The U.S. Air Force awarded Lockheed Martin an $81.9 million contract for an engineering effort for two next-generation missile warning satellites, the U.S. Defense Department announced Sept. 10.

The cost-plus-incentive-fee contract for the fifth and sixth Space Based Infrared System (SBIRS) satellites provides funding for updating obsolete parts, performing early stage development and procuring long-lead supplies, according to the contract announcement. The performance period for the work ends Aug. 21, 2015.

SBIRS prime contractor Lockheed Martin Space Systems of Sunnyvale, Calif., is under full production contracts for the delivery of four dedicated spacecraft for geosynchronous orbit. The program satellites are designed to join the service’s legacy Defense Support Program satellites on orbit to provide the United States with global, persistent surveillance of missile launches, as well as to contribute to other missions such as missile defense and tactical intelligence.

Peter B. de Selding was the Paris bureau chief for SpaceNews.