End-to-End Mission Performance Simulators for Earth Observation missions are one of the prominent tools for system design and scientific validation in early mission phases. The European Space Agency has promoted efforts to exploit synergies between activities and reduce engineering costs in mission planning. The main goal of the BIBLOS project is to provide a library of software units called “Building Blocks”, or simply “Blocks”. These blocks could then be integrated into modules, following the reference architecture developed in the frame of the ARCHEO-E2E project, in order to build an End-to-End Simulator in an efficient manner. The first stage of BIBLOS project, referred to as EOMODEL (or BIBLOS-1) and, focused on Passive Optical instruments, was successfully finished (in April 2016) with the geometry, scene generation and instrument modelling of optical imagers, which are one of the most frequent types of passive optical instrument on Earth Observation satellites. BIBLOS-2, which is the second stage of the BIBLOS project, is a currently finished activity with the purpose of expanding the BIBLOS library to include Passive Microwaves instruments and Active Microwaves instruments. Additionally, as part of a continuous improvement process, this second stage of BIBLOS has also updated some of the most computational performance intensive blocks for Passive Optical instruments with parallel implementation for Graphic Processing Units. For BIBLOS-2, the Sentinel-1 and MicroWave Imager (MWI) instruments have been selected to develop the building blocks for Active Microwaves and Passive Microwaves instruments respectively. During the BIBLOS-2 stage the full simulation chain has been developed for Passive Microwave, starting from the Geometry Module, through Scene Generation and Instrument Modules and ending at Level 1 Processing Module. For Active Microwave Instruments this stage of the BIBLOS activity is focused on the Geometry Module and the Performance Evaluation Module only. Special efforts are devoted to adapt the Geometry Module for monostatic, bistatic and multistatic missions in various configurations and with different a number of microwave instruments. In addition, the Performance Evaluation Module is in charge of evaluating the performance figures and providing plots, such as diamond diagram, ambiguity area and ratios, Noise Equivalent Sigma Zero and antenna radiation patterns. This paper presents the work successfully carried out during the BIBLOS-2 stage, currently performed by GMV under ESA contract.