In the old days of satellite development (40 years ago at Hughes Space & Communications), I observed that the bit order in digital subsystems was always Big End

In the old days of satellite development (40 years ago at Hughes Space & Communications), I observed that the bit order in digital subsystems was always Big Endian, but all the other subsystems were usually Little Endian. Sometimes this caused issues, which fortunately were discovered during the integration & test phase. Usually problems like this were "corrected" by altering the documentation instead of the hardware so for a while, the majority of satellites in Earth orbit had a strange mix of endianness throughout the subsystems. The digital culture eventually won at Hughes/Boeing, but the standards committee punted and allows the endianness to be arbitrary (as long as it's documented) in the CCSDS standards. https://public.ccsds.org/default.aspx https://public.ccsds.org/default.aspx