Much of Part 2 of John Millerman's lavish and ambitious The Uranus Experiment is devoted to sex back on Earth, but it is still entertaining and quirky XXX sci-fi.
In the 2009 DVD compilation titled Private Classics 4: The Uranus Experiment, much of Part 2 is relegated to bonus material as Deleted scenes, indicating its lack of relevance to the overall saga. But I enjoyed Part 2's focus on the wife of US Commander Dirk Lang, played by Gabriella, suffering back home in a porno version of the recent TV series The Astronaut Wives club.
Other highlights include the 6-person orgy in space; a hot lesbian segment of girls cavorting in a sauna; and a cliffhanger ending when Lang arriving on the surface of Uranus meets two blue-skinned female creatures, who blow him memorably.
It's well worth watching all 3 parts together, though Part 1 has been cannibalized into that composite 2009 edition marked above. It's the segment which contains the brief but impressive "weightless cum shot".
