Investigation on Effects of Circumferential Constraint of Membrane on Dynamics of Spinning Solar Sail
- Paper number
IAC-05-C2.2.06
- Author
Mr. Munetaka Kashiwa, University of Tokyo, Japan
- Year
2005
- Abstract
Recently, a solar sail has attracted interest as a new propulsion system for future deep space missions. Various types of solar sail have been proposed and studied. ISAS/JAXA has been planning solar sail missions using a spinning type. The spinning solar sail maintains the deployed shape of a reflector membrane by utilizing centrifugal force without having any support structures. It can reduce its total weight much than solar sails using support structures by reducing weights of support structures. Thus the spinning solar sail has a big advantage over solar sails using support structures since it can obtain much larger acceleration against a given magnitude of solar pressure. However the spinning solar sail has some challenging aspects such as the deployment of the membrane from the packaged and so on. In this paper the effects of circumferential constraints of the membrane on the dynamics of spinning solar sail is discussed. Here what “circumferential constraint” means is described below. When the membrane of the spinning solar sail is fully deployed, a circumferential length of the membrane should be beginmathpiendmath times the diameter, which is referred to as nominal circumference. If the circumferential length is shorter than the nominal circumference, circumference tension is dominant and radial tension is very small. At this time, the short circumferential length constrains the dynamic behavior of the membrane. Therefore we called the shorter circumference than nominal one “circumferential constraint” in this paper. This circumferential constraint is formed by manufacturing error or thermal shrinkage of the membrane. Especially manufacturing error is unavoidable because many small pieces of membrane should be glued or tethered to manufacture a large sail membrane. In this study we analyze the membrane dynamics with the lumped mass model, in which the membrane is modeled as many lumped masses linked by springs and dashpots. By using this model, we show that the presence of small circumferential constraint drastically changes the dynamic equilibrium state and the internal stress distribution of the spinning solar sail in the deployment state. Moreover we reveal that the circumferential constraint of the membrane degrades the performance of reorientation maneuvers of the spinning solar sail.
- Abstract document
- Manuscript document
IAC-05-C2.2.06.pdf (🔒 authorized access only).
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