The Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO) is a novel Explorer-class concept for a next-generation telescope covering the poorly explored hard X-ray and soft γ-ray energies (0.1 MeV – 10 MeV). This concept builds upon the heritage of past and current missions, improving sensitivity and angular resolution. GECCO uses the combined Coded Aperture Mask and Compton telescope techniques to employ the benefits of both: superior angular resolution provided by the Coded Aperture, and good background rejection and wide field-of-view provided by the Compton telescope. It is being developed at NASA/GSFC in collaboration with other US and foreign institutions. GECCO observations will extend arcminute angular resolution to high-energy images of the Galactic plane, and will make a bridge between X-ray optics instruments and the high-energy γ-ray instruments, enabling a broad potential for discoveries in the MeV γ-ray sky.
