All excited about finding out about something apparently worth watching, I checked Netflix to add
Voyage to the Planets to my queue and lo and behold - I'd already seen and rated it. A big two stars outta five.

And I'm not a tough Netflix reviewer (practically everything gets at least four stars).
And now I remember seeing a very pretty show about planetary visits that was ruined by having a dumbshit soap opera with silly characters and a poorly written plotline superimposed on it. Contrast that with, say,
The Universe's episodes on Mars or "what would Earth be like without the Moon," which are absolutely absorbing without the need to add some silly story to what should be fascinating material for anyone with even a passing interest in the wonders of the cosmos. Rather than watch the antics of fictional characters, I would much rather listen to real-life astronomers talk about the topic, and convey the wonder and love they have for their profession. That's all the "human interest" we need.
The one clear advantage of
Voyage to the Planets is that it's two hours long and the sparse story and paper-thin characters don't have (as much of) a chance to wear out their welcome. Pretty SFX doesn't constitute good fiction.
Voyage to the Planets and
Defying Gravity have the same problem - they need to make the audience give a shit about the characters and their situation to keep tuning in each week. But
Defying Gravity is worse because it didn't give us the pretty SFX to serve as some compensation.
And what's the point of ruining a perfectly good documentary topic by dumbing it down for the masses like that? It's not even necessary, since the History Channel does fine with a pure-documentary format - yes, people WILL watch a "boring" show about Neptune, dark matter or whatever without sugar-coating at all. With the new season of
The Universe underway, I'm pretty much set for my wonders-of-the-cosmos documentary needs. But I still need a worthwhile space opera series!
The creators of
Defying Gravity should have recognized that the rules for them are the same as the rules for any other type of show. You start out with an interesting story and characters worth watching.
And, although I'm willing to give em some leeway about the silly-science problem, neither show really addressed the fundamental problem of the premise, which is that manned expeditions to hostile planetary environments make no sense because any scientific information could be gathered more efficiently by probes, robots, etc. There is no reason to put human life in danger except for PR or political purposes (which was the real motive behind Apollo 11). Rewrite the premise to make the mission be all about Earth politics, and then I could believe it. Or come up with a profit-driven scenario. But pure science? Pshwah!