Using adaptive structures to enable future missions by relaxing ground test requirements

Abstract

Future NASA missions will require large space structures that must maintain accurate surface tolerances for up to 20 years; most flight programs require a ground test verification of the hardware. Because of the influence of gravity, the current state-of-the-art ground test technology cannot accurately determine whether the hardware complies wtih the requirements. The incorporation of adaptive structures into the spacecraft will enable a relaxation of the ground test requirements necessary to validate the hardware for flight. This paper describes the challenges in testing large precision structures, adaptive structures, the data establishing the current state of the art in ground testing, and the utilization of adaptive structures to alleviate the ground test requirements.

Nonlinear motions of beam-mass structure

“…During the experiment, the excitation frequency was held constant The good agreement between theory and experiment indicates that the response of the structure can be modeled as shown here. Other structures like the large space structures envisaged in references [18] and [19] may exhibit similar dynamic behavior when subjected to low excitation levels. Following the approach illustrated in the present study, one could formulate an analytical model to predict the dynamic behavior of these structures.…”

Calibración de acelerómetros para la medida de microaceleraciones en aplicaciones espaciales

“…Los problemas técnicos asociados son el apuntamiento de equipos y la transmisión de vibraciones, con importantes consecuencias, por ejemplo, para la Estación Espacial Internacional, en cuanto a niveles máximos de gravedad residual y g-jitter. También se ha propuesto el concepto de estructura adaptativa, que incluye control activo, con el objeto de generalizar y simplificar la técnicas de análisis y ensayo en tierra de las grandes estructuras (Wada et al, 1991).…”