posted on Apr, 11 2003 @ 06:06 PM
I can't bealive in mach 9. 1mach is 1200kmh depend of air presur and altitude. I don't think that any material can hold tempeture on mach 9. And
what about G-force on pilot. Posted by Serbian Spirit
I hate to break it to you, but mach 9 has been broken long ago. I dont know that the SR 71 is capable of this speed, although it has been known to
exceed mach 6 on a regular basis (although it is "officially" claimed to only be capable of mach 3). Albermarle is correct, the space shuttle
routinely exceeds airspeeds of mach 25+ during reentry, and until Columbia, had a fine time of it.
Although no official information exists publicly about Aurora, the successor to the Blackbird, it is at least rumored to exceed mach 12 in straight
and level flight, powered by Pulse Wave Detonation engines. (This is basically an *external* combustion propulsion system, where the fuel is detonated
outside the aircraft, and the propulsion shockwave is confined and vectored by the mach shockwave which begins to conform to the fuselage of the
aircraft at around mach 6. This form of propulsion is only feasible at extremely high mach numbers)
The original X-15 rocket plane exceeded mach 7 in straight and level flight as far back as the early 50s.
As for the G forces on the pilot, these speeds are attained gradually, not 0-mach 50 in 5 seconds. G Forces are equivalent to flying a standard
aircraft. Keep in mind, going that fast, you have next to no maneuverability, so sharp banking, turning, diving, and any other dogfighting maneuvers
are NOT on the menu. There was a story that during trials with the Blackbird, they made a 90 degree turn at mach 3, and they crossed 3 states before
they completed the turn.
As far as how can they survive the temperature/pressure, well, materials technology is a wonderful thing! We dont have any credible information for
Aurora or other X Craft, but we do know that the Blackbird was almost 100% titanium, with a special high temperature ablative coating. When sitting
cold on the ground, it was actually very loosely fitted (body panels), and the fuel tanks leaked very badly. This was done for a reason, as at high
supersonic speeds, the body panels would thermally expand, sealing itself. The crews, who wore the same spacesuits as the shuttle pilots, ate food in
tubes, same as astronauts. There were stories of them heating thier lunch by holding it against the canopy for about 10 seconds.