Filed by MacDonald, Dettwiler and Associates Ltd.

Pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12

of the Securities Exchange Act of 1934

Subject Company: DigitalGlobe, Inc.

Commission File No.: 001-34299

February 24, 2017

Dear [NAME],

I am writing you today to share some important news about MacDonald, Dettwiler and Associates Ltd. (“MDA”). This morning we announced that SSL MDA Holdings Inc., the U.S. operating company of MDA, will acquire DigitalGlobe, creating an industry leader in end-to-end space and imaging systems. DigitalGlobe will operate as a subsidiary of SSL MDA Holdings, along with our SSL satellite business and the other MDA businesses in North America.

DigitalGlobe, headquartered in Colorado, is the leading provider of commercial high-resolution Earth observation and advanced geospatial solutions to the U.S. government, international governments and global commercial customers. SSL (formerly Space Systems Loral), headquartered in California, is the recognized global leader in commercial communications satellite design and manufacturing with over 85 satellites currently operating in geosynchronous orbit.

The space environment has never been more important to U.S. national security and the economic stability of the country. By combining SSL, MDA and DigitalGlobe, we are creating a full suite of vertically integrated solutions that will provide the enhanced value and capabilities that the U.S. Government requires. The combination of SSL, MDA and DigitalGlobe will have the scale, resources, and technology to serve your larger and increasingly complex needs with comprehensive, end-to-end capabilities. The combined company will substantially increase the breadth and depth of geospatial analytics and value-added services.

In 2016, SSL MDA Holdings, Inc. was formed under the guidance and approval of the U.S. Department of Defense Security Service (DSS). SSL MDA Holdings operates under a Security Control Agreement (SCA), allowing it to pursue and execute U.S. Government programs that require security clearances. The SCA facilitates the strategic combination with DigitalGlobe, which will operate as a subsidiary of SSL MDA Holdings along with SSL. Following the close of the transaction, the combined company will implement further reorganization to ensure that the ultimate parent of DigitalGlobe and SSL is incorporated in the United States by the end of 2019, subject to customary approvals. This is MDA’s third U.S. acquisition in 5 years and underscores our ongoing commitment to investment in both the U.S. and international markets. On a post-merger basis, MDA will have approximately 4,600 employees in the United States.

The transaction is expected to close in the second half of 2017 subject to customary closing conditions, including required regulatory approvals, as well as approval by both MDA and DigitalGlobe shareholders. MDA and DigitalGlobe will continue to operate separately until that time.

We are truly excited about this combination and the prospects it holds for today and the future. I invite you to read more in the attached press release, and thank you for your support.

/s/ Howard L. Lance

MacDonald, Dettwiler and Associates Ltd. (MDA) – 1570 – 200 Burrard Street, Vancouver, BC, Canada, V6C 3L6

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Certain statements and other information included in this communication constitute “forward-looking information” or “forward-looking statements” (collectively, “forward-looking statements”) under applicable securities laws, including the Private Securities Litigation Reform Act of 1995. Statements including words such as “may”, “will”, “could”, “should”, “would”, “plan”, “potential”, “intend”, “anticipate”, “believe”, “estimate” or “expect” and other words, terms and phrases of similar meaning are forward-looking statements. Forward-looking statements involve estimates, expectations, projections, goals, forecasts, assumptions, risks and uncertainties. Such forward-looking statements include, but are not limited to, statements as to MDA’s and DigitalGlobe’s managements’ expectations with respect to: the benefits of the transaction, including future financial and operating results, and strategic and integration opportunities; the combined company’s plans, objectives, expectations and intentions; expectations for sales growth, synergies, earnings and performance; shareholder value; and other statements that are not historical facts. This communication also contains forward-looking statements regarding the anticipated completion of the transaction and timing thereof.

Forward-looking statements in this communication are based on certain key expectations and assumptions made by MDA and DigitalGlobe, including expectations and assumptions concerning: market and general economic conditions; growth in demand for products and services of the combined company; currency exchange and interest rates; planned synergies, capital efficiencies and cost-savings; applicable tax laws; future debt ratings; the availability and cost of labor, services and materials; and the receipt, in a timely manner, of regulatory, stock exchange, shareholder and other third party approvals in respect of the transaction. Although management of MDA and DigitalGlobe believe that the expectations and assumptions on which such forward-looking statements are based are reasonable, undue reliance should not be placed on the forward-looking statements because MDA and DigitalGlobe can give no assurance that they will prove to be correct.

