Attached inflatable ballute for spacecraft deceleration

An innovative, lightweight method, using an inflatable ballute, to increase aerobraking drag and potentially reduce the size of spacecraft (S/C) payloads, is presented. Computational fluid dynamics (CFD) calculations (using the entry environment and trajectory for a Mars 03 entry vehicle) were performed for a generic torroidal-shaped ballute, attached to a baseline S/C configuration. Results from the CFD analysis indicate a maximum heating intensity of 35 W/cm/sup 2/ occurred at the aeroshell-ballute joint interface. A thermal model was developed, incoporating the CFD results, which was used to design a tailored thermal protection system (TPS). The TPS consisted of a multilayered configuration for the higher heat flux area and a fewer-layer configuration for areas with lower heat flux. The total mass of the tailored TPS for the entire ballute surface was about 43% lighter than a more traditional monolithic heat shield design. Lockheed Martin, along with L'Garde, Inc., designed and fabricated a subscale model of an inflatable ballute attached to a rigid aeroshell, to demonstrate ballute bladder stowage and inflation mechanics.