General Dynamics is a defense contractor and business jet manufacturer. The firm's segments include aerospace, marine, combat systems, and technology. General Dynamics' aerospace segment manufactures Gulfstream business jets and operates aglobal aircraft servicing operation. Combat systems produces land-based combat vehicles such as the M1 Abrams tank and Stryker armored personnel carrier, as well as munitions. The marine segment builds and services nuclear-powered submarines, destroyers, and other ships. The technologies segment contains two main units: an IT business that primarily serves the government market and a mission systems business that focuses on products that provide command, control, computing, intelligence, surveillance, and reconnaissance capabilities to the military.