4 ms·

Reactionless? Presumably the reaction mass would be... air.

• clon 9y ago
  Oh my.. Never thought of that. Surely it does not use the atmosphere as the primary circuit coolant?
  • TheOtherHobbes 9y ago
    https://en.wikipedia.org/wiki/Project_Pluto https://en.wikipedia.org/wiki/Project_Pluto
    • behindmyscreen 9y ago
      If only there were a good way of heating the air without contaminating it with radioactive emissions. If we could figure that out, such an engine would be useful in many non war related jobs.
  • wcarss 9y ago
    That's one of the ways these could run, yes. But hopefully not the way this one is -- there are direct exchange and indirect heating methods that have been researched. Check out Project Pluto on Wikipedia [1], and the Direct Air Cycle part of the Aircraft Nuclear Propulsion page [2]. From the Pluto page, "The principle behind the nuclear ramjet was relatively simple: motion of the vehicle pushed air in through the front of the vehicle (ram effect), a nuclear reactor heated the air, and then the hot air expanded at high speed out through a nozzle at the back, providing thrust." 1 - https://en.m.wikipedia.org/wiki/Project_Pluto https://en.m.wikipedia.org/wiki/Project_Pluto 2 - https://en.m.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion#Direct_Air_Cycle https://en.m.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion#... while we're at it, have a fun tangential short story by Charlie Stross about rockets, missiles, volatile oxidizers, and more, with only a touch of plausible-sounding scifi nonsense: https://www.tor.com/2012/07/20/a-tall-tail/ https://www.tor.com/2012/07/20/a-tall-tail/