I expect reasonable efficiency with tax dollars once you have a viable system. But as ANY R&D department knows - public or private. 80% of an R&D budget tends to go nowhere. It’s the 20% that produces “new art” that advances civilization.
Sailors with solar sails are not going to tell you anything about long duration solar panel systems in space getting bombarded with particles and radiations that the earth’s atmosphere absorbs. You gotta go try it.
And there will be blind alleys and leapfrogs. I think it was a Ray Bradbury sci-fi story that described a mission to Alpha Centuri where the crew were put in a state of chemical suspended animation so they would still be young when they got there. Though only 4.3 light years away - the fastest spacecraft was still going to take thousands of years to get there. When they arrived they were greeted by humans. A “warp drive” had been invented after they departed and later generations got there first.