Very Large Space Structures Orbital Deployment, Testing and Validation
- Paper number
IAC-08.C2.2.3
- Author
Dr. Richard Helms, Jet Propulsion Laboratory/NASA, United States
- Coauthor
Mr. Robert E. Freeland, National Aeronautics and Space Administration (NASA), United States
- Year
2008
- Abstract
Many early technology concepts for large Earth orbiting space structures sized up to 1000 meters were investigated in the 1960’s and carried through into the late 1970’s. These endeavors were in response to user community interest in employing this technology for a variety of new space applications. The major classes of enabling technologies for these very large systems included self-deploying systems, on-orbit assembly, and on-orbit manufacturing. Interest in using this technology waned when meaningful research showed that concept validation could not be performed adequately on the ground while at the same time it also became apparent that orbital validation experiments would be “astronomically” expensive. As a consequence of these perceptions, only self-deployable concepts in the size range of up to 15 meters were selectively addressed, since only they appeared to lend themselves to significant and affordable ground testing. Subsequent to the NASA sponsored Inflatable Antenna Experiment (IAE), we learned that the only serious interest in that technology was with the U.S. DoD. Additionally, this interest was for structures in the range of hundreds of meters. As a consequence of our experience with the IAE, we were given the opportunity to investigate the feasibility of inflatable space structures technology for specific classes of applications. Several specific deployable structural system concepts such as the Large Radar Antenna (LRA) and the Innovative Space-based Antenna Technology (ISAT), were developed to the point of preliminary designs for structures from 50 to 300 meters. As they matured, it quickly became apparent that these configuration designs presented new challenges with respect to (a) ground demonstrations of functional performance, (b) experimental determination of structural characteristics, and (c) validation of performance predictions from analytical models. These issues were addressed by the DoD development programs, and were recognized as potential “show stoppers”; but a subsequent programmatic termination of the developments precluded any meaningful maturation of approaches for their solutions. However, the illumination of such large structures technology challenges suggested that new and/or alternate approaches were needed to enable this unique class of space structures. Such a review and assessment has, in fact, been recently completed. The study’s primary conclusion identifies an approach based on simple robotic assembly of identical self-deployable modules that have great potential for the classes of very large structures; in particular, for the U.S. DoD (ref. 2). This basic approach has precedence and was identified in 1981 by General Dynamics Corporation for the NASA Langley Research Center. This new look at an “old” approach takes advantage of the early and innovative concepts while incorporating the more recent state-of-the-art technologies for large (self-deployable) space structures, sensors, guidance/control, precision robotic articulation... This proposed IAF 2008 paper addresses the basic definition of this robotic/modular self-deployable approach to the point of (a) illumination of its specific advantages as compared to a single “huge” self-deployable system (risk, cost and schedule), (b) definition of the orbital functions associated with this assembly concept that would require new technology development, and (c) the classes of structures that might benefit from such an assembly procedure. The specific elements of this paper include: (a) characteristic examples of the early concept developments in the 1970’s, (b) the current state of the art for self-deployable structures, (c) the U.S. DoD concept developments, (d) the definition of this alternate orbital assembly approach for the validation of enormous space structures systems, (d) orbital functions requiring new technology, (e) ground test limitations for the characterization of very large structures, and (f) references for essentially all the concepts discussed. 1. Freeland, R. E.; Helms, Richard G.; Willis, Paul B.; Mikulas, M. M.; Stuckey, Wayne; Steckel, Gary; and Watson, Judith, “Inflatable Space Structures Technology Development for Large Radar Antennas”, IAF Paper IAC-04-IAF-I.1.10 presented at the 55th Congress of the International Astronautical Federation, Vancouver, Canada, October 4-8, 2004. 2. Freeland, R. E.; Helms, Richard G.; Mikulas, M. M., “The Applicability of Past Innovative Concepts to the Technology for New Extremely Large Space Antenna/Telescope Structures”, ICES Paper 2006-01-2063 presented at the 2006 SAE International Conference, Norfolk, Virginia, US, July 17, 200
- Abstract document
- Manuscript document
IAC-08.C2.2.3.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.