For immediate release: August 21, 2007

MDA Launches Electronic Information Exchange For Energy Performance Certificates In UK

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, announced today that its UK subsidiary Xit2 has launched an electronic information exchange to assist Home Information Pack (HIP) providers in procuring Energy Performance Certificates (EPCs) from Domestic Energy Assessors (DEAs).

EPCs are a compulsory element of the HIP, which came into effect in England and Wales on August 1, 2007. An EPC advises a homebuyer of the current energy efficiency of their target home and of the potential energy conservation measures that can reduce carbon emissions from this home and improve its energy efficiency.

MDA's EPC Exchange is an adaptation of MDA's valuation exchange, which connects lenders across the UK with surveyor panel managers and their panel of chartered surveyors. The EPC Exchange enables HIP providers to interact with DEAs throughout the EPC order allocation and fulfilment process, and it assists DEAs with carrying out their EPC production task, all through a convenient web based information solution.

As previously announced, MDA's EPC technology has already been adopted by SAVA Ltd, the largest training and certification centre for DEAs, and by the Royal Institute of Chartered Surveyors, to support their member certification and EPC production process. To date over 1,830 qualified Domestic Energy Assessors have pre-registered to use MDA's EPC Exchange system.

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