Complex sentence: The original three-book series was called Skipper, Hiker and Climber but this material was updated 2009-2011 and are now called HangGlider, WingRunner and SkyStormer.
Split into simpler sentences: The original three-book series was called Skipper, Hiker and Climber. This curriculum was updated 2009-2011 and replaced with HangGlider, WingRunner and SkyStormer.