Following on the theme of marshmallows. We set up a small competition for building catapults. Firstly, we went through the upcoming engineering news including sail drone’s autonomous sailing boats and the launch date for Musk’s Falcon 9 Heavy. We then took the society through how catapults convert potential energy to kinetic energy very quickly in order to cause a damaging blow to an enemy. With the science explained, the group set about building their catapults out of lollipop sticks, plastic spoons and rubber bands (with the marshmallows as projectiles). After a 12 minute build, the designs were ready to fire, We had each of the catapults compete in two events, distance and accuracy. The accuracy of the catapults was not all to great with the winner being 70cm away from the target (firing form 2.5m) but the distance showed a much better promise. Each catapult shot further until we were left with the winning group whose marshmallow comfortably cleared the length of the room, about 7m, before hitting the wall on the other side and landing. Finally, the winners of each category got to eat some of the leftover ammunition to celebrate their victory.