For nearly a quarter of a century, Elon Musk and his essential partner at SpaceX, Gwynne Shotwell, viewed the United States government as El Dorado, the mythical city of gold. Like machete-wielding treasure hunters, Musk and Shotwell hacked through a tangled jungle filled with lurking carnivores such as Boeing and Lockheed Martin, as well as bean counters and regulators…