Design a rocket to meet the needs of your chosen mission. Every rocket needs an engine, fuel and a payload — boosters help — but parts that are too bulky or too heavy might not get you far off the ground. Then fly it: throttle, steer, separate your stages. Can you escape Earth’s gravity, get into orbit, and even make it to Mars?
Each mission needs a particular payload and a certain amount of speed. This Earth is a tenth of the real one’s size (with the same gravity and air), so a flight takes minutes, not hours.