  The Rapid Acquisition Atmospheric Detector (RAAD), onboard the LIGHT-1 3U
CubeSat, detects photons between hard X-rays and soft gamma-rays, in order to
identify and characterize Terrestrial Gamma Ray Flashes (TGFs). Three detector
configurations are tested, making use of Cerium Bromide and Lanthanum
BromoChloride scintillating crystals coupled to photomultiplier tubes or
Multi-Pixel Photon Counters, in order to identify the optimal combination for
TGF detection. High timing resolution, a short trigger window, and the short
decay time of its electronics allow RAAD to perform accurate measurements of
prompt, transient events. Here we describe the overview of the detection
concept, the development of the front-end acquisition electronics, as well as
the ground testing and simulation the payload underwent prior to its launch on
December 21st, 2021. We further present an analysis of the detector's in-orbit
system behavior and some preliminary results.
