For immediate release: May 31, 2007

MDA to Develop Advanced Technology Solution to Detect Airborne Biological Threats

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, announces the award of a $4 million CAD contract with Defence Research and Development Canada (DRDC) to develop an advanced technology solution that can sense, track, map and classify airborne biological threats from several kilometres away.

MDA's solution will be housed inside a special purpose vehicle and will include the sensor, a processing system and an operator workstation. The sensor used to detect biological aerosol agents will be lifted through the roof of the vehicle when operating. Final delivery of the system is expected to be in June 2009.

This contract allows MDA to further develop key capabilities that may have future application in the large U.S. Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) market.

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 Statements

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.



For more information, please contact:

Wendy Keyzer
MDA External Relations
Telephone: 604-231-2743
E-mail: wendy@mdacorporation.com