True to a point, but I can't think of too many defense aspects to Voyager 1/2, the Viking missions, Pioneer, Pioneer Venus, Galileo, Mars Global Surveyor, Pathfinder, etc.......
There is little technology difference between the solar system explorers and military spy satellites or how they got up there. Since the Stone Age the military has been the primary driver behind “cutting edge/bleeding” technology. And war has been the primary driver of genetic and cultural human evolution. It’s why humans are the most genetically developed animal on Earth despite the late start. Knowing that the need for large amounts of military spending should be evident. World peace is a hippie pipe dream. Human means war maker.