Sec Form 4 Filing - Chaplin Scott David @ ORBITAL ATK, INC. - 2015-02-09

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Chaplin Scott David 2. Issuer Name and Ticker or Trading Symbol ORBITAL ATK, INC. [ OA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Fmr. SVP, Gen. Counsel & Secy (Last) (First) (Middle) C/O ORBITAL ATK, INC., 45101 WARP DRIVE 3. Date of Earliest Transaction (MM/DD/YY) 02/09/2015 (Street) DULLES, VA20166 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/09/2015 F( 1 ) 933 D $ 65.25 4,426 ( 2 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Restricted Stock Units ( 3 ) 02/09/2015 A( 4 ) 2,858 03/31/2015 03/31/2015 Common Stock 2,858 $ 0 2,858 D Restricted Stock Units ( 3 ) 02/09/2015 A( 4 ) 3,192 03/31/2016 03/31/2016 Common Stock 3,192 $ 0 3,192 D Restricted Stock Units ( 3 ) 02/09/2015 A( 4 ) 1,968 03/31/2017 03/31/2017 Common Stock 1,968 $ 0 1,968 D Employee Stock Option (right to buy) $ 24.02 ( 5 ) ( 6 ) 10/01/2022 Common Stock 3,759 ( 5 ) 3,759 D Employee Stock Option (right to buy) $ 30.4041 ( 7 ) ( 8 ) 03/05/2023 Common Stock 7,271 ( 7 ) 7,271 D Employee Stock Option (right to buy) $ 61.6541 ( 9 ) ( 10 ) 03/11/2024 Common Stock 2,902 ( 9 ) 2,902 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Chaplin Scott David C/O ORBITAL ATK, INC. 45101 WARP DRIVE DULLES, VA20166 Fmr. SVP, Gen. Counsel & Secy Signatures /s/Scott D. Chaplin 02/19/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Shares withheld to pay taxes for vesting of restricted stock in connection with spin-off (Spin-off) of Vista Outdoor Inc. from Alliant Techsystems Inc. (ATK) and pursuant to terms of Transaction Agreement relating to Spin-off. ( 2 )1,180 of these shares are subject to restrictions including possible forfeiture under ATK's 2005 Stock Incentive Plan. ( 3 )1-for-1. ( 4 )In connection with Spin-off, and pursuant to terms of Transaction Agreement, Performance Awards under ATK's 2005 Stock Incentive Plan, which would have been payable following three-year performance period ending on vesting date and based upon achievement of certain performance levels, converted to time-vested Restricted Stock Units. ( 5 )This option was previously reported as an option for 3,759 shares of common stock at an exercise price of $51.96 per share but was adjusted as a result of the Spin-off. ( 6 )Three annual installments beginning 10/1/13. ( 7 )This option was previously reported as an option for 7,271 shares of common stock at an exercise price of $65.77 per share but was adjusted as a result of the Spin-off. ( 8 )Three annual installments beginning 3/5/14. ( 9 )This option was previously reported as an option for 2,902 shares of common stock at an exercise price of $133.37 per share but was adjusted as a result of the Spin-off. ( 10 )Three annual installments beginning 3/11/15.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.