Dynamic Analysis of the Lightweight Mission Specialist Seats for the Space Shuttle Orbiter

Abstract

The Orbiter Lightweight Seat - Mission Specialist (LWS-MS) is designed to replace the existing mission specialist seats in the space shuttle orbiter. The goal of the LWS-MS project is to reduce the weight of each seat by 50%, while increasing crashworthiness. The development of typical aircraft seats relies heavily on dynamic crash testing. The LWS-MS team at the NASA Johnson Space Center (JSC) reduced the amount of dynamic testing required by performing dynamic analysis of the seat and occupant. The analysis uses the Dynamic Analysis and Design Software (DADS) package by Computer Aided Design Software, Inc. Custom code was added to model the seat restraint system, and to model contact between the occupant and the seat. The occupant is modeled as a group of rigid bodies. The seat is represented by its mass and stiffness matrices and by its normal modes. The DADS model shows good correlation with test data for both low and high level input tests.