Since 2013, COSMOS has added a new and fun feature to its weekend programme that anyone can take part in: build and launch an air+water powered bottle rocket! It's a very simple and rewarding addition. Simply get a 1.5 or 2 litre fizzy drinks bottle (7Up and Club branded bottles work best due to their neck and collar design), craft it with your own imaginative rocket design, using the neck as the exhaust, and bring it along on the Saturday. During the extended lunchtime break, there is an opportunity to watch your rocket soar from our custom-made launch pad, engineered by Bob Campbell, using a combination of water and high-pressure air. Which rocket will soar the furthest?