The International Space Station's cooling system has broke down forcing NASA to arrange an urgent repair. 2 flight engineers were unable to remove the malfunctioning ammonia pump in their first EVA but they succeeded removing the pump by a little hammering & disconnecting the circuit wires in their second EVA after 7 hours & 26 min (It's quite long to fix an air-conditioning unit. Well, it's probably one of the toughest job to do. Imagine, it's already difficult to hold a pen & write in the space suit, what more fix a coolant pump while constantly checking everything including yourself is not leaving the space station. It's a challenging job.) Third spacewalk is scheduled on 16th August to replace the faulty pump.