“42” seems to have a few elements working against it: It’s highly reminiscent of “The Impossible Planet”/“The Satan Pit” from Season Two. It coincidentally echoes the movie
Sunshine (which was released some time after this was scripted & shot). It spews rapid-fire technobabble that’s nearly impossible to keep up with. Yet it’s got a massive positive: Its real-time countdown gives it an entertaining, gut-wrenching urgency, so the negatives don’t really matter.