"We were over-hasty," Karl agreed. "Whole space effort has been. Those early scramjets, they were deathtraps." He shook his head. "Both sides. The Yankees kept trying to model the airflows with inadequate computers, and we, we built a gigawatt of nuclear power stations, used the whole Dniester for cooling, to get that damned Mach-18 quarter-scale windtunnel. And we still had disasters."
For the curious, this appears to be:
"The Stone Dogs (1990) by S. M. Stirling [...] third book in the alternate history series, The Domination."