It's worth noting that GPUs have a much higher failure rate than traditional CPUs. Over 10x the failure rate due thermal stress. The amount of heat generated is very different. You can't really replace a GPU in a satellite (at least today?) which would place most of these satellites as space debris in a ~5 year horizon.
Usually satellites utilize an older node as newer nodes are easily bit-flipped by radiation. And blocking radiation is heavy.
AI calcs may handle wrong calculations better than cpus where software will tend to panic.