TABLE 3 SSPS STRUCTURAL MODEL WEIGHTS Weight (kgx 106) Weight (Ibx 106) Solar Array 8.12 17.89 Blankets 6.11 13.47 Concentrators 1.02 2.25 Bus/Structure 0.41 0.90 Mast 0.58 1.27 MW ANTENNA 1.98 4.37 ROTARY JOINTS 0.32 0.70 Total Weight 10.42 22.96 MW ANTENNA Inertias (kg-km2) Inertias (slugs~ft2) •yy 134,000 9.87 x 1010 'zz 247,500 18.17x 10‘° initially derived for the first four modes in both the symmetrical and anti-symmetrical models. Comparison of the results showed fairly reasonable agreement between the two methods. Differences in results are attributable to loss of accuracy in the ASTRAL/COMAP approach, due to the relative magnitude of the numbers used in the geometry and member areas. NASTRAN has the capability to handle numbers of much larger magnitude than ASTRAL/COMAP. Also, the reduction in the problem degrees of freedom to accommodate ASTRAL/COMAP adds to its slight inaccuracy. Because of NASTRAN's greater accuracy and faster problem setup time when changing basic input data, this method of analysis was used for the remainder of the study effort. After verifying that initial results obtained from the dynamic model appeared accurate, additional dynamic solutions were obtained. The first 15 symmetrical modes and the first 14 anti-symmetrical modes were derived and the results tabulated in Tables 4 and 5. Input of Elastic Body Characteristics into Attitude Control System Analysis.— Elastic body characteristics derived from the dynamic math model were inputted into the attitude control system analysis in References 29 and 30. The purpose of those studies was to perform the following tasks:
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