In the frame of the Call for Ideas “H2020-ESA-038 GNSS Evolutions Experimental Payloads and Science Activities”, the project aims at the development of a VLBI transmitter prototype for G2G. It will allow to improve the ties between different space geodetic techniques (GNSS, VLBI and SLR Retro-Reflectors). The activity will contribute to the establishment of accurate and long-term stable reference frames (Inertial and Terrestrial) and to the absolute orientation of the Galileo constellation in inertial space. The inclusion of Galileo satellites with VT into the IVS Intensive campaigns would allow for an immediate referencing of the Galileo orbits to the ICRF through differential measurements with respect to quasars. It will also enable other scientific experiments such as improved relativity parameter determination, time-transfer experiments, ionospheric determination and modelling.