Since we're on this major thread drift, I'll throw in my two penn'orth. They do have something in common however, since they are both undulating and it is difficult to find space to build a runway, though in Easter Island's case, there was a little more flat land. I've been there and there is a plaque on the wall of the terminal building, which commemorates the visit of a group of astronauts, (can't remember which ones now), presumably for training purposes. I agree with treadigraph that the logistics would be challenging, particularly since there is no conventional port on Easter Island. The topography reminds me in many ways of Ascension Island, which was also NASA-designated and also does not have a conventional port. I have often wondered precisely what would have happened if the space shuttle had been forced to land at one of the the many such designated airfields around the world.
Back to Madeira and of the two islands, I actually prefer Porto Santo, though there isn't a lot to do there.