Yes, and this StackEx post gets a response about ammonia that quotes Clark's Ignition: https://space.stackexchange.com/questions/22758/reasons-why-liquid-anhydr

Yes, and this StackEx post gets a response about ammonia that quotes Clark's Ignition: https://space.stackexchange.com/questions/22758/reasons-why-liquid-anhydrous-ammonia-fuel-chosen-for-the-x-15-has-it-been-used https://space.stackexchange.com/questions/22758/reasons-why-... AFAIK, IANAExpert, Haber process is very energy intensive and centralized. It would be helpful to crack the N2 in a more distributed manner and harvest the results and maybe in a more rocket friendly molecule than ammonia, like APCP feedstock. https://en.wikipedia.org/wiki/Ammonium_perchlorate_composite_propellant https://en.wikipedia.org/wiki/Ammonium_perchlorate_composite...