Solar atmosphere causes difficulties in communication during opposition (when Mars is almost behind the sun w.r.t. Earth).
The question is: is it possible to define an extended radius for the sun, which the Earth-Mars line of sight should never pass through it? if there is, how much is it, in terms of angular separation?
I've read in some mainstream and NASA news that there is a two week blackout period during each synodic period of Earth-Mars. But I want to know the exact numbers. I'd appreciate any answer with technical references.