Punch a third hole on the opposite short side it should be centered and near the bottom. The holes should be large enough for a pencil to rotate easily. Play around with the position of the stopper to get the maximum angle and distance for your launch-and have fun with colors and decorations. This simple machine uses stored energy (the tension in the rubber bands) to release a projectile (called the payload).

Note: If after some use, one of the straws cracks, simply replace it with a new one. Bend the flexible straw to aim and place the rocket straw over the end. Add this to the top to seal the straw completely. Add washi tape to decorate the straw if desired.

(Budding engineers take note: This is called pneumatics!)

This rocket from Ana Dziengel of Babble Dabble Doo uses the power of compressed air to launch into the sky.