I've been experimenting with spaceplanes for the last few days as I'd unlocked the hypersonic tech in science mode. I had managed to get a spaceplane to LKO before but couldn't get it efficient enough to be usefull. Now I'd made a similar version using the ramjet and aerospike instead of the terrier and panther, and lo and behold: it was horrible. Could not even get upto mach 2. With some debugging and using the aerodynamic forces overlay I found out that the aerospike engines where creating an absolutely devastating amount of drag at the speed of sound. Same exact plane can go mach 5+ and get into lko by just replacing them with terrier engines, but the low thrust meant that it does cost most of my fuel. Looking online the aerospikes are loved by most people for SSTO use, so I am not sure what I am doing wrong. What do you guys think? Thanks in advance!