System for ventilating inside a protected test vehicle with an area for carrying contaminated probes

The system has a pressure cascade provided between a space, vehicle internal space (2) and an environment (9), where the space accommodates contaminated samples, and an interior space is separated by the space for safe admission of a crew. A supply air blower (12) creates as inner positive pressure in the internal space for the environment, where positive pressure is present in the space opposite to the internal space. A set of pressure relief valves (5, 6) and filters (5.1, 6.1) are integrated between the internal space and the space and between the space and the environment.