TRYAD: a Pair of CubeSats to Measure Terrestrial Gamma-ray Flash Beams

Abstract:

The Terrestrial RaYs Analysis and Detection (TRYAD) mission is designed to measure the beam profiles and tilts of Terrestrial Gamma-ray Flashes (TGFs) using a pair of CubeSats separated by several hundred km in low Earth orbit. Until now, all TGF gamma-ray measurements have been made from single locations so that there is substantial degeneracy in modeling TGF beams. TRYAD will sample the gamma-ray beam at two locations. Additionally, for many TGFs the source location will be determined using networks of ground-based very low frequency (VLF) radio receivers. With gamma-ray measurements at two positions of known location relative to the TGF source, we will be able to test and distinguish between TGF beam models. Control of satellite separation is essential to the TRYAD mission. Separation control is achieved by using ionospheric differential drag on the two satellites.