QUESTION:
What kind of error-correcting code(s) will be used in the data transmission
of the Cassini orbiter to Earth?

ANSWER from FAQ on June 3, 1999:
We use two error-correcting codes on our telemetry from the Cassini
spacecraft to Earth:
  
1) A convolutional code, either a (k=7,r=1/2) or (k=15,r=1/6) code.
Compared to an uncoded channel, the k=7,r=1/2 code is 4.5 dB better;
and the k=15,1/6 code is 2 dB better than the k=7, r=1/2. The
convolutional code typically provides a BER (bit error rate) of 1 per
200.
  
2) A Reed-Solomon code, which is a block code (255,223), is also used
in combination with the convolutional code (that is, the spacecraft
first does the Reed-Solomon encoding of science data, and then does the
convolutional encoding of Reed-Solomon symbols; we call this
arrangement a concatenated coding scheme). The BER of the concatenated
code is 1 per million or better, which is what the Cassini project
needs.