A document presents computational simulation studies of a concept for stabilizing the attitude of a spacecraft during deployment of such structures as a solar sail or other structures supported by inflatable booms. Specifically, the solar sail considered in this paper is a square sail with inflatable booms and attitude control vanes at the corners. The sail inflates from its stowed configuration into a square sail with four segments and four vanes at the tips. Basically, the concept is one of controlling the rates of inflation of the booms to utilize in mass distribution properties to effect changes in the system's angular momentum.
More specifically, what was studied were the effects of staggering inflation of each boom by holding it at constant length for specified intervals between intervals of increasing length until full length is reached. The studies included sensitivity analyses of effects of variations in mass properties, boom lengths, rates of increase in boom length, initial rates of rotation of the spacecraft, and several asymmetries that could arise during deployment.
The studies led to the conclusion that the final attitude of the spacecraft could be modified by varying the parameters of staggered inflation. Computational studies also showed that by feeding back attitude and attitude-rate measurements so that corrective action is taken during the deployment, the final attitude can be maintained very closely to the initial attitude, thus mitigating the attitude changes incurred during deployment and caused by modeling errors. Moreover, it was found that by optimizing the ratio between the holding and length-increasing intervals in deployment of a boom, one could cause deployment to track a desired deployment profile to place the entire spacecraft in a desired attitude at the end of deployment.
This work was done by Marco Quadrelli and John West of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Mechanics category. NPO-42176
This Brief includes a Technical Support Package (TSP).
Staggering Inflation To Stabilize Attitude of a Solar Sail
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Overview
The document pertains to a NASA Technical Support Package (NPO-42176) that outlines a method for improving the attitude stability of inflatable structures, specifically focusing on solar sails. The innovation described involves a technique known as "staggered boom inflation," which aims to enhance the deployment and operational stability of these structures in space.
Solar sails are a form of spacecraft propulsion that utilizes sunlight for movement, relying on large, reflective surfaces to capture solar radiation. However, maintaining the correct orientation (or attitude) of these sails during deployment and operation is crucial for their effectiveness. The method proposed in this document addresses the challenges associated with achieving and maintaining this stability.
The staggering inflation technique involves a sequential inflation process of the booms that support the solar sail. By inflating the booms in a staggered manner rather than simultaneously, the method aims to reduce the risk of instability that can occur during deployment. This approach allows for better control over the sail's orientation and minimizes the potential for unwanted oscillations or disturbances that could compromise the mission.
The document also references a broader context for this innovation, linking it to advancements in space flight mechanics as discussed in the proceedings of the AAS/AIAA Space Flight Mechanics Meeting held in January 2006. This connection underscores the relevance of the research to ongoing developments in aerospace technology.
Additionally, the Technical Support Package serves as a resource for those interested in the commercial applications of this technology, highlighting NASA's commitment to sharing aerospace-related developments that may have wider technological, scientific, or commercial implications. It provides contact information for further inquiries, emphasizing the role of the Innovative Technology Assets Management at JPL in facilitating access to this information.
Overall, the document encapsulates a significant advancement in the field of space technology, particularly in the deployment of inflatable structures like solar sails, which could enhance the efficiency and effectiveness of future space missions. The staggering inflation method represents a promising innovation that could lead to improved stability and performance in various aerospace applications.
