4 ms·

Sure, but don't we have drones for that now? The high altitude spy planes (U2, SR-71) were mostly to prevent being shot down; surviving to return the film to b

Sure, but don't we have drones for that now? The high altitude spy planes (U2, SR-71) were mostly to prevent being shot down; surviving to return the film to base. Drones don't need to bring film back, and it's not such a big deal if a few of them are lost.

saulrh 9y ago
If it can be shot down, I think that it's probably safe to assume that it won't be able to see anything particularly interesting. I'd expect something like Groom Lake to be surrounded by an impenetrable wall of interceptors and SAM sites. Though I suppose that you could try to make your drones so cheap and in such volume that shooting them down becomes logistically and economically infeasible, but that's another strategy entirely.
- mabbo 9y ago
  > I'd expect something like Groom Lake to be surrounded by an impenetrable wall of interceptors and SAM sites The whole idea of the SR-71 was that it went so fast that SAMs could just barely not catch up to it before they ran out of fuel. Any other plane couldn't outrun them, but the Blackbird? Well, Mach 3.4 will give you some breathing room.
  - astdb 9y ago
    The standard evasion tactic for SR-71 upon launched against was to simply accelerate.
    - deleted 9y ago
      [deleted]
    - Already__Taken 9y ago
      That would be the only option. It's not like you can turn much you'd pass out or snap the airframe. I imagine thought a little snake left/right might compromise getting the images that was the point of the mission.
      - cryptonector 9y ago
        Apparently it could also turn pretty hard. Mind, it's turn radius was huge, but at mach 3.2 it still meant pulling a lot of g's.
  - pdelbarba 9y ago
    More to the point, it takes time to notice, track, lock and (in some cases) get approval to fire. That gives you seconds to minutes to not only fire but for the missile to reach the intercept point. Missiles and radar tend to operate in a "bubble". Even with the Russian S200 system at 190 miles range, the time you spend in that "bubble" when you're at 70k ft is not often long enough to do anything. That also assumes the aircraft directly overflies the battery. You can play games like pointing the camera sideways and observing from an angle if you know there are going to be angry people with guns nearby.
  - burfog 9y ago
    Mach 3.4 was also fast enough that early radar systems couldn't track it. The plane would move far enough between radar pulses that it got filtered out as noise.
  - mikeash 9y ago
    The state of the art advances. There are SAMs today that can shoot down ICBMs. I would guess that one reason the SR-71 was retired, besides the official line that it was expensive and made obsolete by satellites, is that it was no longer invulnerable as it had been when it was new.
IndrekR 9y ago
Just speculating here on two points: - There is no real need for SR-72 to be manned on all flights; - Hypersonic plane would be very good for small (2m wingspan) drone delivery behind the enemy lines fast (in half an hour). This was already a concept with M-21/D-21, but now the drone part can be much smaller and one plane could carry more than 4 of those. Satellites are quite limited when you need to make fast decisions. Hypersonic plane will move about 7 times slower than an optical recce satellite, yet it can maneuver very fast if you need to relocate the imaging area and can get at least 10 times closer to the target. Instruments can be selected/improved even after the first flight of the plane -- not true for the satellites.

saulrh 9y ago

If it can be shot down, I think that it's probably safe to assume that it won't be able to see anything particularly interesting. I'd expect something like Groom Lake to be surrounded by an impenetrable wall of interceptors and SAM sites. Though I suppose that you could try to make your drones so cheap and in such volume that shooting them down becomes logistically and economically infeasible, but that's another strategy entirely.

mabbo 9y ago
> I'd expect something like Groom Lake to be surrounded by an impenetrable wall of interceptors and SAM sites The whole idea of the SR-71 was that it went so fast that SAMs could just barely not catch up to it before they ran out of fuel. Any other plane couldn't outrun them, but the Blackbird? Well, Mach 3.4 will give you some breathing room.
- astdb 9y ago
  The standard evasion tactic for SR-71 upon launched against was to simply accelerate.
  - deleted 9y ago
    [deleted]
  - Already__Taken 9y ago
    That would be the only option. It's not like you can turn much you'd pass out or snap the airframe. I imagine thought a little snake left/right might compromise getting the images that was the point of the mission.
    - cryptonector 9y ago
      Apparently it could also turn pretty hard. Mind, it's turn radius was huge, but at mach 3.2 it still meant pulling a lot of g's.
- pdelbarba 9y ago
  More to the point, it takes time to notice, track, lock and (in some cases) get approval to fire. That gives you seconds to minutes to not only fire but for the missile to reach the intercept point. Missiles and radar tend to operate in a "bubble". Even with the Russian S200 system at 190 miles range, the time you spend in that "bubble" when you're at 70k ft is not often long enough to do anything. That also assumes the aircraft directly overflies the battery. You can play games like pointing the camera sideways and observing from an angle if you know there are going to be angry people with guns nearby.
- burfog 9y ago
  Mach 3.4 was also fast enough that early radar systems couldn't track it. The plane would move far enough between radar pulses that it got filtered out as noise.
- mikeash 9y ago
  The state of the art advances. There are SAMs today that can shoot down ICBMs. I would guess that one reason the SR-71 was retired, besides the official line that it was expensive and made obsolete by satellites, is that it was no longer invulnerable as it had been when it was new.

IndrekR 9y ago

Just speculating here on two points: - There is no real need for SR-72 to be manned on all flights; - Hypersonic plane would be very good for small (2m wingspan) drone delivery behind the enemy lines fast (in half an hour). This was already a concept with M-21/D-21, but now the drone part can be much smaller and one plane could carry more than 4 of those. Satellites are quite limited when you need to make fast decisions. Hypersonic plane will move about 7 times slower than an optical recce satellite, yet it can maneuver very fast if you need to relocate the imaging area and can get at least 10 times closer to the target. Instruments can be selected/improved even after the first flight of the plane -- not true for the satellites.