 Once the burn was completed, the module was to be jettisoned, and would burn most of its mass up as it reentered the atmosphere.The cabin of the CRV was designed to be a "windowless cockpit", as windows and windshields add considerable weight to the design and pose additional flight risks to the spacecraft.Instead, the CRV was to have a "virtual cockpit window" system that used synthetic vision tools to provide an all-weather, day or night, real-time, 3-D visual display to the occupants.