UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                                 WASHINGTON, DC  20549
    
                               SCHEDULE 13G
    
                        UNDER THE SECURITIES EXCHANGE ACT OF 1934
    
                                (AMENDMENT NO.     )*
    
                        MERCURY COMPUTER SYSTEMS INC     
    ________________________________________________________________________
                                        (Name of Issuer)
    
                                    Common
    ________________________________________________________________________
                               (Title of Class of Securities)
    
                               589378108
                      _______________________________
                                     (CUSIP Number)
    
    
    Check the following box if a fee is being paid with this statement 
    [   ].  (A fee is not required only if the filing person:  (1) has a
    previous statement on file reporting beneficial ownership of more
    than five percent of the class of securities described in Item 1;
    and (2) has filed no amendment subsequent thereto reporting
    beneficial ownership of five percent or less of such class.)  (See
    Rule 13d-7.)
    
    *The remainder of this cover page shall be filled out for a 
    reporting person's initial filing on this form with respect to the 
    subject class of securities, and for any subsequent amendment
    containing information which would alter the disclosures provided
    in a prior cover page.
    
    The information required in the remainder of this cover page shall
    not be deemed to be filed for the purpose of Section 18 of the
    Securities Exchange Act of 1934 ("Act") or otherwise subject to
    the liabilities  of that section of the Act but shall be subject to
    all other provisions of the Act (however, see the Notes).
    
                                        Page 1 of 2 pages
    
    CUSIP No.  589378108
                                  13G
    ________________________________________________________________________
    1        NAME OF REPORTING PERSON
             S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
             Massachusetts Mutual Life Insurance Company
             04-1590850
    ________________________________________________________________________
    2        CHECK THE APPROPRIATE BOX IF MEMBER OF A GROUP
                                        (A)  _______
    
                                        (B)  __x____
    ________________________________________________________________________
    3        SEC USE ONLY
    
    
    
    ________________________________________________________________________
    4        CITIZENSHIP OF PLACE OF ORGANIZATION
    
             Commonwealth of Massachusetts
    ________________________________________________________________________
                      5        SOLE VOTING POWER
    NUMBER OF
       SHARES                   500,000
                      ____________________________________________________
    BENEFICIALLY      6        SHARED VOTING POWER
       OWNED BY
       EACH                    not applicable
                      ____________________________________________________
    REPORTING         7        SOLE DISPOSITIVE POWER
       PERSON
       WITH                     500,000
                      ____________________________________________________
                      8        SHARED DISPOSITIVE POWER
    
                               not applicable
    ________________________________________________________________________
    9        AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
             PERSON
    
             500,000
    ________________________________________________________________________
    10       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES
             CERTAIN SHARES *
    
             not applicable
    ________________________________________________________________________
    11       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
    
                  5.05%
    ________________________________________________________________________
    12       TYPE OF REPORTING PERSON *
    
             IC  (insurance company)
    ________________________________________________________________________
    
                      *  SEE INSTRUCTION BEFORE FILLING OUT!
    
                                        Page 2 of 2 pages
    
    CUSIP No.  589378108
                                  13G
    ________________________________________________________________________
    1        NAME OF REPORTING PERSON
             S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
             MassMutual Corporate Investors
             04-2483041
    ________________________________________________________________________
    2        CHECK THE APPROPRIATE BOX IF MEMBER OF A GROUP
                                        (A)  _______
    
                                        (B)  __x____
    ________________________________________________________________________
    3        SEC USE ONLY
    
    
    
    ________________________________________________________________________
    4        CITIZENSHIP OF PLACE OF ORGANIZATION
    
             Commonwealth of Massachusetts
    ________________________________________________________________________
                      5        SOLE VOTING POWER
    NUMBER OF
       SHARES                  500,000
                      ____________________________________________________
    BENEFICIALLY      6        SHARED VOTING POWER
       OWNED BY
       EACH                    not applicable
                      ____________________________________________________
    REPORTING         7        SOLE DISPOSITIVE POWER
       PERSON
       WITH                    500,000
                      ____________________________________________________
                      8        SHARED DISPOSITIVE POWER
    
                               not applicable
    ________________________________________________________________________
    9        AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
             PERSON
    
             500,000
    ________________________________________________________________________
    10       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES
             CERTAIN SHARES *
    
             not applicable
    ________________________________________________________________________
    11       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
    
                 5.05%
    ________________________________________________________________________
    12       TYPE OF REPORTING PERSON *
    
             IV (investment company)
    ________________________________________________________________________
    
                      *  SEE INSTRUCTION BEFORE FILLING OUT!
    
    
    ITEM 1(a).  Name of Issuer:  Mercury Computer Systems, Inc.
    
