From TeachEngineering - Students revisit the Pop Rockets activity from Lesson 3, in which mini paper rockets are powered by the chemical reaction of antacid-tablets and water in plastic film canisters. This time, however, the design of their pop rockets is limited by budgets and supplies. They get a feel for the constraints of real engineering projects as well as the opportunity to redesign and retest their rockets to make improvements. Rocket build instructions as well as activity-guiding budge