Guide Rails for Linear Separation of Powered Descent Vehicle from Mars Science Laboratory Backshell

During descent through the Martian atmosphere, Mars science laboratory (MSL) uses three sets of guide rails and rollers to control the separation dynamics of the powered descent vehicle (PDV) from the Backshell and parachute. The guided linear separation of the two bodies over a distance of half a meter mitigates the risk of re- contact which could result in unexpected and detrimental vehicle dynamics. The guide rails are comprised of three thin beams oriented in 120 degree intervals around the circumference of the Backshell's internal structure, and they interface with three sets of four rollers mounted on the exterior of the PDV. This configuration resists motion in 5 DOF. The only unconstrained DOF is in the direction of desired separation. Analysis was used to size the guide rail and rollers, and tests will be performed to validate the design's capability to perform as required during the dynamic separation event.