What is firefly?
Firefly is a small satellite launched by the National Science Foundation and various colleges. It is small, about the size of a football and is designed to study one of the fastest natural particle acceletors on Earth - lightning!
Firefly is also designed to study beams of electrons and gamma rays that can only be seen by satellites, including gamma ray flashes known as Terrestrial Gamma-Ray Flashes, also known as TGFs.