For Immediate Release: July 17, 2007

MDA Secures Role On Preparations For European Mars Rover Mission

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions,announced today that it has been awarded a contract for €1M with EADS Astrium (UK), to provide an advanced technology solution for ExoMars, the upcoming Mars mission of the European Space Agency (ESA). MDA will design a robotic chassis for the ExoMars rover, and provide a prototype solution for testing at ESA in 2008.

Dr. Paul Cooper, vice president and general manager of MDA's Brampton operations stated, "The rover is a high profile element within ESA's ExoMars mission, and this contract reaffirms the strategic relevance of our advanced technology solutions to space exploration missions around the world. This phase of the contract continues the work previously carried out by MDA on the earlier design phases of the ExoMars mission."

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.

Related Websites:
www.mdacorporation.com

Forward Looking Statement
This release contains forward-looking statements and information, which reflect the current view of MacDonald, Dettwiler and Associates Ltd. with respect to future events and financial performance. Any such forward-looking statements are subject to risks and uncertainties and MDA's actual results of operations could differ materially from historical results or current expectations. Additional information on these and other potential factors that could affect MDA's financial results are detailed in documents filed from time to time with the applicable Canadian securities regulatory authorities.

The Toronto Stock Exchange has neither approved nor disapproved the form or content of this release.