Nox: a SmallSat mission concept for characterizing all-sky Lyman-UV background

Nox is a SmallSat mission concept designed to characterize the Lyman-UV (LUV) background across the entire sky. Despite the growing interest in LUV observations in orbit, the spectral and spatial distribution of the LUV background remains critically understudied. Without knowledge of background radiation, planning a future mission for detecting faint diffuse emissions becomes challenging. The Nox mission concept has been developed to bridge this gap by characterizing the background radiation in the LUV. Utilizing state-of-the-art UV coating, grating, and detector technologies, Nox aims to deliver unprecedented foundational data in the LUV landscape through spectroscopic all-sky observation in the 90-115 nm wavelength range using a wide-field, low spectral resolution spectrograph with a 2.5 degrees by 1.2 arcmin field of view and R ~ 1,000. In this poster, we describe the motivation of the mission, along with the conceptual payload design and the baseline optical design.