Simulation of Attenuating Airbag Impact Dynamics for Mars Landing

Airbag attenuation technology is suitable for light-weight probes for Mars landing.An attenuating airbag system was designed to fit the critical requirement that peak acceleration should limit to less than 200G during a 30m/s-velocity impact.To study attenuation character economically,the airbag impact dynamics was analyzed with LS-DYNA nonlinear FEA tool.Simulations were made separately by various inflated gas pressures,impact velocities,and impact attitude angles.Simulations depict that with the identical impact velocity,peak acceleration increases with inflated gas pressure,nevertheless,it has little relationship to the Lander's attitude angle.Impact time is only a function of gas pressure and system configuration.System elastic stiffness varies little with impact velocity,which increases with inflated gas pressure but decreases with increasing attitude angle.Conclusion is that a 1.75 m-diameter airbag system is feasible for the design requirement.Ground tests were undertaken as expected.