Sonic boom measurements from very high altitude and Mach numbers on space shuttle‐orbiter reentry

Abstract

STS‐orbiter reentry sonic boom measurements are presented with particular emphasis on those acquired at very high altitude and Mach numbers. Included, also, are the orbiter physical characteristics and reentry parameters along with a discussion of the nature of its sonic‐boom characteristics as compared to previous experience with aircraft. The applicability of existing sonic‐boom theory, used for aircraft, to the STS‐orbiter is shown. Previous STS reentry boom measurements, along with recently acquired measurements from the STS‐26 and STS‐27 reentry are presented and discussed. The results indicate that there are no significant differences in sonic‐boom signature characteristics from STS‐orbiter and other aircraft. N‐wave type signatures are observed on STS‐orbiter up to Math 23 and altitude of 250 000 ft having an overpressure of about 0.1 psf and a period of about 3.0 s. It is also shown that orbiter reentry maneuvering conditions do not produce focus booms. Although STS‐orbiter signatures are predictable up to Mach 6 and an altitude of 130 000 ft, sonic‐boom theory improvements are required for Mach numbers greater than 6.0. [Work supported by NASA and USAF.]