Most of the really wrong design decisions in the Shuttle system — the side-mounted orbiter, solid rocket boosters, lack of air-breathing engines, no escape system, fragile heat protection — were the direct fallout of this design phase, when tight budgets and onerous Air Force requirements forced engineers to improvise solutions to problems that had as much to do to do with the mechanics of Congressional funding as the mechanics of flight. In a pattern that would recur repeatedly in the years to come, NASA managers decided that they were better off making spending cuts on initial design even if they resulted in much higher operating costs over the lifetime of the program.