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People can definitely survive speeds higher than Mach 5, provided a stable environment—if that weren't the case, only 5 manned space missions would not be fatal (Mercury-Redstone 3, Mercury-Redstone 4, X-15 Flight 90, SpaceShipOne Flight 15P, and SSO Flight 17P). What matters far more is acceleration. A high-intensity roller coaster or mild orbital rocket can reach 3 g's. Typically the limit for endurance for fit humans in ~10-second intervals is 8-10 g's, which not coincidentally is what most military airframes are designed to withstand. However, Colonel Stapp demonstrated in rocket sled tests that at least certain humans can survive upwards of 46.2 g's in very brief intervals.

There have been thoughts of submerging a pilot in a (currently hypothetical) liquid breathing fluid with the same density as the body, allowing the acceleration "normal force" to be cancelled out by buoyancy and converted into a far more tolerable pressure differential. With a flat posture (~10 cm "depth"), a pressure difference of 1 atm at 100 g's would be produced, which is barely tolerable for the average human although breathing is impossible. The greatest pressure difference ever survived by a human was ~21.4 atm by Herbert Nitsch in his record-breaking freedive, meaning the highest acceleration conceivably survivable by anyone using any foreseeable technology is ~2,140 g's. This is higher than can be achieved by any propulsive means besides guns. So, yeah.

If you're talking about surviving speeds of Mach 5 exposed to air, well then that is indeed testable. In that same test, Colonel Stapp reached 635 mph (Mach 0.83) and proved that human skin did not tear when exposed to the dynamic load. However, it's likely that he'd have received (minor) burns if the test went on for longer, as at Mach 1 the frictional and compressive heating of the air is already enough for surface temperature to reach 85 °C (185 °F). Rocket sled tests with chimpanzees in the Mach 2 range revealed extensive 2nd and some 3rd-degree burns which could have proved fatal if untreated—and they did, not because of the burns, but because either the acceleration or dynamic pressure snapped their improperly-placed necks.

However, successful ejections occurred from the SR-71 Blackbird at Mach 3, presumably due to a combination of the protection of the flight suit and the fact that the high-altitude air reduced dynamic and heating loads. This reduced dynamic pressure would result in slower deceleration to a reasonable air speed, leading to longer exposure to less extreme heat, though. You can't win at everything...

Of course, we're not talking about humans, but rather an anthro fox. I'd guess that the maximum survivable acceleration and dynamic pressure would be somewhat lower than that for humans due to a lighter construction, but heat tolerance would be slightly higher—the fur could serve as a minimal "ablative heat shield", and if they share the same integumentary biology as the real species (i.e. few sweat glands in the main coat) burns could be more tolerable.

So, given all information, if Vira ejected at a sufficiently high altitude (say ~50 km at those speeds) wearing her flight suit and managed to use her reflexes to form herself into a position to balance deceleration and heating, I'd give a very marginal "yes" that she could survive, if taken to the burn center immediately after landing. (This is what can happen after a very marginal yes, though...)

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People can definitely survive speeds higher than Mach 5, provided a stable environment—if that weren't the case, only 5 manned space missions would not be fatal (Mercury-Redstone 3, Mercury-Redstone 4, X-15 Flight 90, SpaceShipOne Flight 15P, and SSO Flight 17P). What matters far more is acceleration. A high-intensity roller coaster or mild orbital rocket can reach 3 g's. Typically the limit for endurance for fit humans in ~10-second intervals is 8-10 g's, which not coincidentally is what most military airframes are designed to withstand. However, Colonel Stapp demonstrated in rocket sled tests that at least certain humans can survive upwards of 46.2 g's in very brief intervals.

There have been thoughts of submerging a pilot in a (currently hypothetical) liquid breathing fluid with the same density as the body, allowing the acceleration "normal force" to be cancelled out by buoyancy and converted into a far more tolerable pressure differential. With a flat posture (~10 cm "depth"), a pressure difference of 1 atm at 100 g's would be produced, which is barely tolerable for the average human although breathing is impossible. The greatest pressure difference ever survived by a human was ~21.4 atm by Herbert Nitsch in his record-breaking freedive, meaning the highest acceleration conceivably survivable by anyone using any foreseeable technology is ~2,140 g's. This is higher than can be achieved by any propulsive means besides guns. So, yeah.

If you're talking about surviving speeds of Mach 5 exposed to air, well then that is indeed testable. In that same test, Colonel Stapp reached 635 mph (Mach 0.83) and proved that human skin did not tear when exposed to the dynamic load. However, it's likely that he'd have received (minor) burns if the test went on for longer, as at Mach 1 the frictional and compressive heating of the air is already enough for surface temperature to reach 85 °C (185 °F). Rocket sled tests with chimpanzees in the Mach 2 range revealed extensive 2nd and some 3rd-degree burns which could have proved fatal if untreated—and they did, not because of the burns, but because either the acceleration or dynamic pressure snapped their improperly-placed necks.

However, successful ejections occurred from the SR-71 Blackbird at Mach 3, presumably due to a combination of the protection of the flight suit and the fact that the high-altitude air reduced dynamic and heating loads. This reduced dynamic pressure would result in slower deceleration to a reasonable air speed, leading to longer exposure to less extreme heat, though. You can't win at everything...

Of course, we're not talking about humans, but rather an anthro fox. I'd guess that the maximum survivable acceleration and dynamic pressure would be somewhat lower than that for humans due to a lighter construction, but heat tolerance would be slightly higher—the fur could serve as a minimal "ablative heat shield", and if they share the same integumentary biology as the real species (i.e. few sweat glands in the main coat) burns could be more tolerable.

So, given all information, if Vira ejected at a sufficiently high altitude (say ~50 km at those speeds) wearing her flight suit and managed to use her reflexes to form herself into a position to balance deceleration and heating, I'd give a very marginal "yes" that she could survive, if taken to the burn center immediately after landing. (This is what can happen after a very marginal yes, though...)