The SPRITE cubesat is a recently selected NASA astrophysics mission designed to measure ionizing radiation escape from star-forming galaxies, and to map far-ultraviolet (1000 - 1750 Å) emission from shocked regions in supernova remnants. The instrument leverages a number of new technologies identified for future large mission concepts, including the LUVOIR surveyor, to achieve the required performance. These include high broadband reflectivity mirror coatings and an ultra-low background photon counting microchannel plate detector with an anti-coincidence particle rejection system. SPRITE will serve as a flight testbed for these technologies, employing a robust calibration program as part of the principal science mission to advance the technology readiness level (TRL) to 7+ and provide heritage for future Explorer-class and larger missions. SPRITE is a 6U class cubesat funded through NASA ROSES with an anticipated launch date in 2022. The science data products will be archived on the Mikulski Archive for Space Telescopes (MAST). This proceedings describes the instrument science program, optical design, preliminary performance projections, and project timeline.