The reason for the triple redundancy is that solar radiation can cause bits to flip e.g. from 0 to 1, which can completely throw out calculations. So, there have to be a number of cores in agreement so that if one of the cores has been affected by a bit flip, it can be detected.
Una vez leí que en el espacio las ondas cósmicas (?) pueden alterar los bits, supongo que por eso los de space x corren la misma instrucción en 2 cpu y luego comparan el output.
https://t.co/HrpmOtQNz7