Brazil is seeking to upgrade combat systems on its existing submarine fleet as part of an extensive defense optimization program.

Added to the planned upgrade is the scheduled construction of four conventional submarines and a nuclear-powered submarine that Brazil has contracted to build with French help. Armament on the planned submarines hasn't been discussed but is expected to be extensive.

The upgrades affect the Brazilian navy's four diesel-electric Tupi class submarines and one 1,550t Tikuna Class improved Tupi boat designed to patrol the coastal area and Brazil's offshore oil installations.

The Brazilian navy commissioned the SS Tupi in 1989 and the other three Tupi class submarines from 1996-99. The navy commissioned the fifth vessel, an improved Tupi class, also known as S34 Tikuna, in 2005. The submarines of both classes were designed by the HDW shipbuilding yard in Kiel, Germany.

The Tupi and Tikuna vessels are already armed and can launch Brazilian-made torpedoes as well as the BAE Systems Stingray.

The upgrades will involve the Mk48 heavyweight torpedo and extensive electronic refurbishment. Once upgraded the submarines could integrate other equipment, including Boeing's anti-ship missile the Harpoon. Extensive electronic refurbishment is planned as part of the upgrade.

Lockheed Martin said the Brazilian navy successfully tested its integrated combat system aboard the Tupi class SS Tapajo, as it detected, tracked and launched Mark 48 Mod 6AT torpedoes at targets during sea trials.

With the first combat system operational aboard SS Tapajo, the upgrade is focused on updating the three remaining Tupi class submarines and the Tikuna.

Lockheed Martin Maritime Systems and Sensors in Manassas, Va., received a $35.3 million firm-fixed-price contract for the modernization of the Brazilian navy's S30 Tupi class submarines' Integrated Combat Systems under the Foreign Military Sales Program.

Lockheed Martin is to adapt, procure, integrate, test and conduct factory acceptance of the ICS modernization effort, including sonar systems and flank arrays. Per the DSCA announcement, both the Tupi and Tikuna class submarines will be upgraded.

Work will be performed split between manufacturing plants in Manassas (60 percent); Syracuse, N.Y. (19 percent); Salt Lake City (15 percent); Oldsmar, Fla. (4 percent); and Baltimore (2 percent).

In addition to the naval upgrades Brazil is planning a multibillion-dollar air force modernization program. The fighter jet competition is at the center of an international lobby effort involving Boeing's Super Hornet, French aviation company Dassault's Rafale fighter jet and Swedish Saab's Grippen NG.