Forward-looking statements are subject to various risks and uncertainties which could cause actual results and experience to differ materially from the anticipated results or expectations expressed in this communication. Some of the key risks and uncertainties include, but are not limited to: changes in government priorities, mandates, policies, funding levels, contracts and regulations, including the grant and maintenance of security clearances, loss or reduction in scope of any of our primary contracts, or decisions by customers not to exercise renewal options; growth in the businesses of our customers and the ability of our customers to develop new services; inherent risks of performance on firm fixed price construction contracts and termination of contracts by customers for convenience; decrease in demand for our products and services; failure to maintain technological advances and offer new products to retain customers and market position; reliance on a limited number of vendors to provide certain key products or services to us; breach of our system security measures or loss of our secure facility clearance and accreditation; the loss or damage to any of our satellites; delays in the construction and launch of any of our satellites or our ability to achieve and maintain full operational capacity of all our satellites; potential for product liability or the occurrence of defects in products or systems and resulting loss of revenue and harm to our reputation; detrimental reliance on third parties for data; interruption or failure of our ground systems and other infrastructure; increased competition that may reduce our market share or cause us to lower our prices; changes in political or economic conditions, including fluctuations in the value of foreign currencies, interest rates, energy and commodity prices, trade laws and the effects of governmental initiatives to manage economic conditions; our ability to recruit, hire or retain key employees or a highly skilled and diverse workforce; potential for work stoppages; failure to obtain or maintain required regulatory approvals and licenses; failure to comply with environmental regulations; and changes in U.S., Canadian or foreign law or regulation that may limit our ability to distribute our products and services. There are also risks that are inherent in the nature of the transaction, including: failure to realize anticipated synergies or cost savings; risks regarding the integration of the two companies; and failure to obtain any required regulatory and other approvals (or to do so in a timely manner). The anticipated timeline for completion of the transaction may change for a number of reasons, including the inability to secure necessary regulatory, stock exchange or other approvals in the time assumed or the need for additional time to satisfy the conditions to the completion of the transaction. As a result of the foregoing, readers should not place undue reliance on the forward-looking statements contained in this communication concerning the timing of the transaction. Additional information concerning these and other risk factors can be found in MDA’s filings with Canadian securities regulatory authorities, which are available online under MDA’s profile at www.sedar.com or on MDA’s website at www.mdacorporation.com, and in DigitalGlobe’s filings with the United States Securities and Exchange Commission, including Item 1A of DigitalGlobe’s Annual Report on Form 10-K for the year ended December 31, 2015.

The forward-looking statements contained in this communication are expressly qualified in their entirety by the foregoing cautionary statements. All such forward-looking statements are based upon data available as of the date of this release or other specified date and speak only as of such date. MDA and DigitalGlobe disclaim any intention or obligation to update or revise any forward-looking statements in this communication as a result of new information or future events, except as may be required under applicable securities legislation.

Additional Information About the Merger and Where to Find It

This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. This communication may be deemed to be solicitation material in respect of the proposed merger of DigitalGlobe, Inc. (“DigitalGlobe”) with a wholly owned subsidiary of Macdonald, Dettwiler and Associates Ltd. (“MDA”). In connection with the proposed merger, MDA intends to file a registration statement on Form F-4 with the U.S. Securities and Exchange Commission (“SEC”), which will include a preliminary proxy statement of DigitalGlobe that also constitutes a preliminary prospectus of MDA. After the registration statement is declared effective, MDA and DigitalGlobe will mail the definitive proxy statement/prospectus to DigitalGlobe’s stockholders. The definitive proxy statement/prospectus will contain important information about the proposed merger and related matters. STOCKHOLDERS OF DIGITALGLOBE ARE URGED

TO READ ALL RELEVANT DOCUMENTS FILED WITH THE SEC, INCLUDING THE DEFINITIVE PROXY STATEMENT/PROSPECTUS (INCLUDING ALL AMENDMENTS AND SUPPLEMENTS), CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT DIGITALGLOBE AND THE MERGER. Stockholders will be able to obtain copies of the proxy statement/prospectus and other relevant materials (when they become available) and any other documents filed with the SEC by DigitalGlobe for no charge at the SEC’s website at www.sec.gov. Copies of the documents filed with the SEC by MDA also can be obtained free of charge on MDA’s corporate website at www.mdacorporation.com or by contacting MDA’s Investor Relations Department by telephone at (604) 331-2044 or by mail to MDA, Attention: Investor Relations Department, 1570 – 200 Burrard Street, Vancouver, BC V6C 3L6. Copies of the documents filed with the SEC by DigitalGlobe also can be obtained free of charge on DigitalGlobe’s corporate website at www.digitalglobe.com or by contacting DigitalGlobe’s Investor Relations Department by telephone at (303) 684-4000 or by mail to DigitalGlobe, Attention: Investor Relations Department, 1300 W. 120^th Ave., Westminster, CO 80234.

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 MDA’s 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 DigitalGlobe’s stockholders in respect of the proposed merger. Information concerning the ownership of DigitalGlobe’s securities by DigitalGlobe’s directors and executive officers is included in their SEC filings on Forms 3, 4, and 5, and additional information about DigitalGlobe’s directors and executive officers is also available in DigitalGlobe’s 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 MDA’s 2016 annual meeting of shareholders, which was filed with SEDAR on April 11, 2016 and which is available at 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.