The results of tests conducted in a Hotshot-type wind tunnel with air at stagnation temperatures of approximately 2500* K and 9000* K and with helium at stagnation ion ion temperatures varying from 1600* K to 4000* K. For these tests the mach numbers in the test section varied from 11 to about 60 with free-stream Reynolds numbers ranging from 15,000 down to about 30. All of the test results can be correlated ted ted by a parameter that is proportional to the ratio of the mean free path behind the shock wave to the shock-detachment distance. The measured drag coefficient increases from the continuum value (0.92) to a level in the free-molecule flow regime of approximately 2.0.
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