Charles R. Sandy

Recent Developments in Inflatable Airbag Impact Attenuation Systems for Mars Exploration

At the end of the seven-month cruise stage, the MER vehicles will enter Mars’ atmosphere and begin the entry, descent & landing phase. Initially, aero-braking and deceleration are achieved using a Viking-style heat shield and parachute, followed by the firing of backshell mounted rocket assist descent (RAD) and transverse impulse rocket system (TIRS) motors. Just before impact the airbag system will inflate to cushion the landing. Upon reaching the surface, the spacecraft is expected to bounce more than a dozen times, and could roll as far as one kilometer (0.6 mile). When it stops, the airbags will deflate and retract and the petals will open up, deploying egress aides and revealing the rover.

SIAD-R: A Supersonic Inflatable Aerodynamic Decelerator for Robotic missions to Mars

Nomenclature A_Vehicle = Projected area of the vehicle prior to SIAD-R deployment A_Vehicle+SIAD = Projected area of the vehicle and deployed SIAD-R Cd_Vehicle = Drag coefficient of the vehicle prior to SIAD-R deployment Cd_Vehicle+SIAD = Drag coefficient of the vehicle and deployed SIAD-R ∆(CdA) = Change in the product of drag coefficient and projected area due to SIAD-R deployment LDSD = Low Density Supersonic Decelerator Program MSL = Mars Science Laboratory P = Gauge pressure of the inflation gas inside the SIAD-R Q = Dynamic pressure Q:P = Ratio of the instantaneous dynamic pressure to instantaneous SIAD-R inflation pressure R&R = Retention and release assembly SFDT = Supersonic flight dynamics testing SIAD-R = Supersonic Inflatable Aerodynamic Decelerator for Robotic-class missions

Orion CEV Earth Landing Impact Attenuating Airbags - Design Challenges And Application

Airbags are currently being evaluated by NASA Langley Research Center (LaRC) as a candidate impact attenuation system technology for earth landing of the Orion crew exploration vehicle (CEV). The purpose of the system is to limit landing loads and provide stability, to protect the crew and to allow vehicle reuse. Other candidate technologies include retro-rockets, crushables, and hybrid approaches. In support of LaRCs investigation, ILC Dover has generated a conceptual design of an airbag landing system (ALS) for a generic CEV and fabricated a prototype airbag set. ILC modeled the system using LS DYNA, and showed that the proposed design meets objectives in response to nominal and off nominal landing scenarios. Presented herein is an overview of airbag principles of operation, key requirements, design drivers, configuration trades, supporting analysis, and a design overview. Materials selection is discussed, along with an overview of planned testing.

CEV Airbag Landing System Design

Airbags are currently being evaluated by NASA Langley Research Center (LaRC) as a candidate impact attenuation system technology for earth landing of the Orion Crew Exploration Vehicle (CEV). The purpose of the system is to limit landing loads and provide stability, to protect the crew and to allow vehicle reuse. Other candidate technologies include retro-rockets, crushables, and hybrid approaches. In support of LaRCs investigation, ILC Dover has generated a conceptual design of an Airbag Landing System (ALS) and has fabricated prototype and test article airbag sets. ILC modeled the system using LS DYNA, and showed that the proposed design meets objectives in response to nominal and off nominal landing scenarios. Presented herein is an overview of airbag principles of operation, key requirements, design drivers, configuration trades, supporting analysis, and a design overview. Materials selection is discussed, along with a testing overview.