The MK-99 is a component of the Aegis combat system that controls the loading and arming of selected weapons, launching of the weapon, and provides terminal guidance for AAW missiles.
The system also controls the target illumination for ship-launched SM-2 Anti-Air Missiles.
The contract also contains "Aegis modernisation production requirements and associated engineering services", and was awarded by Naval Sea Systems Command.
Aegis is an advanced maritime warfighting capability and the world’s only maritime ballistic missile defence system. Aegis is a complete multi-mission combat system and is currently successfully integrated across 107 ships, nine classes for six nations, including the US, Japan, Australia the Republic of Korea, Spain and Norway.
Aegis is being rolled out to the Royal Australian Navy, with the first capable warships, Hobart Class guided missile destroyers, paving the way for its introduction into Australia.
The combat system allows co-operative engagement capabilities between the RAN and the US Navy, with HMAS Hobart successfully testing the ability to share sensor information and real-time combat system data with other warships in November 2018.
During testing near Hawaii late last year, Hobart established secure data links with the US Arleigh Burke Class Destroyer USS John Finn and "shared tracking and fire control data across the two ships".
Australia has also announced that Aegis will be implemented into the new Hunter Class frigate fleet.