3. "First Federation drive", Scotty couldn't identify how it was powered or how it moved ("solid cube"). Logically, if it can't be identified against known propulsion then it must be different from anything known at that time which includes "space warp", "impulse", "ion" and "gravity" propulsion.
4. "Gravity propulsion", from "Obsession"
SPOCK: I should have surmised this. For the creature to be able to use gravity as a propulsive force, it would have to have this capacity.
5. "Ion propulsion", from "Spock's Brain"
SPOCK: Configuration unidentified. Ion propulsion, high velocity, though of a unique technology.