We propose to explore the so-far poorly measured cosmic-ray and gamma-ray sky (accelerator sky) in the energy range from 10 TeV to 1 EeV with the new large-area (10 square-km) wide-angle (1 sr) air Cherenkov detector SCORE (Study for a Cosmic ORigin Explorer). The SCORE detector concept is based on non-imaging Cherenkov light-front sampling with sensitive large-area (order of square-m) detector modules, distributed over an array covering a total area of at least 10 square-kilometers. The lateral intensity and arrival-time distribu-tions will be sampled with high sensitivity up to large distances from the shower core. An extension of the SCORE detector to HiSCORE (Hundred Square-km Cosmic ORigin Explorer) is planned. With SCORE (and HiSCORE) fundamental physics questions can be addressed, including the origin of charged Galactic cosmic rays, diffuse gamma-ray emission from the Galactic plane and the local super-cluster, attenuation by Galactic interstellar radiaton fields and the cosmic microwave background and studies of possible effects on this attenuation by photon/axion conversion, hidden-sector photon oscillations or violation of Lorentz invariance. Further motivations are spectral and chemical composition measurements of charged cosmic rays from 100 TeV to 1 EeV and independent measurements of the proton-proton inelastic cross-section overlapping with and exceeding LHC energies. First simulations show that already SCORE has the potential to be competitive with existing and planned experiments above 10 TeV and outperforming above 100 TeV. The physics moti-vations, the detector concept / performance expectations and the status of our project will be presented.