"The purpose of the present ""Proof of Concept"" proposal is to investigate the commercial viability of versatile and compact microwavephotonic modules generating high-purity microwave signals and multi-coherent lightwave carriers. These oscillators are expected to core microwave sources in aerospace engineering. Within the framework of our ERC StG project NEXTPHASE (NEXT generation of microwave PHotonic systems for AeroSpace Engineering) which started in November 2011, we had the objective to propose beyond-state-of-the art microwave sources for aerospace engineering applications. The first milestone of the project was the fabrication of millimetre-size whispering gallery mode-disk resonators with ultra-high quality factors. We have developed a unique design capability for such resonators, and we have been able to generate stable Kerr optical frequency combs after pumping them with a laser. The successful generation of such combs is the essential achievement that enables the possibility of commercial multi-coherent laser and microwave sources as described in the present “Proof of Concept” proposal. Our ultra-stable, multi-coherent system is able to generate signals in both the lightwave and microwave spectral ranges and is thereby a promising technological object for aerospace engineering and for other applications as well."