For immediate release: July 25, 2005

MDA to Develop Information Solution for Mars Exploration Mission

Richmond, B.C. - MacDONALD, DETTWILER AND ASSOCIATES LTD. (TSX:MDA ), a provider of essential information solutions, announced today that it is providing the initial study for an information solution to the Canadian Space Agency for use in NASA's 2009 Mars Science Laboratory mission. The solution will allow geologists to determine the composition of Mars' rocks and soil. This information is critical to supporting NASA's search for life and the preparation for further human planetary exploration under its Vision for Space Exploration. The CSA has awarded a $1.2 million contract to MDA for the Phase A of this solution.

MDA's information gathering solution will provide scientists with information on water activity, the formation of the planet's crust, and how the surface has been impacted by weather. The total value of the project when completed will be approximately $7.5 million.

MDA is also involved in providing atmospheric information on Mars for NASA's 2007 Mars Mission Phoenix. By further building its capacity in the deep space and space exploration markets, MDA is strengthening its position as one of the leaders in autonomous space exploration.

About MacDONALD, DETTWILER AND ASSOCIATES LTD. (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 2,500 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
www.space.gc.ca