When Icelandair started nonstop flights to Denver in May 2012, Reykjavik wasn’t necessarily a top-of-mind destination. But the route helped introduce thousands of Colorado travelers to steamy soaks in the Blue Lagoon and frosty searches for the northern lights. Now that Turkish Airlines has launched a nonstop flight between Denver and Istanbul three times a week, with plans to go up to four times a week next month, what might be in store for Colorado travelers? For starters, Turkish Airlines will provide discounted “launch” fares starting at $787 on roundtrip tickets purchased by July 3 for travel through July 20.