High-performance baffles are required in the operation of space sensors mounted aboard a satellite to track stars for attitude control or to identify the sky region aimed by a paralleled X-ray telescope. For example, on a typical X-ray observation mission, the star sensor shall identify stars in a 8 deg by 8 deg field of view down to the 6th magnitude, even when very bright sources (as the sun or the earth horizon) are only 10-15 degrees off the field of view. This corresponds to attenuate stray light down to approximately 10-9, what calls for a very sophisticated design of the optical baffle and also is an unusual requirement for the measurement of attenuation in the test-laboratory to validate the baffle before launch.1,2.
"Measurement Of Light-Baffle Attenuation By A Gating Technique", Proc. SPIE 1165, Scatter from Optical Components, (2 January 1990); doi: 10.1117/12.962848; https://doi.org/10.1117/12.962848