The NUSAT-31 (RUBY PAYNE-S), also known as Ruby Payne-Scott, is an Earth observation satellite operated by URUGUS from Uruguay. It was launched on May 25, 2022, using a Falcon 9 launch vehicle from Launch Complex 40 at the Air Force Eastern Test Range. The satellite has dimensions of 0.813 meters in length and diameter with a dry mass of 38.5 kg. Equipped with an imaging payload and LUSEX U/V linear transponder, it is powered by solar cells and batteries. With a mission duration expected to last between 3-4 years, NUSAT-31 aims to provide Earth observation capabilities for its owner URUGUS.