Effects of Nosetip Shape Change on Re-entry Vehicle Dispersion

The title problem was investigated using an analytic six-degrees-of-freedom trajectory simulation technique. Input for this simulation includes a nosetip shape-aerodynamic simularity expression and a nosetip shape-normal force correlation, obtained from results of a two-degree-of-freedom trajectory simulation and a three-dimensional inviscid finite-difference calculation based on the meteorological characteristics of the configuration in question. Excellent agreement has been obtained between the simulated parameters and those obtained from flight test data. The analysis shows that nosetip shape changes significantly affect the flight performance of reentry vehicles and can lead to large impact coordinate variations due to both lift and drag. Ablative nosetip drag effects may either increase or decrease the value of the blast wave statement at various points over the reentry trajectory.