The last time I was there, the apron in front of the terminal at Easter Island could take 2 787's comfortably with H&S observed, and as Treadigraph mentioned in a push with creative parking you could probably get several others in Tetris-style ;-) and there's a hardly used military apron that could squeeze a few in. The issue as I see it would have been slowing the Shuttle down enough not to have gone into the drink at either end and the same at Madeira, bearing in mind the lengths of runway involved in comparison to Edwards. On both landing and taking off my aircraft used all available runway, though not Russian/Ukranian all available. The Shuttle would have most likely have been compromised in some way in needing to divert, which would add another level of limitation to stopping within the allotted runway length. Add in the time-lag in getting NASA technicians/recovery crew to the location and you'll forgive me if I'm a bit pessimistic about the astronauts chances back then. That said, the Canadian A330 that did the near impossible across the Atlantic at night to land at Lajes managed it, so who knows!