In my ongoing research, I've run across various terms like "high energy gas" as a reference to the propellant. My research primarily concerns developments in the 1950s. So, aside from liquid oxygen and liquid hydrogen, what other gases were used? On a related note, aside from nitiric acid and hydrazine, I've also seen references to propellants containing a copper compound. Any books, articles or other leads on the latter would be much appreciated.
Thanks,
Ed
Thanks,
Ed