In the scope of a leading industry aircraft manufacturer suborbital tourism spacecraft preliminary design phase, a conception tool, including design parameters database, vehicle 3D CAD model, aerodynamics analysis, and trajectory simulation, is developed to assess and guide the design of the virtual prototype. The study is realised in an integrative framework, including a concurrent design facility (CDF), allowing the capability to share efficiently data between the various teams designing the different sub-systems, the vehicle geometry model being central in this case. The 3D computer aided design (CAD) model is used for sub-systems implementation and integration. Parametrising the geometry allows to assess the mutual influence of sub-systems concepts changes, during the various design iterations loops. The strategy to build up the aerodynamic database of the global system, where the trajectory simulation model gathers the aerodynamics related information, is to extensively use computational fluid dynamics (CFD). For this purpose, the geometric model of the spacecraft skin is passed from CAD software to a pre-processor for a meshing phase. The advanced and modular capabilities of multi-block meshing are used to generate structured meshes for the various configurations of the spacecraft. A fully aerodynamically validated in-house CFD code is employed to compute the airflow. The computational tools are fully parallel using the standard MPI protocol and are combined with the use of a specific database format to store the information, allowing optimal computational time to solve the hundreds of specific flight points. Computational grids have typical sizes about seven millions of cells. The CFD results are then exploited to assess the aerodynamic forces evaluation which are fed to the trajectory software. Post-processing tools based on the same computational database structure allow for rapid and accurate finer post-processing. Such procedures allow detailed zones to be monitored using the related visualisation software. This design tool is illustrated here to evaluate geometric modifications influence on the spacecraft and mission performances of a suborbital flight concept.