not rocket science
- easyRequiring minimal effort
- simpleFree of complexity
- straightforwardClear and uncomplicated
- obviousEasily perceived, unmistakable
- basicFundamental in nature
elementary · child's play · no-brainer · piece of cake · walk in the park · cinch · breeze · snap · doddle · pushover · uncomplicated · effortless · plain · clear · intuitive · common sense · ABC · beginner
difficulty/complexity
not rocket sciencerocket science
Spacecraft propulsion engineering
brain surgery · quantum physics · nuclear physics · astrophysics · incomprehensible