For Immediate Release: March 28, 2007

MDA Books Contract Amendment To Support Commissioning Preparations For Service Manipulator On The International Space Station

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, announced today that it has signed a contract amendment valued at CAD $8.7 million with the Canadian Space Agency (CSA) to support ongoing operations of the Mobile Servicing System and upcoming pre-launch activities preparing Dextre for operation aboard the International Space Station.

Scheduled for launch later this year, MDA is preparing final procedures for deployment and initial activation of Dextre once it arrives in space. Dextre, a versatile, high precision two-armed dexterous manipulator, is part of the Mobile Servicing System, Canada's contribution to the International Space Station. The Mobile Servicing System, including Canadarm2 and Dextre are built and supported by MDA under contract to CSA. Dextre will play a central role in the maintenance of the International Space Station over the coming years.

Paul Cooper, general manager of MDA's Brampton Operations, said: "The additional CSA funding for Dextre will allow MDA to deliver optimal pre-launch support. We're proud to play an ongoing role in the mission and are very pleased that our systems provide the dependability and versatility required to support Space Station operations."

About MDA

MDA provides advanced information solutions that capture and process vast amounts of data, produce essential information, and improve the decision making and operational performance of business and government organizations worldwide.

Focused on markets and customers with strong repeat business potential, MDA delivers a broad spectrum of earth and space based information solutions, ranging from complex operational systems, to tailored information services, to electronic information products.

MDA employs more than 3,000 people in locations across the United States, the United Kingdom, and Canada. The Company's common shares trade on the Toronto Stock Exchange under the symbol TSX:MDA.