    ITEM 1(b).  Address of Issuer's Principal Executive Offices:
    
                199 Riverneck Road
                Chelmsford, MA  01824    
    
    ITEM 2(a).  Name of Person Filing:
    
                This statement is filed on behalf of Massachusetts
                Mutual Life Insurance Company and MassMutual 
                Corporate Investors, which together may be
                regarded as a group for the purpose of this 
                statement.  This statement is signed on behalf
                of both the aforementioned parties, and therefore
                it does not include a separate agreement
                providing for a joint filing.
    
    ITEM 2(b).  Address of Principal Business Office:
    
                MASSACHUSETTS MUTUAL LIFE INSURANCE COMPANY
                1295 State Street
                Springfield, Massachusetts  01111
    
                MASSMUTUAL CORPORATE INVESTORS
                1295 State Street
                Springfield, Massachusetts  01111
    
    ITEM 2(c).  Citizenship
    
                MASSACHUSETTS MUTUAL LIFE INSURANCE COMPANY is
                organized under the laws of the Commonwealth of Massachusett
    
                MASSMUTUAL CORPORATE INVESTORS is
                organized under the laws of the Commonwealth of Massachusett
    
    ITEM 2(d).  Title of Class of Securities:  Common Stock
    
    ITEM 2(e).  CUSIP NUMBER:  589378108
    
    ITEM 3.     This statement is filed pursuant to Rule 13d-1(b) by
                Massachusetts Mutual Life Insurance Company,
                an insurance company as defined  in Section 3(a)(19), and
                MassMutual Corporate Investors, an investment
                company registered under Section 8 of the Investment
                Company Act of 1940, which together may be
                regarded as a group pursuant to  Rule
                13d-1(b) (ii) (H).
    
    ITEM 4.     Ownership:
    
                This statement if filed to report information as of
                January 29, 1998.
    
                (a)  Amount Beneficially Owned:
    
                Massachusetts Mutual Life Insurance Company,
                and MassMutual Corporate Investors each own
                500,000 shares of common stock.
    
                Total shares of common stock owned directly and
                indirectly:  1,000,000.
    
                The filing of this statement shall not be construed 
                as an admission that Massachusetts Mutual Life
                Insurance Company and MassMutual Corporate Investors,
                Investors, are for the purposes of sections 13(d) and
                13(g) of the Securities Exchange Act of 1934, the
                beneficial owners of any common stock of the issuer.
    
                (b)  Percent of Class:
    
                Percentage of ownership is calculated as follows:
    
                1,000,000 (shs held) / 9,868,223 (shares outstanding)
                        = 10.1%
    
    
                (c)  Powers:
    
                Massachusetts Mutual Life Insurance Company and
                MassMutual Corporate Investors, each have sole power
                to vote or dispose of 500,000 shares of common stock.
    
    ITEM 5.     Ownership of Five Percent or Less of a Class:
    
                Not Applicable
    
    ITEM 6.     Ownership of More Than Five Percent on Behalf
                of Another Person:
    
                Not applicable
    
    ITEM 7.     Identification and Classification of the 
                Subsidiary Which Acquired the Security Being
                Reported on by the Parent Holding Company:
    
                Note applicable
    
    ITEM 8.     Identification and Classification of Members
                of the Group:
    
                not applicable
    
    ITEM 9.     Notice of Dissolution of the Group:
    
                Not applicable
    
    ITEM 10.    Certification:
    
                By signing below, MASSACHUSETTS MUTUAL LIFE 
                INSURANCE COMPANY and MASSMUTUAL 
                CORPORATE INVESTORS certify to the best of 
                their knowledge and belief, the securities referred to
                above were acquired in the ordinary course of 
                business and were not acquired for the purpose of
                and do not have the effect of changing or  
                influencing the control of the issuer of such 
                securities and were not acquired in connection
                with or as a participant in any transaction having
                such purpose or effect.
    
    Signature
    ---------
                After reasonable inquiry and to the best of knowledge 
                and belief, MASSACHUSETTS MUTUTAL LIFE INSURANCE
                COMPANY and MASSMUTUAL CORPORATE INVESTORS,
                INVESTORS, certify that the information set forth in this
                statement is true, complete and correct. 
    
    
    February 9, 1998                    February 9, 1998
    _____________________               _____________________
         Date                                Date
    
    MASSACHUSETTS MUTUAL                MASSMUTUAL CORPORATE
    LIFE INSURANCE COMPANY              INVESTORS
    
    By:  signature                      By:  signature
    
    
    Richard C. Morrison                 Richard C. Morrison
    Managing Director                   Vice President 
    _________________________           _________________________
    (Print Name and Title               (Print Name and Title 
     of Person Signing)                  of Person Signing)