Postflight Aerothermal Analysis of Stardust Sample Return Capsule

The reentry of the Stardust sample return capsule was captured by several optical instruments through an observation campaign aboard the NASA DC-8 airborne observatory. Flow environments obtained from computational fluid dynamics solutions are loosely coupled with material response modeling to predict the surface temperature and the observed continuum emission of Stardust throughout the reentry. The calculated surface temperatures are compared with the data from several spectral instruments onboard the airborne observatory, including the ECHELLE (echelle-based spectrograph for the crisp and high efficient detection of low light emission) camera and conventional spectrometer in Czerny–Turner configuration. The ECHELLE camera recorded spectral intensity at a period in the trajectory before peak heating. The graybody curves corresponding to the average and area-averaged surface temperatures predicted by the computational fluid dynamics and material response coupled simulation have excellent agreement with the recorded data at altitudes lower than 74 km. At these altitudes, the computational fluid dynamics and material response coupling agrees with the surface temperature to within 50 K. The computational fluid dynamics calculation without the material response modeling overestimates surface temperatures because it does not take into account such things as ablation. The overprediction of the computational fluid dynamics and material response simulated surface temperature early in the trajectory coincides with highemission intensity lines corresponding to thermal paint products. The presence of paint on the heat shield could have contributed to the lower observed surface temperatures and could explain the overprediction by the simulated data, which does not account for the paint. The average surface temperatures resulting from the spectrometer in Czerny– Turner configuration telescope analysis agree to within less than 5% with the average surface temperatures predicted by the material response. This observation period included the point of peak heating. The calculated flux based on the surface temperature agrees well with the observed flux. Surface temperature is one of the critical parameters used in the design of thermal protection systems, because it is an indicator of material performance. The coupled computational fluid dynamics and material response approach employed in the present analysis increases confidence for future missions such as the crew exploration vehicle Orion.

[1]  Richard A. Thompson,et al.  A review of reaction rates and thermodynamic and transport properties for the 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K , 1989 .

[2]  Peter Jenniskens,et al.  Observations of the Stardust Sample Return Capsule Entry with a Slitless Echelle Spectrograph , 2010 .

[3]  Peter Jenniskens,et al.  Near-infrared Spectroscopy of the Stardust Sample Return Capsule Entry: Detection of Carbon , 2010 .

[4]  Peter Jenniskens,et al.  Stardust Hypervelocity Entry Observing Campaign Support , 2009 .

[5]  Matthew G. McHarg,et al.  Observations of the STARDUST Sample Return Capsule Entry Using a High Frame Rate Slit-Less Spectrograph , 2008 .

[6]  Peter Jenniskens.  Observations of the STARDUST Sample Return Capsule Entry with a Slit-Less Echelle Spectrograph , 2008 .

[7]  Kerry A. Trumble,et al.  Spectroscopic Observation of the Stardust Re-Entry in the Near UV with SLIT: Deduction of Surface Temperatures and Plasma Radiation , 2007 .

[8]  Prasun N. Desai,et al.  Stardust Entry Reconstruction , 2008 .

[9]  J. G. Parker.  Rotational and Vibrational Relaxation in Diatomic Gases , 1959 .

[10]  Peter Jenniskens,et al.  Intensified Low-Resolution Optical Spectroscopy of the Stardust Sample Return Capsule Entry , 2010 .

[11]  Graham V. Candler,et al.  The solution of the Navier-Stokes equations using Gauss-Seidel line relaxation , 1989 .

[12]  Paul Wercinski,et al.  Surface Heating from Remote Sensing of the Hypervelocity Entry of the NASA GENESIS Sample Return Capsule , 2006 .

[13]  Paul Wercinski,et al.  Digital Still Snapshots of the Stardust Sample Return Capsule Entry , 2010 .

[14]  Thomas J. Horvath,et al.  A Vision of Quantitative Imaging Technology for Validation of Advanced Flight Technologies , 2011 .

[15]  Frank Milos,et al.  Two-Dimensional Ablation, Thermal Response, and Sizing Program for Pyrolyzing Ablators , 2008 .

[16]  Roger C. Millikan,et al.  Systematics of Vibrational Relaxation , 1963 .

[17]  H. C. Yee,et al.  A class of high resolution explicit and implicit shock-capturing methods , 1989 .

[18]  G. Candler,et al.  Data-Parallel Line Relaxation Method for the Navier -Stokes Equations , 1998 .

[19]  E. P. Bartlett,et al.  An analysis of the coupled chemically reacting boundary layer and charring ablator. Part 4 - A unified approximation for mixture transport properties for multicomponent boundary-layer applications , 1968 .

[20]  C. Park,et al.  Nonequilibrium Hypersonic Aerothermodynamics , 1989 .