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Gillis, C. L.

Publications and source records attributed to Gillis, C. L..

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

The Viking decelerator system - An overview.

The Viking mission to place an instrumented lander on Mars in 1976 includes an aerodynamic decelerator as part of the landing sequence. Development of the decelerator, a single-stage mortared disk-gap-band parachute, began in 1965 for the Voyager project and culminated in the flight qualification of the decelerator system for the Viking mission in 1972. This paper summarizes the research, development, and qualification effort. The special operating conditions and the constraints imposed by the Viking mission and the Mars atmosphere, their effects on the decelerator system, and the solution of the resulting technical problems are briefly described.

Gillis, C. L.↗
NASA NTRS1971

Transonic free-flight model testing at large scale

The use of free flight models for transonic testing at high Reynolds numbers is discussed. Several specific examples of experimental investigations are briefly reviewed to illustrate the scope of research that can be conducted by utilizing the advantages of free flight models. These advantages are primarily the lack of interference or constraints imposed by test facilities and model support systems and the dynamic freedom possessed by free flight models. High Reynolds numbers are obtained by using large models flown at relatively low altitudes. It is shown that models 10 meters or more in length will be required for research at Reynolds numbers sufficiently high to provide representative simulation of flow conditions for large modern aircraft. Several methods for launching models of this size are discussed. These methods include free drops from airplanes or balloons and ground launches with the use of internal or external rocket motors. All the launching methods discussed have been successfully demonstrated on flight vehicles of the size and weight required to attain the necessary test conditions.

Gillis, C. L.↗