The original "Manhattan Project" was to produce a nuclear bomb once the physics of sustained nuclear reactions were well enough understood to know it was possib

The original "Manhattan Project" was to produce a nuclear bomb once the physics of sustained nuclear reactions were well enough understood to know it was possible. This level of knowledge was probably known about fusion power generation in the 1960's. As you said, more funding is not always better. It is the whole structure of the project that is important. The Manhattan Project was organized by a military general with direct access to the president and the willingness to use it to get things done and a well known scientist overseeing the scientific side of things. They ran many different paths to possible success at the same time (U235 and Plutonium bombs, at the top level) and had about 130,000 people working on it with the urgency of war and no worries about patents or trade secrets. There were lots of bottlenecks and new technologies to invent in the process, but these problems were systematically addressed and overcome. I don't really think any "Manhattan Project" or Apollo like program run by the government could be done today, but I don't think the US has completely lost the ability to do such things. SpaceX is making amazing progress on rockets at the moment and if they get people to Mars in the next 4-6 years, I would say they have accomplished a similar feat.