# What lights to use for a high-altitude weather balloon?

I am designing a high-altitude weather balloon for a college project. The balloon may fly at night, which means that, per FAA regulations, I need a light that is visible for 5 miles.

Does anyone know how to calculate this? Or knows some cheap and lightweight LED lights that work for this application?

• Search on AircraftSpruce.com for anti-collision lights. They aren’t cheap, starting around $500. Since it is just a project, you won’t need a TSO version. This one is lightweight and says "Exceeding all TSO intensity requirements" aircraftspruce.com/catalog/elpages/… – JScarry Mar 16 '19 at 14:09 • hmmm$500 is our entire budget haha, but this has given me a good place to start! Thank you – Timothy Barrett Mar 17 '19 at 17:23