In addition, in connection with the proposed merger, a management information circular of MDA, describing details of the transaction and other information, will be mailed to MDAs shareholders. The management information circular will contain important information about the proposed merger and related matters. SHAREHOLDERS OF MDA ARE URGED TO READ ALL RELEVANT DOCUMENTS FILED WITH CANADIAN SECURITIES REGULATORY AUTHORITIES, INCLUDING THE MANAGEMENT INFORMATION CIRCULAR, CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT MDA AND THE MERGER. Additional information about MDA, including all relevant documents filed with Canadian securities regulatory authorities, can be found under its corporate profile on SEDAR at  www.sedar.com or by contacting the contact above.

PARTICIPANTS IN THE SOLICITATION 

This communication is not a solicitation of proxies in connection with the proposed merger. However, DigitalGlobe, MDA and their respective directors and executive officers and certain other employees may be deemed to be participants in the solicitation of proxies from DigitalGlobes stockholders in respect of the proposed merger. Information concerning the ownership of DigitalGlobes securities by DigitalGlobes directors and executive officers is included in their SEC filings on Forms 3, 4, and 5, and additional information about DigitalGlobes directors and executive officers is also available in DigitalGlobes proxy statement for its 2016 annual meeting of stockholders filed with the SEC on April 14, 2016. Information about the directors and executive officers of MDA is set forth in the Management Proxy Circular for MDAs 2016 annual meeting of shareholders, which was filed with SEDAR on April 11, 2016 and which is available at  www.sedar.com. Other information regarding persons who may be deemed participants in the proxy solicitation, including their respective interests by security holdings or otherwise, will be set forth in the proxy statement/prospectus relating to the proposed merger when it becomes available and is filed with the SEC. These documents can be obtained free of charge from the sources indicated above.

ABOUT MDA

MDA (TSX:MDA), is 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.

MacDonald, Dettwiler and Associates Ltd. (MDA) common shares trade on the Toronto Stock Exchange under the symbol " MDA."

ABOUT SSL MDA HOLDINGS

SSL MDA Holdings, Inc., based in San Francisco, CA, is a wholly owned subsidiary of MacDonald, Dettwiler and Associates Ltd. and serves as the operating company for all MDA businesses.

ABOUT DIGITALGLOBE

DigitalGlobe is a leading global provider of high-resolution Earth-imagery products and services sourced from our own advanced satellite constellation and third-party providers. Our imagery solutions support a wide variety of users in defense and intelligence, civil agencies, mapping and analysis, environmental monitoring, oil and gas exploration, infrastructure management, Internet portals, and navigation technology. Each day users depend on us to better understand our changing planet in order to save lives, resources and time.

MDA CONTACTS

Investor Relations
Marissa Poratto
MDA Investor Relations
(604) 331-2044
Email Contact

Media relations (Canada):
Wendy Keyzer
MDA Media Relations
(604) 231-2743
Email Contact

Media relations (United States):
Trevor R. Martin
Abernathy MacGregor
(415) 926-7961
Email Contact

DIGITALGLOBE CONTACTS

Investor Relations
Fred Graffam
DigitalGlobe, Inc. 
(303) 684-1692
Email Contact

Media Relations
Turner Brinton
DigitalGlobe, Inc.
(303) 684-4545
Email Contact

Eric Brielmann / Scott Bisang / Matthew Gross
Joele Frank, Wilkinson Brimmer Katcher
(212) 355-4449