Originally Posted by
Sixth Freedom
According to
Wikipedia (

) it is only 100km from LHR to outer space. Of course it could well depend on where the UFO takes you.
But at a minimum it would be band 1, the same as LHR<>NCL or LHR<>CDG, so I would guess 27k Avios would be the base fare for the UFO's F compartment in low earth orbit.
Your theory takes a nose dive then, as there are no sectors that short flying an F cabin
To be honest, if I'm going to be abducted and travelling in Y then I'd rather not bother.