I am not sure if they are random words. Spaceyacht is synonymous to spaceship. Appreciate your input.Reg fee you have 2 random words together. I see spaceyacht non plural as music site so going to be working their brand. I wouldn't try this tactic with brands it only suits generic. Even without TMs no point working another's intellectual property.
You need to learn the meaning of term yacht. It doesn't necessitate water to be the medium of travel. Google 5 billion dollar space yacht.