dont forget that the sr-71 was made in several configurations.<br /><br />the a-12 was the interceptor and could carry falcon missiles(early version of phoenix aim-54c) and travel mach 3+<br /><br />the sr-71 also could carry the d-21 drone which had cameras and would travel even faster once it left the sr-71 at mach 3+ over enemy territory at 95,000 ft.<br /><br />so that let us to wonder did they ever have a model that could exceed the 101,000 ft mark? some information is still classified but if you look at it in a conspiracy way then yes the sr-71 could reach that and perhaps higher but not the 300,000 mark needed for low space entry. 21 to 25 miles i can see tops for the sr-71 but no higher.<br /><br />now aurora if it is truely a pulse detonating aircraft might exceed mach 6 and reach an altitude of 200,000 ft but that is just a guess. i have a feeling that technically the scramjet technology is more mature than what they lead to beleive with the x-43 and i feel skunkworks has built an experimental aircraft that can exceed 200,000 ft but isnt a space plane or capable of 300,000+ flight..... YET!!!!!!!!<br /><br />ok maybe its a conspiracy..........<br />