Re: Titan, the interplanetary gas station - In-Situ Propellants

"Jeremiah Jones"  wrote in message 
news:[email protected]...

My point is that you think there is fuel on Titan
ready to pump 'n fly.  There is not.  You have to make
your own fuel, like you would on the moon or Mars,
just with different chemistry.

Wishful thinking is not a substitute for science.
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Earth is the only known source of abundant free oxygen to burn fuel, thanks 
to photosynthesis. Separating oxygen from water takes more energy input than 
the fuel burn gives back, and at the distance of Titan solar power is much 
too weak to provide it, a spacecraft that can utilize local methane for fuel 
still needs to carry more energy in some form out than it will require to 
come back.

Obtaining oxygen from water automatically produces hydrogen for fuel.

The weight (mass) that carries that energy is the fundamental limit to 
rocket capability, since the mass has to be lifted and accelerated before 
its energy can be used. It's like how far you can hike with the amount of 
food and water you can carry.
Rocket science:
https://en.wikipedia.org/wiki/Propellant_mass_fraction

If the energy is in nuclear form it can be used directly as heat or 
converted into electricity for propulsion, methane and oxygen won't be 
needed.