Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!think!ames!oliveb!sun!concertina!fiddler
From: fiddler%concertina@Sun.COM (Steve Hix)
Newsgroups: sci.space.shuttle
Subject: Re: Shuttle landing
Message-ID: <71965@sun.uucp>
Date: 6 Oct 88 21:38:17 GMT
References: <69@sjs.sj.ate.slb.com>
Sender: news@sun.uucp
Lines: 17

In article <69@sjs.sj.ate.slb.com>, doyle@sjs.sj.ate.slb.com (Matt Doyle, 408-437-5284) writes:
> 
> I haven't seen this question asked yet so I'll stick my neck out..
>   
> why were there two sonic booms when the STS passed over head when landing
> and not one?? I heard the news casters telling people to prepare for the
> double sonic boom, so I assume that it is normal.

This is normal for supersonic aircraft (and spacecraft, too :} ).

There are a number of distinct shockwaves forming from parts of
the airframe, the (by far) largest being from the nose and tail.

Until a supersonic craft is a loong distance from the listener,
you normally hear two closely-spaced booms, the timing being 
somewhat variable, depending on the speed of the craft, its
length, atomospheric conditions, ...