The Catapults High School STEM Boost Kit is a hands-on engineering kit for one upper-level student. Learners build and test a catapult and then design their own original catapult to explore projectile motion and medieval machine engineering, guided by bilingual student guides (English and Spanish). Students first construct a standard catapult design, then apply the engineering design process to innovate and build an original catapult—testing how variables like arm length, fulcrum position, and counterweight affect launch distance and accuracy. All supplies are included—no additional materials or technology required. Works in classrooms, makerspaces, afterschool programs, camps, and home learning environments.