Talk:In-Situ Propellant Production

Aluminium

Yes, indeed. Aluminium.

Well, Aluminium's high melting point as a propellant could be overcome if it is added to the fuel mix as nano particles.

Nano aluminium is highly explosive even at room temperature.

Using small particles of aluminum is approximately was done in making the aluminum liquid/oxygen monopropellant referred to in the article. There is a reference. It was tested and the flame did not move backward from the combustion chamber to the fuel tank. I do not think that nano particles were used. The problem was solved in a way but it still remains to be determined if a practical rocket based on this fuel can be launched from Luna. I know that NaK can be handled by pumps at high temperature. Whether it could still work with a rocket fuel pump and some aluminium and/or Magnesium dissolved into the NaK to make a better specific impulse rocket fuel, I do not know. There would need to be some rather difficult to perform experiments made on Earth to find out. What is required is money and the money ought to be spent for the most critical information related to industrializing Luna for a profit. If we achieve profit, settlement will follow. I do not think settlement is a prerequisite for profit. - Farred 05:40, 21 May 2012 (UTC)

Methane, Ammonia

Why the statement that these propellants require no oxidizer? They are not monopropellants and do require oxidizer. Was the intended meaning that they require no oxidiser additional to the oxygen extracted from the volatiles? To make this point, some breakdown of lunar volatiles composition would be helpful.

This statement about not needing oxidizer is not a statement that I am proud of. Solar thermal rockets do not need oxidizer because they work by heating a propellant with solar power and ejecting the hot gas through an expansion nozzle for thrust. It does not use chemical energy for heating and so needs no oxidizer. However suggesting the use of ammonia and methane as rocket fuel would make no economic sense since these compounds would be expensive and rare on the moon. When industry is established on the moon nitrogen compounds and carbon compounds will be in great demand for other things than rocket fuel.

Solar thermal rockets would be possible for use in space but not for lifting off the surface of the moon. They have insufficient thrust to weight ratio for that. - Farred 21:38, 26 March 2014 (UTC)