UPI almanac for Wednesday, July 25, 2007.

UPI almanac for Sunday, July 1, 2007.

Today is Tuesday, July 25, the 206th day of 2006 with 159 to follow.

Today is Saturday, July 1, the 182nd day of 2006 with 183 to follow.

Today is Monday, July 25, the 206th day of 2005 with 159 to follow.

Today is Friday, July 1, the 182nd day of 2005 with 183 to follow.

Today is Sunday, July 25, the 207th day of 2004 with 159 to follow.

Today is Thursday, July 1, the 183rd day of 2004 with 183 to follow.

WASHINGTON, Dec. 17 (UPI) -- The first powered, heavier-than-air flight by the Wright brothers, on Dec. 17, 1903, ushered in a century of aviation and space history. Here are some other historic milestones that have marked the first century of flight.