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Oddly, I think it's a side effect of the way that technology works. When we humans want to do something we find a way and usually it is extreme and capital inte

Oddly, I think it's a side effect of the way that technology works. When we humans want to do something we find a way and usually it is extreme and capital intensive. Afterward, we find more economical and less extreme ways of doing it. The Colosseum in Rome still exists because the only way to do it was to do it in stone and stone lasts forever. Since then we've built millions of arenas that won't last as long because we've used economic forces to develop just-good-enough structure. Likewise, the SR-71 has been replaced by the just-good-enough surveillance satellite. There's another aspect too. Sometimes we do things just to see that we can. Going to the moon is in that category. If there was a compelling reason to go back we would've. The Concorde, one could argue, was in the same category - we had to have the thrill of taking commercial flight into the supersonic realm, but we found that they economics were such that the thrill of going supersonic and getting there a few hours earlier were not enough to support a market.

dragonwriter 13y ago
> The SR-71 has been replaced by the just-good-enough surveillance satellite. Given that the primary motivation for the SR-71 (and, before it, the A-12) was to have a platform wasn't vulnerable to interception like the U-2, I think satellites aren't merely "just good enough", they are far better in that key respect. They might be worse at "be where we want on demand", but if that's the overriding concern, there's all kinds of other platforms (drones, U-2). The problem with the SR-71 is that it is highly optimized for survivability through speed, but the speed it has doesn't do enough for survivability to be worth the cost given the other alternatives available. > There's another aspect too. Sometimes we do things just to see that we can. Going to the moon is in the category. Well, if you ignore the Cold War geopolitical context of the space race, sure, going to the moon was "just to see that we can".
jordanb 13y ago
The SR-71 was a hack, where the goal was to use 1960s technology to make an areal camera platform that could photograph targets protected by SAMs. The original design brief was that it should be a stealth U2, but as the A-12/SR-71 project developed it became clear that that wasn't possible with the technology of the time, but that they could make a platform that flew so fast the SAMs wouldn't have time to lock, launch, and intercept. There were suborbital spy satellites available before the A-12 even flew: http://en.wikipedia.org/wiki/Corona_%28satellite%29 http://en.wikipedia.org/wiki/Corona_%28satellite%29 The problem was that the cost of the keyhole program was incredible, you needed a whole launch platform plus a whole recovery mission every time you wanted to take a picture. So the SR-71 was a cost-saving measure versus Keyhole. Currently the us military can get the information that the SR-71 could provide more easily and with less danger and cost.
- michaelfeathers 13y ago
  Saw this about a planned successor called the SR-72. I wonder whether it is a serious project? http://theaviationist.com/2013/11/01/sr-72-unveiled/ http://theaviationist.com/2013/11/01/sr-72-unveiled/
dredmorbius 13y ago
The Colosseum in Rome still exist The Colosseum (and much Roman construction) was built with stone but also concrete. The composition of Roman concrete is such that it's much more durable than most modern concrete, due in part to material properties not well understood until recently. There's also a survivor bias built into structures which have survived the test of time: by definition, what's lasted are the structures which have lasted.

dragonwriter 13y ago

> The SR-71 has been replaced by the just-good-enough surveillance satellite. Given that the primary motivation for the SR-71 (and, before it, the A-12) was to have a platform wasn't vulnerable to interception like the U-2, I think satellites aren't merely "just good enough", they are far better in that key respect. They might be worse at "be where we want on demand", but if that's the overriding concern, there's all kinds of other platforms (drones, U-2). The problem with the SR-71 is that it is highly optimized for survivability through speed, but the speed it has doesn't do enough for survivability to be worth the cost given the other alternatives available. > There's another aspect too. Sometimes we do things just to see that we can. Going to the moon is in the category. Well, if you ignore the Cold War geopolitical context of the space race, sure, going to the moon was "just to see that we can".

jordanb 13y ago

The SR-71 was a hack, where the goal was to use 1960s technology to make an areal camera platform that could photograph targets protected by SAMs. The original design brief was that it should be a stealth U2, but as the A-12/SR-71 project developed it became clear that that wasn't possible with the technology of the time, but that they could make a platform that flew so fast the SAMs wouldn't have time to lock, launch, and intercept. There were suborbital spy satellites available before the A-12 even flew: http://en.wikipedia.org/wiki/Corona_%28satellite%29 http://en.wikipedia.org/wiki/Corona_%28satellite%29 The problem was that the cost of the keyhole program was incredible, you needed a whole launch platform plus a whole recovery mission every time you wanted to take a picture. So the SR-71 was a cost-saving measure versus Keyhole. Currently the us military can get the information that the SR-71 could provide more easily and with less danger and cost.

michaelfeathers 13y ago
Saw this about a planned successor called the SR-72. I wonder whether it is a serious project? http://theaviationist.com/2013/11/01/sr-72-unveiled/ http://theaviationist.com/2013/11/01/sr-72-unveiled/

dredmorbius 13y ago

The Colosseum in Rome still exist The Colosseum (and much Roman construction) was built with stone but also concrete. The composition of Roman concrete is such that it's much more durable than most modern concrete, due in part to material properties not well understood until recently. There's also a survivor bias built into structures which have survived the test of time: by definition, what's lasted are the structures which have lasted.