EXHIBIT 10.5

FIRST AMENDMENT

TO

CHANGE IN CONTROL SEVERANCE AGREEMENT

This First Amendment to Change in Control Severance Agreement (“First
Amendment”) dated as of                     , 2008 is made and entered into by
and between Mercury Computer Systems, Inc., a Massachusetts corporation (the
“Company”), and [Name of Executive] (the “Executive”).

WHEREAS, the Company and the Executive are parties to a Change in Control
Severance Agreement dated as of                              (the “Severance
Agreement”); and

WHEREAS, the parties hereto desire to amend the Severance Agreement to comply
with the requirement of Section 409A of the Internal Revenue Code of 1986, as
amended; and

WHEREAS, capitalized terms used herein and not otherwise defined herein shall
have the meanings ascribed to them in the Severance Agreement.

NOW, THEREFORE, in consideration of the mutual covenants contained herein, the
Employers and the Executive agree as follows:

1. Section 6.1(A) of the Severance Agreement is hereby amended by adding the
following at the end thereof:

“Such amount shall be paid in one lump sum payment no later than 30 days
following the Date of Termination; provided, however, that if the Terminating
Event is during a Potential Change in Control Period, or after the Change in
Control but the Change in Control does not constitute a change in the ownership
or effective control of the Company, or in the ownership of a substantial
portion of the assets of the Company, within the meaning of Section 409A of the
Code, such amount shall be paid out on a salary continuation basis in equal
installments over a 12-month period beginning with the first payroll date that
occurs 30 days after the Date of Termination.”

2. The Severance Agreement is hereby amended by deleting the last sentence of
Section 6.2(A)(ii) and substituting therefor the following:

“In such event, the Total Payments shall be reduced in the following order:
(1) cash payments not subject to Section 409A of the Code; (2) cash payments
subject to Section 409A of the Code; (3) equity-based payments; and (4) non-cash
form of benefits. To the extent any payment is to be made over time (e.g., in
installments), then the payments shall be reduced in reverse chronological
order.”

3. The Severance Agreement is hereby amended by adding the following sentence at
the end of Section 6.3:

“If any such delayed cash payment is otherwise payable on an installment basis,
the first payment shall include a catch-up payment covering amounts that would
otherwise have been paid during the six-month period but for the application of
this provision, and the balance of the installments shall be payable in
accordance with their original schedule.”

4. All other provisions of the Severance Agreement shall remain in full force
and effect according to their respective terms, and nothing contained herein
shall be deemed a waiver of any right or abrogation of any obligation otherwise
existing under the Severance Agreement except to the extent specifically
provided for herein.

5. The validity, interpretation, construction and performance of this First
Amendment shall be governed by the laws of the Commonwealth of Massachusetts.

6. This First Amendment may be executed in several counterparts, each of which
shall be deemed to be an original but all of which together will constitute one
and the same instrument.

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IN WITNESS WHEREOF, the undersigned officer, on behalf of Mercury Computer
Systems, Inc., and the Executive have hereunto set their hands as an agreement
under seal, all as of the date first above written.

 

MERCURY COMPUTER SYSTEMS, INC.

By:

 

 

  Name   Title EXECUTIVE  

 

  [Name]

 

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