Abstract: Some spacecrafts have large solar panels and a lot of propellant. These spacecrafts with flexible modes can reach hundreds of order. High-powered computers are needed for these spacecrafts,flexibility dynamics iterative operation within several milliseconds. The measures of decoupling flexibility vibration from body rotation and partial iterative calculation were applied to avoid no convergence of the flexibility dynamics iterative operation because of iterative computing error. The parameters of flexible dynamics model which were decoupled could be calculated off-line. The amount of calculation was decreased for the decoupled flexibility dynamics model as parameters could be computed before simulation. The method doesn't need high-powered computer and is applicable to engineering application. The simulation result validates the decoupling and the iterative operation. The calculation speed can be improved by about two orders of magnitude.

Key words: flexibility dynamics, decoupling, iterative computing, spacecraft