What are the controls for Kerbal Space Program

W A S D to pitch your rocket up, left, down and right (relative to the nav-ball at the bottom of the screen, not what you can see.)

T will activate your Stability Control System or SAS if one is installed.

R will active your Reaction Control Systems or RCS if they are installed.

Space will advance your rockets staging - firing engines, decoupling spent stages etc. depending on how you have set them up pre-flight.

LShift and LControl affect the thrust of solid fueled engines and jet engines. This does NOT control solid rocket boosters, or SRBs.

The keys 1,2,3,4,5,6,7,8,9,0 will activate anything that you have designated to them pre-flight. Backspace activates the abort sequence - again something that must be set up pre-flight.