[HN Gopher] The Atomic Airplane
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       The Atomic Airplane
        
       Author : mpweiher
       Score  : 70 points
       Date   : 2025-05-29 22:16 UTC (4 days ago)
        
 (HTM) web link (whatisnuclear.com)
 (TXT) w3m dump (whatisnuclear.com)
        
       | krunck wrote:
       | Something that should never be built. Along with
       | https://en.wikipedia.org/wiki/Supersonic_Low_Altitude_Missil....
        
         | piombisallow wrote:
         | Radiation effects are vastly overrated.
        
           | gambiting wrote:
           | I agree with you, I've engaged in multiple discussions here
           | on HN with people claiming that a nuclear reactor-equipped
           | rocket or plane makes everything below it poisoned for
           | centuries and uninhabitable just by flying over it. TLDR is
           | that it's simply not true. But, the radiation risks are still
           | significant and cannot be dismissed - and likely mean that
           | we'll never see this kind of propulsion used for anything
           | other than a true "doomsday" weapon where the emissions don't
           | matter but the infinite range and flight time are significant
           | advantages.
        
             | arethuza wrote:
             | For a real "doomsday" weapon you don't even need a delivery
             | mechanism.
             | 
             |  _" When you merely wish to bury bombs, there is no limit
             | to the size"_
             | 
             | For a real life example - Teller's Sundial design.
        
               | Yeul wrote:
               | This reminds me of something I read about the Vulcan
               | strategic bombers:
               | 
               | After dropping their bombs on Russia they were supposed
               | to fly to North Africa and land on airstrips because
               | England was expected to be gone.
        
             | wat10000 wrote:
             | There are huge variations in what's been proposed.
             | 
             | A nuclear-powered airplane would most likely use a closed-
             | cycle reactor with the heat replacing the combustion in
             | otherwise fairly conventional jet engines. They'd be
             | totally harmless in normal operation, with the radiological
             | danger being if they crashed and scattered the contents of
             | their reactor.
             | 
             | Similarly, nuclear thermal rockets like NERVA are closed
             | cycle and pose no radiological danger unless they explode
             | or crash.
             | 
             | And then there are open-cycle designs such as nuclear
             | ramjets, fission-fragment rockets, and Orion. Those are bad
             | news bears for anyone nearby, and possibly the entire
             | planet.
        
               | gambiting wrote:
               | I mean even the "worst" of all designs, the one linked in
               | the comment we're all replying to(SLAM - ramjet design)
               | says this:
               | 
               | " Specifically, he states "The reactor radiations, while
               | intense, do not lead to problems with personnel who
               | happen to be under such a power plant passing overhead at
               | flight speed even for very low altitudes." In both
               | documents, he describes calculations that prove the
               | safety of the reactor and its negligible release of
               | fission products compared to the background. Along the
               | same vein of these calculations, the missile would be
               | moving too quickly to expose any living things to
               | prolonged radiation needed to induce radiation sickness.
               | This is due to the relatively low population of neutrons
               | that would make it to the ground per kilometer, for a
               | vehicle traveling at several hundred meters per second.
               | Any radioactive fuel elements within the reactor itself
               | would be contained and not stripped by the air to reach
               | the ground"
               | 
               | Orion is obviously incredibly bad due to the fact it uses
               | actual nuclear detonations for prepulsion. But it's never
               | been a very serious project, while SLAM has been built
               | and tested.
        
               | wat10000 wrote:
               | Of the things I listed, SLAM seems like the least bad.
               | The reactor at least tries to keep the fission products
               | within the reactor. That said, I would be very skeptical
               | of safety claims from someone who needs it to be safe for
               | their project to be successful, especially from the
               | 1950s.
        
               | cycomanic wrote:
               | It's worth remembering that airplanes have to start, land
               | and taxi as well. So while radiation levels might be safe
               | while the plane is flying at altitude, things might be
               | very different where planes have to land and start.
        
               | lupusreal wrote:
               | I'm convinced that nuclear salt water rockets would be
               | safe to operate in space. And a much better idea than
               | Orion.
        
               | wat10000 wrote:
               | Not frying every satellite above the horizon when used
               | near Earth would certainly be a plus.
        
         | perihelions wrote:
         | The Russians already built one, supposedly [0].
         | 
         | [0] https://en.wikipedia.org/wiki/9M730_Burevestnik
        
           | sandworm101 wrote:
           | Way to bury the lead. The NATO reporting name for this
           | missile appears to be "SKYFALL", maybe the best codename
           | ever.
        
         | acidburnNSA wrote:
         | There's a pretty slick film on nuclear propelled cruise
         | missiles as well: https://youtu.be/8qMuS5kaDBI
        
       | christkv wrote:
       | Definitively up there with most fallout design idea.
        
       | acidburnNSA wrote:
       | If you like nuclear powered flight, you'll also really enjoy this
       | other one that I got digitized in February: "Aircraft Nuclear
       | Propulsion: Manned Aircraft Progress Report" [1]. It's actually
       | from back in the 50s and digitized extremely well.
       | 
       | [1] https://www.youtube.com/watch?v=V-8q8INxQEY
       | 
       | I also have a blog announcement of it if you just want to see
       | some screenshots up front before deciding to dig in: [2]
       | 
       | [2] https://whatisnuclear.com/news/2025-02-03-declassified-
       | nucle...
        
       | webdoodle wrote:
       | The engine to one of these atomic airplanes is on display at
       | Idaho National Labs, near Sun Valley, Idaho.
        
         | acidburnNSA wrote:
         | Two of them actually! Those are HTRE-1/2 and HTRE-3 mentioned
         | in the transcript, (and shown back in the day here [1]). HTRE-1
         | was disassembled and turned into HTRE-2 which is why you only
         | see two of them now.
         | 
         | [1] https://youtu.be/V-8q8INxQEY?t=372
        
       | waffletower wrote:
       | Thunderbirds are go!
        
       | petalmind wrote:
       | Here are some scans from a 1957 Soviet book on nuclear aircraft:
       | 
       | https://xplanes.tumblr.com/post/30938386375/from-the-cover-o...
       | 
       | https://xplanes.tumblr.com/post/30941448265/from-nuclear-pow...
       | 
       | https://xplanes.tumblr.com/post/30944519719/from-nuclear-pow...
       | 
       | https://xplanes.tumblr.com/post/30947450568/from-nuclear-pow...
       | 
       | https://xplanes.tumblr.com/post/30952419021/from-nuclear-pow...
        
       | glimshe wrote:
       | Beyond SpaceX, do we still work on crazy futuristic stuff like
       | this and things such as windowed user interfaces (which was very
       | futuristic at one point)?
        
       | t1234s wrote:
       | I remember seeing an interview with UFO researcher Stanton
       | Freedman and he claimed he worked on nuclear airplane projects.
        
       | loph wrote:
       | This is related.
       | 
       | https://en.wikipedia.org/wiki/Georgia_Nuclear_Aircraft_Labor...
       | 
       | my understanding is that the area is still a bit "hot" with
       | radiation.
        
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       (page generated 2025-06-02 23:01 UTC)