Launched in December 2021, Light-1 is a 3U CubeSat whose operation is led by the United Arab Emirates (UAE) Space Agency and assisted by the Bahrain National Space Science Agency (NSSA). It monitors terrestrial gamma-ray flashes (TGFs), which are emitted during lightning storms, to provide insight into how TGFs affect aircraft, their passengers, and humans on the ground.he quality of being luminous; emitting or reflecting light. synonyms: brightness, brightness level, luminance, luminosity, luminousness. see more. noun.