All long range transmissions use forward error correcting codes which allow error detection and data recovery without retransmission (to a certain degree). See

All long range transmissions use forward error correcting codes which allow error detection and data recovery without retransmission (to a certain degree). See [1] (paragraph 2.5 on page 10) for a bit more on the kinds of FECs used. [1] http://deepspace.jpl.nasa.gov/dsndocs/810-005/208/208B.pdf http://deepspace.jpl.nasa.gov/dsndocs/810-005/208/208B.pdf