Currently, there is no way to alter the gravity coefficient for objects from the standard in the engine -- a similar effect is achievable through tons of scripting however often destroys performance for most, changing at an engine level would be ideal over this.
While not necessarily useful for most people, it would give a lot to groups who reside in the sci-fi area of the community, and possibly allow for units to continue and explore the Contact storyline in their own unit's lore