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Possible specification for a Falcon XX to lift sections Mars bound vehicle to space

Discussion in 'SpaceX' started by Peter Egan, Jan 2, 2016.

  1. Peter Egan

    Peter Egan Member

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  2. ecarfan

    ecarfan Well-Known Member

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    I do not see your attached graphic using Tapatalk in iOS.
     
  3. rabar10

    rabar10 FFE until Model 3

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    Source?
     
  4. Peter Egan

    Peter Egan Member

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    Having studied the report of the NASA commission that did the "trade" studies for the SLS and info on the NASA and SpaceX websites, there are three rules of thumb that can be applied for a methane-oxygen powered rocket that represent a state of the art rocket. I derived the figures from the rules of thumb and similar NASA hardware which is well documented. The rules of thumb are 1) - payload to orbit is 4% of the take-off mass of the rocket. 2) - the required fuel is 90% of the take-off mass. 3) - to get from low Earth orbit to Mars, fuel is 75% of the mass of the rocket in low Earth orbit. It means that for every 100 tonnes of rocket on Earth, only 1 tonne will arrive at Mars. SpaceX may be able to improve on these figures a little, but its focus will be reuseability as the natural gas cost for a 200 tonne to LEO class rocket is only around $200,000 ((the cost of the refrigeration and storage plant for liquid methane and oxygen will be at least one hundred times that, and the rocket will cost billions.))
     

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