The Operationally Responsive Space (ORS) strategy hinges, in part, on realizing technologies which can facilitate the rapid deployment of satellites. Presently, preflight qualification testing and vehicle integration processes are time consumptive and pose as two significant hurdles which must be. overcome to effectively enhance US space asset deployment responsiveness. There is a growing demand for innovative embedded Structural Health Monitoring (SHM) technologies which can be seamlessly incorporated onto payload hardware and function in parallel with satellite construction to mitigate lengthy preflight checkout procedures. In this effort our work is focused on the development of a joint connectivity monitoring algorithm which can detect, locate, and assess preload in bolted joint assemblies. Our technology leverages inexpensive, lightweight, flexible thin-film macro-fiber composite (MFC) sensor/actuators with a novel online, data-driven signal processing algorithm. This algorithm inherently relies upon Chaotic Guided Ultrasonic Waves (CGUW) and a novel cross-prediction error classification technique. The efficacy of the monitoring algorithm is evaluated through a series of numerical simulations and experimentally in two test configurations. We conclude with a discussion surrounding further development of this approach into a commercial product as a real-time flight readiness indicator.

We study the dynamics of a class of flexible dual-spin satellites in which the rotor is spun up by a small constant torque T applied by the platform. We use a previously published zero torque solution that was obtained using the Krylov-Bogoliubov-Mitropolski averaging method. A second application of averaging developed herein leads to a reduction of the equations of motion from a sixth-order system to a single first-order equation describing the slow evolution of energy as a function of the axial angular momentum of the rotor. The geometrical interpretation of this reduction involves projecting solutions onto a certain bifurcation diagram. Numerical solutions of the averaged equation agree with numerical solutions to the full sixth-order system and show that the flexible spacecraft behaves essentially the same as its rigid counterpart during the spinup maneuver.