WASHINGTON (Reuters) - The Iraq war proved how essential weather, communications and targeting satellites are to the U.S. military, and that is good news for a U.S. space industry still reeling from a devastating slump in the commercial market, analysts and defense officials said. Over the next decade, top satellite makers like Boeing Co., Lockheed Martin Corp. and Northrop Grumman Corp. will vie for multibillion dollar orders as the U.S. military upgrades or replaces nearly all its satellites. Satellite launchers could also see a lift, given strong military demand and a modest recovery in commercial demand expected in two to...