I like a lot the concept! Some ideas:
- The research should take time and resources (not only money, but manpower also). If you want to make more research, you have to hire more people.
- Related to the previous. Make researchers a limited resource. After all, not many people could do that kind of research! There could be an event where a researcher from the other side defected to ours, or the reverse.
- The funding should be related to the following factors: success, media coverage, and the opponent media coverage. The space race started to get really well funded once USA though they were goin to lose the race.
I really hope you succeed in bringing this game to completion. Good luck!