The science is actually sound. Some other commenters clearly didn't take enough physics class.
Creating artificial gravity by spinning the ship and the rocket on the opposite ends and the description of decreasing gravity near the center point of rotation. Also they wouldn't fly away even if they let go on the tether...this is because inertia in space almost never gets decreased since there is no air.
However...the filming is pretty bad. The cinematographer is not skilled enough to do the correct shots. They also never gave a full view of the entire ship in spinning motion so viewers with less science background needs a lot more explanation of what is actually happening...evident byy wife needing lots of explanation...