IIRC there was also at least one DoD contract in the Falcon 1 era that surely helped as well. I recall reading a few references to it and remarking how odd it was. Some real invisible hand stuff. Since then I've noticed one other project was sustained by military contracts. EMC2 (polywell fusion) got several years of support from the US Navy via small (few $million) contracts. Last I read, they had validated the physics and were looking for civilian investors to fund a large machine.
The US government has pots of money they use to buy flights on unproven rockets, that's how SpaceX got a contract for STP-2 as the 2nd flight of Falcon Heavy. Falcon 1's first two flights got some revenue from DARPA and the Air Force ORS, and flight 3 from NASA. (All failed.)
