For immediate release: July 16, 2003

MDA to Study Satellite Ground Segment Requirements for Environmental Space Missions

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA) announced today that the company has recently begun working on a variety of programs related to the environment for space agencies in North America and Europe.

MDA is involved in a study contract for the European Space Agency's (ESA) SPECTRA mission. The mission will use a hyperspectral sensor to measure the role of vegetation in the carbon cycle for global and local climate change studies.

MDA is also working with various European consortia on ESA studies for two other Earth observation science missions - EarthCARE, a mission to globally measure cloud characteristics to help improve climate and weather prediction, and EPGM, a mission to provide regular global precipitation measurements.

MDA is under contract to the Canadian Space Agency to analyze Canadian contribution for NASA's HYDROS mission. HYDROS will provide soil moisture information to help meteorologists improve weather and climate prediction.

And, MDA is working with a largely Canadian consortium on the Global Monitoring for the Environment and Security (GMES) program for ESA. MDA's role involves analyzing existing infrastructure and identifying future systems and satellite missions to support applications such as monitoring for illegal oil dumping, and charting ice for marine safety.

The involvement of MDA's Information Systems group in these Study Phase contracts puts the company in a position to win further work on these programs.

Related Websites:
www.mdacorporation.com
www.nasa.gov
www.space.gc.ca
www.esa.int



For more information, please contact:

Ted Schellenberg
Media Relations
MacDonald Dettwiler
Telephone: (604) 231-2215
E-mail: teds@mda.ca