Propulsive Descent Technologies (PDT): Original Content Project

This capability is needed in order to enable future human-precursor and human-scale missions to Mars.</p><p>One possible technology to enable future high mass missions to Mars is the use of retro propulsion during the entry phase.&nbsp; Supersonic retro propulsion involves using thrusters directed in opposition to the oncoming airflow to decelerate the entry vehicle while it is traveling at supersonic speeds.</p><p>The project will seek to partner with a commercial launch provider to obtain flight data.&nbsp; The data acquired by the proposed government-commercial partnership are expected to include the following aerosciences products:</p><ul><li>Vehicle state (position, velocity, attitude, attitude rates, etc.)</li><li>Temperatures, heating rates, and pressures on the vehicle&rsquo;s outer skin</li><li>Imagery provided by NASA and its contractors, in addition to vehicle propulsion system performance data.</li></ul><p>&nbsp;</p><p>Available NASA Computational Fluid Dynamics (CFD) tools will be exercised at a few select conditions during the SRP burn for each flight data set in order to provide insight into how the models compare against the data.&nbsp; The commercial partner&rsquo;s engines will be properly scaled in the CFD calculations using established scaling parameters with varying degrees of exhaust modeling fidelity.&nbsp; Solutions will be completed on custom grids for each CFD code using geometries provided by the commercial partner.</p><p>Objectives (for each code):</p><ol><li>Establish computational requirements (grid, run time, number of CPUs, etc.) and the effects of turbulence modeling and time-accurate simulations on results</li><li>Examine varying levels of engine exhaust modeling (perfect gas vs. simulated gas vs. multi-specie gas)</li><li>Provide best practices for obtaining grid-converged solutions (flow initialization, time step requirements, grid adaptation, etc.)</li><li>Make blind comparisons of the &ldquo;best&rdquo; solutions with the flight data set(s), including flight imagery provided by NASA</li></ol><p>&nbsp;</p><p>The PDT project will also develop vehicle configurations that support landing of a 2 metric ton (t) article on the Mars surface.&nbsp; Project representatives will develop trajectories and supersonic retro propulsion profiles for the vehicle configurations using the CFD models.&nbsp; The project will investigate interactions between vehicle subsystems, structures and thermal protection, the Mars aero environment, mass and center of gravity, and control techniques.&nbsp; &nbsp;</p>