, but these systems required large and expensive launch vehicles. Our group is presently developing a new-generation active falling sphere that combines nanoiechnology accelerometers along with modern GaAs RF transmitters in a 100-150 gram package. This new instrumentation can then be added to the standard inflatable sphere launched by a met rocket or separately deployed from a larger rocket in which it is carried as part of a much larger scientific instrument package. In either case, this instrumented sphere system does not require a high-precision radar track, and thus it is very adaptable for field investigations. A description of our measurement approach and progress in the instrument development is presented.