- Place the parts of the rocket you want as stages.
- Click the button in the bottom right that says "Stage Mode". Stages work from 0 to 5, 0 staging first and 5 staging last.
- After clicking on the given number, click on the parts you want on that stage. The part should then turn a different color.
- When done building, launch. Press space to activate the next stage. Remember, 0 to 5.