What is PolCube? The proposed PolCube mission is an international collaboration between NASA Langley Research Center and the Korea Astronomy and Space Science Institute (KASI). The goal of the mission is to validate ocean and air polarimetric science measurements from a CubeSat. PolCube is a contributed, flight-readyinstrument & spacecraft. It is based on the PolCam polarimeter onboard theKorean Pathfinder Lunar Observatory (KPLO).