SEPARATION DYNAMICS OF HEAT SHIELD FAIRINGS

The dynamics associated with the jettisoning of heat shield fairings f rom the parent launch vehicle is investigated. The analysis considers a zip-cord based mechanism employed to jettison the fairings from the accelerating on-going stage. A scheme for characterization of the zip- cord system is described, The geometry of collision is analysed for a known, precomputed structural response. The no-collision domain is con structed in flexibility parameter space for an arbitrarily assumed imp ulse level. Alternatively, the minimum impulse required for a collisio n-free separation is also computed as a function of design parameters. Finally, the analysis enables generation of the upper limits on paylo ad size as well as that of the external mountings for a clean separati on. This methodology has led to the successful separation of shield he at fairings for the two developmental flights of the Indian launcher P olar Satellite Launch Vehicle (PSLV).