Experimental Test of Spacecraft Parachute Deployment using Real-Time Hybrid Substructuring

Spacecraft are subjected to a variety of extreme loads during the course of a mission. One such demanding period during reentry is parachute deployment when a mortar on the spacecraft is used to deploy the parachute. Firing the mortar to expel the parachute imparts an impulsive force on the spacecraft and results in vibration throughout the spacecraft. Successful deployment of the parachute is critical to the success of the mission, and accurate prediction of the impulsive forces exerted on the spacecraft during deployment is paramount to the design and safety of the spacecraft. Typically the time history of the reaction force of the mortar is measured experimentally using a rigid mounting system. This approach neglects the structural compliance of the spacecraft and thus neglects the dynamic interaction between the mortar and spacecraft. This may lead to differences between the force profile observed during laboratory testing and those observed during the mission of the spacecraft.