Complex sentence: A day before the offer's expiration, both Lockheed Martin and Austal USA received Navy contracts for an additional ten ships of their designs; two ships of each design being built each year between 2011 and 2015.
Split into simpler sentences: A day before the offers were set to expire, both Lockheed Martin and Austal USA received contracts from the Navy to build an additional ten ships of their designs. Two ships of each design would be built each year between 2011 and 2015.