MDA to provide advanced technology solution for Internet services

For immediate release: May 10, 2010

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, announced today that it has signed a contract in excess of $10 million (USD) with Orbital Sciences Corporation (OSC) to provide an advanced technology solution. The solution will be integrated into the HYLAS 2 satellite being built for Avanti Communications Group Plc.

HYLAS 2 is a communications satellite planned for launch in 2012 that will provide significant additional capacity for Internet services in Europe, the Middle East and Africa.

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 information solutions, ranging from complex operational systems, to tailored information services, to electronic information products.

The Company's common shares trade on the Toronto Stock Exchange under the symbol TSX:MDA.

Related Websites:
www.mdacorporation.com
www.orbital.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. The forward-looking statements in this regard include statements regarding the award of a contract. Any such forward-looking statements are based on MDA’s current expectations, estimates, projections and assumptions in light of its experience and its perception of historical trends. 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. The factors and assumptions underlying the forward-looking statements in this release include contracts not being terminated. Any such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from current expectations. MDA cautions readers that should certain risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary significantly from those expected. The risks that could cause actual results to differ from current expectations include failure of third parties and subcontractors; failure of systems to meet performance requirements; changes in government priorities, funding levels, contracts and regulations; satellite failure; and failure to anticipate changes in technology, technical standards and product offerings or comply with the requisite standards.

For additional information with respect to certain of these risks or factors, plus additional risks or factors, reference should be made to MDA’s continuous disclosure materials filed from time to time with Canadian securities regulatory authorities, which are available online at www.sedar.com or on MDA’s website at www.mdacorporation.com.

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