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Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2The following topics related to the dynamics of the 4-mass tethered system are addressed: (1) the development of damping algorithms for damping the out-of-plane libration of the system and the interaction of the out-of-plane control with the other degrees of freedom; and (2) the development of environmental models to be added to the dynamics simulation computer code. The environmental models are specifically a new drag routine based on the Jacchia's 1977 model, a J(2) model and an accurate thermal model of the wire. Regarding topic (1) a survey of various out-of-plane libration control laws was carried out. Consequently a yo-yo control law with amplitude of the tether length variation proportional to the amplitude of the out-of-game libration has been selected. This control law provides good damping when applied to a (theoretical) two-dimensional system. In the actual 3-dimensional 4-mass tethered system, however, energy is transferred to the least damped degrees of freedom (the out-of-plane lateral deflections are still undamped in the present simulations) in such a way as to decrease the effectiveness of the algorithm for out-of-plane libration control. The addition of damping algorithms for the out-of-plane lateral deflections is therefore necessary.
Document ID
19870002382
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Lorenzini, E. C. (Smithsonian Astrophysical Observatory Cambridge, MA, United States)
Arnold, D. A. (Smithsonian Astrophysical Observatory Cambridge, MA, United States)
Cosmo, M. (Smithsonian Astrophysical Observatory Cambridge, MA, United States)
Grossi, M. D. (Smithsonian Astrophysical Observatory Cambridge, MA, United States)
Date Acquired
September 5, 2013
Publication Date
October 1, 1986
Subject Category
Astrodynamics
Report/Patent Number
NASA-CR-178953
NAS 1.26:178953
QR-6
Accession Number
87N11815
Funding Number(s)
CONTRACT_GRANT: NAS8-36606
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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