MDA announces retirement of SSL President and new Executive appointments

San Francisco and Vancouver, BC-MacDonald, Dettwiler and Associates Ltd. ("MDA" or the "Company")(TSX: MDA), a global communications and information company, today announced that John Celli will be retiring as President of SSL (Space Systems Loral) after serving the company for 36 years. Dario Zamarian has been appointed Group President and Paul Estey has been appointed Executive Vice President and Chief Operating Officer at SSL, both effective July 17, 2017. SSL is a leading provider of innovative satellites and spacecraft systems.

“I want to thank John for his many years of outstanding service at SSL, and for his role as a highly regarded leader in the satellite industry,” said Howard L. Lance, president and chief executive officer of MDA. “His passion for space technology and his commitment to both customers and employees drove SSL to a leadership position in satellite design and manufacturing and set the groundwork for future growth based on innovative thinking and technical excellence.”

Under Mr. Celli’s leadership, SSL grew and earned a reputation among customers as an innovator and leader in the satellite industry. As President of SSL, Mr. Celli earned a reputation across the industry as a forward thinker with high integrity and an uncompromising commitment to quality. In 2016 Mr. Celli received multiple honors and awards for his leadership. He was honored by the Silicon Valley Engineering Council as an entrant into its Hall of Fame, he was inducted into the Society of Satellite Professionals International (SSPI) Hall of Fame, and he received the Outstanding Service to Industry award at the World Space Risk Forum (WSRF) in Dubai.

John Celli joined SSL in 1981 when he was recruited from his home in Italy to work as an antenna engineer at the Palo Alto facility. Over the years he held increasingly responsible roles as Solar Array Supervisor, Mechanical Engineering Manager, and Director of Spacecraft. One of his proudest achievements was his role as Executive Director for the Intelsat IX program where he led the successful development and delivery of seven advanced multi-frequency communication satellites for the world’s leading satellite operator.

“It’s been an honor to serve in this industry with my SSL colleagues and customers throughout the past 36 years,” noted John Celli. “Looking ahead I am confident that SSL will continue to grow and lead the industry.”

Mr. Zamarian brings a wealth of experience in leading transformative growth and executive leadership experience to SSL, where he will work closely with the ongoing SSL senior executive team to support the needs of satellite operators around the world and drive growth into new markets. Since 2013, Mr. Zamarian has advised multiple technology companies affiliated with the Blackstone Group and served on several of their company boards. Most notably, he was instrumental in the strategy formulation, acquisition and integration activities that formed Optiv Security, a market-leading provider of end-to-end cyber security solutions.

Previously, he was Global Vice President and Worldwide General Manager, Enterprise Systems and Solutions business at Dell Technologies from 2010-2013. Mr. Zamarian served as Vice President and General Manager, Systems and Network Management business at Cisco Systems from 2004-2010. Additionally, he held positions in corporate strategy, product management, sales and software engineering for technology firms in Silicon Valley. Mr. Zamarian received his BSEE and MSEE from the Polytechnic University in Turin, Italy and an MBA from INSEAD in France.

“I’m looking forward to the opportunity to join a world-class company such as SSL,” said Dario Zamarian, “Driving growth in new markets and surpassing the needs of satellite operators around the globe is an exciting proposition and the combination of the new leadership team gives me confidence that SSL will continue to grow and lead the industry.”

Mr. Zamarian’s responsibilities as SSL Group President will include all of the satellite and space systems markets the company serves including GEO Communications, LEO Communications and Earth Observation, Space Infrastructure Services and U.S. Government Systems.

Dr. Paul Estey joined SSL in 1997. He currently serves as Executive Vice President, Engineering and Operations. Dr. Estey earned his BSME at Queens University in Kingston, Ontario, his MSME at the Massachusetts Institute of Technology, and his PhD in Engineering at Stanford University.

About MDA

MDAis a global communications and information company providing operational solutions to commercial and government organizations worldwide.

MDA's business is focused on markets and customers with strong repeat business potential, primarily in the Communications sector and the Surveillance and Intelligence sector. In addition, the Company conducts a significant amount of advanced technology development.

MDA's established global customer base is served by more than 4,800 employees operating from 15 locations in the United States, Canada, and internationally.

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

About SSL MDA Holdings

SSL MDA Holdings is a wholly owned subsidiary of MacDonald, Dettwiler and Associates Ltd. (MDA) and serves as the operating company for all MDA businesses. SSL MDA Holdings has its headquarters in San Francisco.

About SSL

Space Systems Loral (SSL) is a leading provider of commercial satellites with broad expertise to support satellite operators and innovative space related missions. The company designs and manufactures spacecraft for services such as direct-to-home television, video content distribution, broadband internet, mobile communications, and Earth observation. As a Silicon Valley innovator for 60 years, SSL’s advanced product line also includes state-of-the-art small satellites, and sophisticated robotics and automation solutions for remote operations. For more information, visitwww.sslmda.com.

Related Websites
www.mdacorporation.com
www.sslmda.com

Forward-Looking Statements
This release may contain forward-looking statements and information, which reflect the current view of MacDonald, Dettwiler and Associates Ltd. and its subsidiaries (collectively “MDA” or the “Company”) with respect future events. 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.

For additional information with respect to certain of these risks or factors, plus additional risks or factors, reference should be made to the Company's continuous disclosure materials filed from time to time with Canadian securities regulatory authorities, which are available online under the Company's profile atwww.sedar.comor on the Company's website atwww.mdacorporation.com.

The Toronto Stock Exchange has neither approved nor disapproved the form or content of this release.