True. Launch loops are "just" an engineering problem which could be built with known materials but in reality the engineering problems are so huge it's hardly

True. Launch loops are "just" an engineering problem which could be built with known materials but in reality the engineering problems are so huge it's hardly any better than space elevators which call for undiscovered materials. You also have the associated economic problems; the up-front cost of a launch loop would be so huge that you could never convince anybody to build it instead of using rockets. Fusion has the same problem; even if you can design a fusion power plant that produces net power, it needs to produce net power by a massive margin to have any chance of being economically competitive with fission let alone solar.