Proposed aerothermodynamic experiments in transition flow using the NASA/ASI tethered satellite system-2

Aerothermodynamic, aerodynamic, and atmospheric science data acquired between 55 and 150 km has been limited by the lack of vehicles or platforms capable of sustained operation at these altitudes. Tethered satellites, which have been under study for this purpose by NASA, the Italian Space Agency (ASI), and others for more than a decade, are expected to become a reality by mid-1991. This approach, in which an instrumented platform is maintained at a desired altitude by a tether attached to a host vehicle orbiting at higher altitudes, will provide the first opportunity to obtain steady state data over an extended period encompassing one or more orbital revolutions. This paper describes the objectives and measurement methods for the first of the facility-class satellites, the TSS-2, which is proposed for a 1995 deployment, and gives the status of the experiment definition. Monte Carlo modeling of the flow fields at 130 km around the baseline 1.6 m diameter sphere is discussed and illustrative results of the modeling given.