5 DRS Technologies says its purchase of Engineered Support Systems (ESS) will boost its revenues to $2.5 billion in 2006, up from approximately $1 billion for the Parsippany-based defense contractor in fiscal 2004. ESS, a military products and services supplier based in St. Louis, reported revenues of $883.6 million for 2004. The $1.8 billion merger pumps up DRS' employee count to almost 10,000.