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. jandrese · 1790791496 · focus · HN ↗

         > 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.

         Is there? High speed turbofans are still exotic technologies. Or are we doing the research with drone rockets now? I have to imagine that building a modern SR-71 replacement would be an expensive development project with little commercial prospects. The sort of thing that is extremely hard to complete in the modern political environment.

         1. runjake · 1790791726 · focus · HN ↗

            Turbofans are not exotic technologies. They are well understood, and their limitations are well understood.

            Presumably, an SR-71 successor would use a mix of turbofans and ramjet/scramjet to meet their performance (speed/altitude) goals, depending on whether it would be self-sufficient or use takeoff assist from another aircraft.

            1. AshleyGrant · 1790792972 · focus · HN ↗

               Despite them being complex, high-bypass turbofan engines ARE exotic technology. There are vanishingly few countries/companies that have the expertise necessary to produce the single crystal fan blades used in the engines of these aircraft.

               As far as the SR-71, its engines were turbojets that transitioned to ramjets above Mach 2ish. They required a special grade of jet fuel and a dedicated fleet of refueling aircraft.

               I rather doubt an SR-71 successor would use a turbofan. The mission profile really doesn't require it. I would expect it to be a turbojet that transitions (as you said) to a ramjet and eventually a scramjet.

               I would love to see the SR-71 fly again, if only from a nostalgia standpoint, but I really doubt this effort will be successful. I doubt even more that much of value can be accomplished by getting one to be flyable again that couldn't be achieved in a much more cost-effective manner via unmanned aircraft.

               1. AshleyGrant · 1790800352 · focus · HN ↗

                  Edit to my comment, I meant "Despite them being common," not "Despite them being complex."

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