Reusable, or partly reusable, launch vehicles have been a goal of engineers for 50 years. Except for the partly reusable Space Shuttle, dozens of projects in many nations have been started, only to be canceled because the development cost was too high, the technology was too difficult, etc. Sometimes the economics have not looked promising, as market projections failed to materialize.
The US Air Force is going to try again. From a posting on Federal Business Opportunities:
"Brief Program Summary: The Air Force has identified the Reusable Booster System (RBS) concept as a promising approach to meet its future spacelift needs. The RBS consists of an autonomous, reusable, rocket-powered first stage with an expendable upper stage stack."
Will the program make it this time? Let's hope so. The Air Force is reacting to the rising cost of expendable launchers. I've been saying for decades that we have to move past the idea of throwing the whole rocket away.