This particular show is very interesting, as it might just be the first sci-fi series to mention the concept of black holes. The idea was relatively new---so new that in the show they never referred to them this way but talked about a 'black sun'--though when they describe what it is, it's obviously what we now call a black hole. It's a neat idea for a show and I liked how Professor Bergman and Commander Koenig actually considered that there was a God or some other powerful designing force in the universe. Unfortunately, when they went through the hole, the show, for just a bit, got really goofy! The show begins with a very typical occurrence on the series--one of their Eagle ships is destroyed! Considering that they are stuck on a base and cannot get more supplies from Earth, it's amazing that week after week they kept losing the ships and never ran out of Eagles nor capable pilots! Anyway, the guy was apparently killed by the gravitational forces of a black hole--and Bergman arrives just seconds after the ship blows up to tell everyone to keep their distance! Oops. However, it might all be academic, as the moon is being drawn inexorably into the hole and it's assumed that it will just crush everything. But, in an odd effort to avoid catastrophe, they construct a super-futuristic force field and hope that they'll somehow survive the hole's crushing forces. In addition, they send an eagle with six people in the opposite direction in the hopes that at least they can escape.
My problem with the show happened when they went into the hole itself. Instead of keeping a level head and just coming up with the concept that some force saved them, they felt a need to show the entry into the hole and it was GOOFY. Like the horrible scene of the people flying through tunnels in billowy clothing from the Disney film "The Black Hole", this part of the show was really dumb...and also reminiscent of the end of "2001: A Space Odyssey" (the part where Kier Dullea turns into an old geezer). It's too bad, as aside from this dopiness, the show was pretty creative and interesting.