Attention to Detail
Apparently,since it was in the making over 2 1\2 yrs.the script became literate and coherent for a wide theme as this covers especially when one goes planet hopping !
Explanations are given at every turn why and the wherefores;that is why the lab scene early in the story helps where Cal and his asst.assemble an interociter and it dwells on it for a lengthty bit of time for it helps the viewer grasp somewhat the technics of this sci-fi classic and better appreciate the suspension of disbelief in rescuing another planet !