Complex sentence: In 2007, the U.S. Marine Corps developed an upgrade to Constant Hawk called Angel Fire, and in 2011, a Constant Hawk spinoff--called Kestrel--began deployment on aerostats in Afghanistan.
Split into simpler sentences: In 2007, the U.S. Marine Corps developed an upgrade to Constant Hawk called Angel Fire. In 2011, a Constant Hawk spinoff called Kestrel began deployment on aerostats in Afghanistan.