Neither NASA Nor DARPA is that stupid to play their best cards. Their best nuclear and plasma designs are with held from public disclosure. Where I’m coming from is the survival of the human race as a species overrides national interests. If I can improve motor designs released already then it is assumed they have their own improved designs as Aces up their sleeve and are better than the improvements I drew. These two pictures in more detail show first of all NASA had the means to lob into orbit A nuclear space shuttle without staging while Verner Von Braun was still alive. The Mach 20 Ramjet had to await 3d laser melt of interior refractory components because the burn of H2 plus o is 4,500 degrees, past the year 2000.