L-3 Communications has received a $44.7 million contract to upgrade, repair and overhaul photonics masts on U.S. Navy submarines.

The contract covers both the Photonic Mast and Photonic Mast Variant, major units supporting the imaging systems on Virginia- and Ohio-class submarines. In addition to repairs, L-3 will provide replacement and repair of mast subassemblies, and also perform testing, inspection and evaluation for the masts.

Photonic masts function similarly to periscopes, but use digital equipment to support imaging rather than a mechanical, line-of-sight viewing system. Unlike a periscope, photonic masts do not need to be placed directly above the user.

Work on the contract will be performed in Northampton, Mass., and is expected to be completed by January 2019.