He's a devout Muslim and when he says his daily prayers he wants to face Mecca, specifically the Ka'aba, the holiest place in Islam ("Turn then thy face towards the Sacred Mosque: wherever ye are, turn your faces towards it .... " The Quran, Al-Baqarah, 2:149).
That's where the trouble comes in. From ISS, orbiting 220 miles above the surface of the Earth, the qibla (an Arabic word meaning the direction a Muslim should pray toward Mecca) changes from second to second. During some parts of the space station's orbit, the qibla can move nearly 180 degrees during the course of a single prayer. What's a devout Muslim to do?www.wired.com