BepiColombo's radiator is used to radiate unwanted heat from the spacecraft. To avoid the radiator getting overwhelmed by heat from the planet Mercury below it it is shielded with specially shaped titanium fins. These work like everyday Venetian blinds to screen out the Sun, which can look closed when viewed from one angle and open from another. These fins are carefully angled so that spacecraft heat passes straight through them, while high-emissivity, lower-wavelength planetary heat gets reflected away. The left view shows the equivalent mirror-like view from Mercury, and the right view shows the opened-up view from deep space.