Thread

1. scrumper · 1790779923 · focus · HN ↗

   The general tone here seems to be against the effort, but separate the circus from the ringmaster and there is a lot to like here.

   Having a manned, very high altitude, very fast research plane is undoubtedly useful for all sorts of development purposes.

   But more than that, we are as a civilization doing a bad job of preserving cutting edge expertise from the past. We keep letting entire areas of engineering and technology die out without really trying to preserve them even though we know at some point they will come in useful. The skills, processes, even institutional confidence developed in just trying to get an SR-71 flying again will teach us a lot about resurrecting other such dead ends. Aerospace in particular is full of them. That will, for sure, get us out of trouble or speed up something we need at some unknown point in the future. I'd think of it more as developing a general capability than the world's most expensive vintage aircraft hobby.

   1. runjake · 1790780542 · focus · HN ↗

      Look, I'm certified as the world's biggest SR-71 fan. As a kid, I saw it fly a number of times, got to see it up close, and had a family member who worked as an engineer on the program. I believe it may have even been this Blackbird, 844. It impacted me so much that I later went on to work on my own black and other military aircraft.

      I'm assuming that, if this rumor is true, somebody in the Trump campaign forced somebody at NASA to do this out of some misguided nostalgia. My hope is that if they're going to resurrect the Blackbird, they'll at least retrofit modern engines into the thing.

      But there are much more modern, cost-effective ways to build very-high-altitude, very-fast aircraft. I'm doubtful that going manned is the right approach. It takes a lot of weight and space to carry a person and the required life support systems. That capacity could be better utilized for more fuel and sensors.

      There's better technology that's far cheaper to maintain and operate. And you could potentially get hypersonic, or at least near-hypersonic, performance.

      1. ryukoposting · 1790782243 · focus · HN ↗

         > My hope is that if they're going to resurrect the Blackbird, they'll at least retrofit modern engines into the thing.

         Question for people who actually make the engines: is this idea feasible? Like, at all?

         I always imagined a plane's engines to be very tightly coupled to its electrics. In my mind, even if the wire harnesses somehow lined up right, the signals inside would be talking totally different languages.

         1. Tangurena2 · 1790789873 · focus · HN ↗

            The control "computer" for the engines of the SR-71 is hydraulic, not electronic. Some of the parts of this aircraft reach temperatures beyond what current semiconductors can cope with.

            If you watch a YouTube on the J-58 engines that go into this plane, you will find out that it behaves like a jet at "low" speed (like Mach 1 or below) while at Mach 3 it behaves like a ramjet. There's no other aircraft engine that does this.

            1. runjake · 1790794541 · focus · HN ↗

               You might be interested in the GE RTA :-)

               <a href="https:&#x2F;&#x2F;ntrs.nasa.gov&#x2F;citations&#x2F;20050196667" rel="nofollow">https:&#x2F;&#x2F;ntrs.nasa.gov&#x2F;citations&#x2F;20050196667

               The spirit of what you say about the J-58 is true -- it does work like that but it is still &quot;just&quot; an afterburning turbojet.

               I personally think the path forward is a turbine -&gt; ramjet -&gt; scramjet architecture for an aircraft that goes zero to hypersonic.

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