Kratos Defense & Security Solutions (KTOS) S-8 Registration of securities for employees

Exhibit 23.7

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement (Form S-8) of Kratos Defense & Security Solutions, Inc. pertaining to the Integral Systems, Inc. 2008 Stock Incentive Plan and to the Herley Industries, Inc. 2010 Stock Plan, with respect to the consolidated financial statements of Integral Systems, Inc. and subsidiaries as of September 25, 2009 and for the years ended September 25, 2009 and September 30, 2008, included in the October 11, 2011 Form 8-K/A of Kratos Defense & Security Solutions, Inc.

/s/ ERNST & YOUNG LLP

McLean, Virginia

March 7, 2012