UNITED STATES


SECURITIES AND EXCHANGE COMMISSION


WASHINGTON, D.C.  20549


__________


FORM 10-K




FOR ANNUAL AND TRANSITION REPORTS


PURSUANT TO SECTIONS 13 OR 15(d) OF THE


SECURITIES EXCHANGE ACT OF 1934







(Mark One)


[X]           ANNUAL REPORT PURSUANT TO SECTION 13 or 15(d) OF THE SECURITIES


EXCHANGE ACT OF 1934




For the fiscal year ended December 31, 2011




OR




[  ]           TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES


EXCHANGE ACT OF 1934




For the transition period from __________ to __________




Commission File Numbers333-101155, 001-32424







MS STRUCTURED ASSET CORP.


Onbehalf of


SATURNS Trust No. 2005-2




(Exact name of registrant as specified in its charter)


Delaware
13-4026700(State or other jurisdiction of incorporation or organization)
(IRS Employer Identification No.)1585 Broadway, Second FloorNew York, New York
10036Attention: In-Young Chase(Address of principal executive office)
(Zip Code)Registrant’s telephone number, including area code:
(212) 761-2457


Securities registered pursuant to Section 12(b) of the Act:




Title of Each Class
Name of Each Exchange on Which RegisteredSATURNS Aon Capital Security Backed Series 2005-2 Class A Callable Units
New York Stock Exchange


Securities registered pursuant to Section 12(g) of the Act:




None







Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ___ No X





Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. Yes ___ No X




Indicate by check mark whether registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.  Yes X  No




Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ___ No ___




Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  [    ]




Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer.  See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act.  (Check one):




Large accelerated filer ___    Accelerated filer ___   Non-accelerated filer X   Smaller reporting company ___


Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).


Yes ___ NoX




All of the common stock of the registrant is held by Morgan Stanley.  As of March 26, 2012, 1,000 shares of common stock, par value $1.00 per share, were outstanding.




DOCUMENTS INCORPORATED BY REFERENCE:




The distribution reports to security holders filed on Form 8-K during the Fiscal Year in lieu of reports on Form 10-Q.




Introductory Note





The Registrant is the depositor under the trust agreements for its various SATURNS Units listed on the New York Stock Exchange.  The Units do not represent obligations of or interests in the Depositor. Pursuant to staff administrative positions established in various no-action letters, see e.g. Corporate Asset Backed Corporation (available August 9, 1995), the Registrant is not required to respond to various items of Form 10-K. Such items are designated herein as “Not applicable.”  Distribution reports detailing receipts and distributions by each trust are filed shortly after each distribution date on Form 8-K in lieu of reports on Form 10-Q.




The underlying security issuer or guarantor, as applicable, of the securities held by each of the trusts is subject to the informational requirements of the Exchange Act.  The underlying security issuer or guarantor, as applicable, currently files reports, proxy statements and other information with the SEC.  For information regarding such underlying security issuer or guarantor, you should refer to such reports.  These periodic, current and other reports and other information can be inspected and copied at the public reference facilities maintained by the SEC at Room 1024, 100 F Street, N.E., Washington, D.C. 20549. Copies of those materials can be obtained by making a written request to the SEC, Public Reference Section, 100 F Street, N.E., Washington, D.C. 20549, at prescribed rates. The SEC also maintains a website on the internet at http://www.sec.gov at which users can view and download copies of reports, proxy, information statements and other information filed electronically.  In addition, those reports and other information may also be obtained from the underlying security issuer by making a request to the underlying security issuer.  The trust, the trustee, the Registrant, and their affiliates have not verified, have not undertaken to verify, and will not verify, the content of any such reports or information. The name and the central index key (CIK) for each underlying security issuer or guarantor is set forth below:




Trust
Underlying Security Issuer or Guarantor
CIK2005-2
Aon Corporation
0000315293








PART I





ITEM 1.  BUSINESS





Not Applicable





ITEM 1A.  RISK FACTORS





Not Applicable





ITEM 1B.  UNRESOLVED STAFF COMMENTS





None





ITEM 2.  PROPERTIES





Not Applicable





ITEM 3.  LEGAL PROCEEDINGS





None





ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS





None





PART II





ITEM 5.  MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER MATTERS





The Units issued by the SATURNS trusts listed below representing investors’ interest in such trust are represented by one or more physical certificates registered in the name of Cede & Co., the nominee of The Depository Trust Company.    The Units are listed on the New York Stock Exchange:








SATURNS Trust No. 2005-2 Class A Units (Aon Capital Security Backed)





ITEM 6.  SELECTED FINANCIAL DATA





Not Applicable





ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS





Not Applicable





ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK





Not Applicable








ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA





Not Applicable





ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE





None





ITEM 9A. CONTROLS AND PROCEDURES





Not Applicable





ITEM 9B.  OTHER INFORMATION





None





PART III





ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT





None





ITEM 11. EXECUTIVE COMPENSATION





Not Applicable





ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT





None





ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS





None





ITEM 14. PRINCIPAL ACCOUNTING FEES AND SERVICES





Not Applicable








PART IV





ITEM 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K





(a) The following documents are filed as part of this Report: None





(b) Reports on Form 8-K:





See Table Below:





SATURNS

Trust No.:
Closing Date
Payment Dates
Form 8-K Filing Dates (Not Trust Agreement Filings in connection with Closing Date)

For FY 20112005-2
1/27/05
January 3 and July 1
January 5, 2011 and July 8, 2011





SATURNS

Trust No.:
Closing Date
Event Description
Form 8-K/A Filing Dates (Not Trust Agreement Filings in connection with Closing Date or filings related to Payment Dates)

For FY 20112005-2
1/27/05
A report on Form 8-K/A amending and superseding Exhibit 99.1 to the Distribution Reports filed during the period from July 12, 2005 through January 5, 2011.
September 1, 2011





(c) Exhibits: 
 Exhibit 23
Consent of Pustorino, Puglisi & Co., LLP (See Exhibit 99.1 – contained in final paragraph of accountants’ letter)
 Exhibit 31.1
Rule 13a-14(d) Certification
 Exhibit 31.2
Trustee Compliance Certification (Bank of America, National Association)
 Exhibit 31.3
Trustee Compliance Certification (U.S. Bank National Association)
 Exhibit 99.1
Report of Pustorino, Puglisi & Co., LLP
 
 (d) Not applicable










SIGNATURES




Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.









Date:  March 29, 2012






MS STRUCTURED ASSET CORP.(Registrant)By: /s/In-Young ChaseName:        In-Young ChaseTitle:          Vice President