A serious question for muslims?

I am educated in muslim customs and practices, but on reading about Muslim astronauts, I just have to ask this.... I know that Muslims all over the world when they pray face Mecca. Where I live that would be generally east southeast. In space there really isn't much for directions, so, I must ask, in space, how would a muslim hep the 5 prayers and what direction would the astronaut face? Or in space does it really matter as it would be quite dificult to achieve the proper positions for prayer?