Why are polar codes not being used in space communications (error correction)?

Question

From what I have read, satellite communications work mostly using turbo codes since the 90s, but most recently (2009) the polar codes were developed, which seem to be also faster and easier to implement.

These are being used by Huawei's 5G network. But I don't seem to find any good case where this new type of error correction is being applied to space communications. Why?

Answer 1

1. Return on Investment: it's an improvement if a channel code is better, but convert the code improvement into money saved, and put it into perspective with the overall system costs, it's suddenly not that pressing anymore
2. Time Scale: if you put something on a satellite, it better be proven, because you won't be able to repair it once it's in space. 2009–2018 isn't really long on the time scale for aerospace components. There's no immediate need (see previous point), so why switch to new codes?
3. "They seem to be easier to implement": as someone who maintains an implementation (didn't write that myself, a very talented friend of mine did), I don't know if I agree to the "easier to implement" at all. That thing is complex. Anyway, that's a false benefit. Other codes were already implemented and tested, and not something easy is still easier than implementing it

Polar codes are cool because they are rate-achieving. But in many cases of satellite communications, we can use pretty long block lengths, and that makes classical codes relatively good! So, for those links, the benefits of theoretically better codes is smaller than for let's say highly multipath highly changing channels like the one you'd see in a mobile cellular terrestial system.