FYI, I just gave this a try and it seems to work! More specifically, my steps were: 0) make a backup! $ cp KSP.x86_64 KSP.x86_64.bak 1) figure out the byte offset where the particular Intel string shows up: $ cat KSP.x86_64 | xxd | grep "Intel" 0f01f00: 454c 0049 6e66 6f6f 0025 692e 2569 2e25 EL.Intel.%i.%i.% 0f024f0: 2049 6e74 656c 2039 7878 2028 6275 6767 Intel 9xx (bugg That first line is the one you want (as GeneCash points out), figure out what that is: $ printf "%d" 0x0f01f00 15736576 then add a few bytes to get exactly into that "Intel" string, in this case about 5 bytes should do it 2) replace those bytes (thanks to StackOverflow: http://stackoverflow.com/questions/4783657/cli-write-byte-at-address-hexedit-modify-binary-from-the-command-line) printf 'foo' | dd of=KSP.x86_64 bs=1 seek=15736581 count=3 conv=notrunc 3) profit! as GeneCash points out, you should see a shadow behind the kerbal on the Mun at startup.