Forrest Mims' Science Experiments

Chapter 23 Use LEDs to Track Night-Launched Projectiles

Model rockets and toy projectiles sent aloft by rubber bands or slingshots are loads of fun. While model rockets are best for high altitude, you can have plenty of fun launching inexpensive projectiles equipped with a steady-state or flashing LED to fly at night. You can stage competitions to see how far various designs can travel. And you can do some real science by recording their flights with a time exposure camera to study flight stability, spin, and speed. Let’s get started with an ultra-simple projectile launched with a slingshot.

Slingshot Micro-Light Rocket

Hobby Lobby stores sell a package of a dozen miniature white LEDs installed in tiny metal cylinders equipped with a battery ...