39 ms·
ISP of Methane in an NTR is less than 600. And the engine, shielding, and cooling mass increases the ship mass at least 2x to 3x over chemical.
by valuearb 6y ago
ISP of Methane in an NTR is less than 600. And the engine, shielding, and cooling mass increases the ship mass at least 2x to 3x over chemical.
- sq_ 6y agoIt's definitely worse than H2's ISP in an NTR, but ~600s is still a solid boost over the ~450s that's about the best a practical LOX/LH2 chemical engine can do. My curiosity is essentially just whether the performance lost between an H2 and CH4 NTR would be gained back through reduced tank mass and boil-off. Shielding/engine mass will certainly be a big mass penalty versus chemical rockets.