Universitat Politècnica de Catalunya (UPC) – BarcelonaTech Remote Sensing Laboratory focus on the development of breakthrough concepts. The 3Cat-2 mission is on the synergy of GNSS reflectometry and the CubeSat concept. Scientifically valuable mission data will improve our understanding on the Earth’s environment. In particular, ocean currents need further investigation because of the spatio-temporal evolution of the mesoscale phenomena. The spacecraft development work includes two stratospheric flights in the frame of the REXUS/BEXUS programme coordinated by the European Space Agency (ESA). Coherent and incoherent scattering of Earth-reflected GNSS signals as sensed by the P(Y) & C/A ReflectOmeter (PYCARO) payload will be evaluated using the main state-of-the art Global Navigation Satellite Systems Reflectometry (GNSS-R) methodologies. Future space-borne activities could take advantage of it, including the GNSS REflectometry, Radio Occultation and Scatterometry onboard International Space Station (GEROS-ISS) experiment