BAE Systems is to continue manufacturing MK 90 propellant grains for Hydra 70 rockets through 2017 under a U.S. Army contract.

The award, which takes effect next year, is worth $50 million.

"The Hydra 70 missile is the work horse of the unguided missile category," said Reed McPeak, vice president and general manager of Ordnance Systems Inc. at BAE Systems. "It is the most commonly used helicopter-launched weapon system in the world, and we are pleased to fuel this multi-service, multi-national system."

BAE Systems said the MK 90 propellant grain is made at the Radford Army Ammunition Plant in Virginia, which the company has managed since 2012.

More than 300 people in five manufacturing areas at the plant are involved in its manufacture.

BAE Systems began the manufacture of MK 90 propellant grains in late 2012 and has so far delivered about 500,000 grain units to the Department of Defense.