93-184
Effects Of Aerodynamic Lift On The Stability Of Tethered Subsatellite System
Mehdi Keshmiri* and Arun K. Misra**
Abstract
Dynamics and stability of a two-body tethered system are investigated considering the aerodynamic lift on the subsatellite in tddition to the aerodyn~mic drag. The Free Molecular Flow Model is users to calculate the aerodynarnic forces on the subsatellite. Equilibrium configurations of the system are obtained numerically. Equations of motion are linearized analytically about the equilibrium configuration through a symbolic manipulation language, Maple V., and stability behaviour of small oscillations about the equilibrium configuration is analyzed. An extensive parametric study is done to understand the effect of aerodynamic forces (lift and drag) on the stability of the uncontrolled system. It is shown that the stability behaviour changes significantly if the subsatellite is changed from a body with no lift to a body with lift. Hence, an unstable system with a spherical subsatellite can be stabilized if aerodynamic surfaces are appropriately added. It is concluded that consideration of the aerodynamic lifting forces in addition to the aeodynamic drag forces on the subsatellite is indispensable for proper designof a tethered subsatellite system deployed in a low-altitude orbit.
*Graduate student, Department of Mechanical Engineering, McGill universitv, 817 Sherbrooke Street West, Montreal, Province of Quebec, Canada H3A 2K6.
**Professor, Department of Mechanical Engineering, McGill university, 817 Sherbrooke Street west, Montreal, Province of Quebec, Canada H3A 2K6.