Actually, if memory serves, Mach 1.0 at mean sea level and mean atmospheric conditions is about 714 MPH at sea level.
However, the speed of sound varies proportionally to the density of the medium, in this case, air. So at higher temperatures, and higher altitudes, the speed of sound increases. At the sort of near-space altitudes at which this thing will probably operate, Mach 5 is close to 5000 MPH.
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Actually, if memory serves, Mach 1.0 at mean sea level and mean atmospheric conditions is about 714 MPH at sea level.
However, the speed of sound varies proportionally to the density of the medium, in this case, air. So at higher temperatures, and higher altitudes, the speed of sound increases. At the sort of near-space altitudes at which this thing will probably operate, Mach 5 is close to 5000 MPH.