4 ms·

interesting if the Neutron will use electric-pump-fed engines, is this a concept that is scalable to bigger engines?

• Gibbon1 6y ago
  I read a paper that indicated you can build them to any arbitrary size. Electric feed pump designs don't get worse as they get bigger. But turbo pumps have better performance at large sizes than electric feed pumps. However the paper also assumed a fixed weigh battery pack. On the second stage electron tosses one of it's battery packs overboard. Also raw performance isn't as critical for the first stage. One other thing, electric feed has much simpler plumbing than a turbo pump feed. Ans: Maybe, but I have no idea.
  • MichaelMoser123 6y ago
    Interesting, do you have a link to that paper? I guess the regular engines that are running inefficient fuel cycles to power the fuel pumps aren't too weight efficient either, due to the inefficiencies of these fuel cycles. Interesting why this approach wasn't tried earlier.
    • Gibbon1 6y ago
      Took a bit of searching but I found it again. https://www.aacademica.org/hernan.emilio.tacca/9.pdf https://www.aacademica.org/hernan.emilio.tacca/9.pdf If I remember correctly simple turbo pump feed engines have to run using a lot of excess fuel. Simple designs just dump the turbine exhaust overboard. That represents a fair amount of wasted energy. Advanced designs feed the exhaust back into the engine. I think they also scavenge some energy from cooling the nozzle.
      • MichaelMoser123 6y ago
        thanks!