Decoupled Method for Reconstruction of Surface Conditions From Internal Temperatures On Ablative Materials With Uncertain Recession Model
Obtaining measurements of flight environments on ablative heat shields is both critical for spacecraft development and extremely challenging due to the harsh heating environment and surface recession. Thermocouples installed several millimeters below the surface are commonly used to measure the heat shield temperature response, but an ill-posed inverse heat conduction problem must be solved to reconstruct the surface heating environment from these measurements. Ablation can contribute substantially to the measurement response making solutions to the inverse problem strongly dependent on the recession model, which is often poorly characterized. To enable efficient surface reconstruction for recession model sensitivity analysis, a method for decoupling the surface recession evaluation from the inverse heat conduction problem is presented. The decoupled method is shown to provide reconstructions of equivalent accuracy to the traditional coupled method but with substantially reduced computational effort. These methods are applied to reconstruct the environments on the Mars Science Laboratory heat shield using diffusion limit and kinetically limited recession models.
Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI): Complete Flight Data Set
......................................................................................................................................... 1 1.0 Introduction ................................................................................................................. 2 2.0 Hardware Description ................................................................................................ 3 2.1 MEADS Overview ........................................................................................................ 3 2.2 MISP ............................................................................................................................. 5 2.3 SSE ................................................................................................................................ 7 3.0 MEADS PERFORMANCE...................................................................................... 12 3.1 Calibration and System Error Modeling ..................................................................... 12 3.1.1 Calibration Approach .................................................................................................. 12 3.1.2 System Error Modeling ............................................................................................... 13 3.2 Hardware Performance ............................................................................................... 14 3.2.1 MEADS Pressure Sensor Circuit Verification ............................................................ 14 3.2.2 MEADS Thermocouple Circuit Verification .............................................................. 15 3.2.3 MEADS Measurement Data ....................................................................................... 15 3.3 Flight Data Reconstruction ......................................................................................... 16 3.3.1 Reconstruction Methodology ...................................................................................... 16 3.3.2 Trajectory Reconstruction Results .............................................................................. 18 4.0 MEDLI Integrated Sensor Plug (MISP) Performance .......................................... 19 4.1 MISP Hardware Uncertainties .................................................................................... 19 4.2 MISP Thermocouples ................................................................................................. 19 4.2.1 Accuracy in Thermocouple EMF Output ................................................................... 19 4.2.2 Accuracy of Indicated In Situ Temperature ................................................................ 21 4.3 HEAT Sensor .............................................................................................................. 23 4.3.1 Isotherm Temperature: 721  60C ............................................................................ 23 4.3.2 Isotherm Depth............................................................................................................ 24 4.4 Summary of Hardware Uncertainties.......................................................................... 27 4.4.1 MISP Thermocouple Temperature Overall Uncertainty............................................. 27 4.4.2 HEAT Sensor Overall Uncertainty ............................................................................. 27 4.4.3 Arc Jet Testing and Verification ................................................................................. 28 4.5 Hardware Performance ............................................................................................... 28 4.5.1 MISP Thermocouple Circuit Verification .................................................................. 28 4.5.2 MISP HEAT Circuit Verification ............................................................................... 29 4.6 Flight Data .................................................................................................................. 29 4.6.1 Thermocouples ............................................................................................................ 29 4.6.2 HEAT .......................................................................................................................... 30 4.7 Model Validation and Reconstruction ........................................................................ 31 5.0 Conclusions ................................................................................................................ 33 6.0 References .................................................................................................................. 34 7.0 Appendices ................................................................................................................. 38 .................................................................................................................................. 38 Appendix A .................................................................................................................................. 74 Appendix B
Shuttle entry aerothermodynamic flight research - The Orbiter Experiments program
Results of the OEX program are summarized with emphasis on the information on entry aerothermodynamic phenomena derived from Space Shuttle operations. The discussion focuses on OEX experiment complement and operational history, freestream environment and vehicle attitude data, aerodynamic force and moment data, aerodynamic surface data, and vehicle configuration data. Attention is also given to orbiter aerodynamic performance, stability and control, high-altitude atmospheric density variability, direct simulation Monte Carlo validation, orbital drag variation, and computational fluid dynamic technique validation.