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Have I got my figures correct?
Christopher wrote in
: Could one of you please check my figures in the below work I have been doing. As I have a feeling my calculations are maybe way short on reflection, as I have used web based conversion utilities, as I never did physics at schoool as physics was never on the schools syllabus. Several thoughts: don't use nuclear thermal except for the final stage; the high Isp is not particularly useful for climbing out of the bottom of a gravity well. High thrust is; use kero/LOX as it's FAR more cost-effective. A 1.5 million lb/thrust NTR means something on the order of a terawatt nuclear reactor. Think about this in practical terms. If you are only going to low orbit, there's no need for NTR at all. Attempting to design a three-stage NTR for low orbit is absurd in too many ways to summarize here. "Fuel" in a nuclear thermal rocket is the uranium/plutonium which provides the heat to expand a "reaction mass", typically liquid hydrogen. Ammonia could be used if higher thrust is desired; it has a slightly higher mass and much better density, is only a mild cryogen, and should decompose into nitrogen and hydrogen to yield a better Isp. Methane seems practically useless in a NTR and only marginally useful in a chemical rocket. Simplicity is a high virtue in rocketry; the more parts the higher the cost and failure rate. Your design philosophy is hopelessly and unnecessarily complex, and reflects a very poor understanding of rocket engineering. Get thee hence to "Rocket Propulsion Elements" by Bruce Sutton or similar books (check on Amazon for used copies) and start learning. --Damon |
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Have I got my figures correct?
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