Led by Belgian Institute of Space Aeronomy with VTT Finland and Clyde Space, UK, PICASSO is a 3-unit CubeSat mission to measure Stratospheric Ozone distribution, Mesospheric Temperature profile and Electron density in the ionosphere using a miniaturised multi-spectral imager for limb sounding of solar disk, and a multi-Needle Langmuir Probe, due to be launched in 2016 on the European Commission's QB50 flight.