Aerial Platform Design Options for a Life-Finding Mission at Venus and a Singularity-Free Dynamical Model Using Euler Parameters Applied to a Notional Venus Life Finder Sample Return Vehicle

Weston Buchanan, Purdue University

Abstract

Unexplained signals emanating from the pervasive Venusian clouds have intrigued scientists for more than half a century. Efforts to account for a myriad of perplexing measurements have motivated the development of new atmospheric missions to Venus. Fulfillment of science objectives in the inhospitable Venusian environment necessitates a range of mission architectures, each of which poses significant design challenges which guide the development of new technologies. Missions of greater scope require increasingly intricate sample collection and measurement techniques, leading inevitably to the demand for long-duration science operations within the clouds. Sustained flight in the Venusian atmosphere may be afforded by high-altitude balloons. As such platforms have been studied extensively for terrestrial applications, it is prudent to consider which designs are most suitable for a given set of science goals. We present four balloon design options to accommodate Venus atmospheric science missions. We discuss system masses, envelope volumes, material characteristics, and mechanisms for altitude control as determined by the science objectives and cloud conditions. We consider three variations of a baseline mission architecture and corresponding gondola designs accommodating their distinct science instrument suites. The scientific value of long-duration in situ atmospheric sampling is surpassed only by the return of Venusian cloud material to Earth for investigation in a laboratory setting. Sample capture, orbit acquisition, and subsequent return to Earth may be accommodated by a high-altitude balloon, rocket, and rendezvous vehicle. Precise understanding of the balloon-rocket dynamics inside the clouds is required for launch attitude acquisition and may inform sample capture strategy. We present a generalized dynamical model for a balloon-gondola system. We model the system as a triple-spherical-floating-compound pendulum (TSFCP). Dynamical analyses of pendular motion frequently rely on the use of Eulerian angles as generalized coordinates, inevitably resulting in the residence of trigonometric functions in the denominator. We present nonsingular equations of motion in terms of Euler parameters. We characterize a notional Venus sample return platform and simulate its motion in the Venusian atmosphere. We discuss the behavior of the system in response to wind gusts and initial perturbation. We consider limitations of the model as well as opportunities for its extension into future work.

Degree

Ph.D.

Advisors

Longuski, Purdue University.

Subject Area

Energy|Planetology

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