For a game I need an "orbital weapon platform"/"orbital weapons platform" and wonder which one is correct, or sounds better for an English native speaker.
It's the singular of a noun that is normally used as modifier for another noun.
Apple will publish the new version of its 64-bit operating system very soon.
The new orbital weapon platform will be operative before the end of June.
If I look at weapons platform on the Corpus of Contemporary American, I find eleven instances of the phrase (with six instances used in fiction contexts), and two instances of weapon platform). Five instances of weapons platform have been used in the period 2005-2010.
"Orbital weapon platform" would be a single vehicle which is launched into orbit to stage a weapon.
"Orbital weapons platform" would be a system or vehicle design allowing many weapons.
So, if it's a Civilization-style technology which the user develops, it would be an orbital weapons platform.
If they launch a number of them one at a time, each is an orbital weapon platform.