<SUBMISSION>
<ACCESSION-NUMBER>0000919574-10-006006
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20101021
<FILING-DATE>20101025
<DATE-OF-FILING-DATE-CHANGE>20101025
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>CONWAY RICHARD F
<CIK>0001299904
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-34595
<FILM-NUMBER>101140626
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>C/O LAMPE, CONWAY & CO. LLC
<STREET2>680 FIFTH AVENUE, SUITE 1202
<CITY>NEW YORK
<STATE>NY
<ZIP>10019
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ATS CORP
<CIK>0001325460
<ASSIGNED-SIC>8742
<IRS-NUMBER>113747950
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>7925 JONES BRANCH DRIVE
<CITY>MCLEAN
<STATE>VA
<ZIP>22102
<PHONE>571-766-2400
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>7925 JONES BRANCH DRIVE
<CITY>MCLEAN
<STATE>VA
<ZIP>22102
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>Federal Services Acquisition CORP
<DATE-CHANGED>20050429
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>LAMPE STEVEN
<CIK>0001260818
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-34595
<FILM-NUMBER>101140627
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>C/O LAMPE, CONWAY & CO. LLC
<STREET2>680 FIFTH AVENUE, SUITE 1202
<CITY>NEW YORK
<STATE>NY
<ZIP>10019
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>LAMPE, CONWAY & CO. LLC
<CIK>0001299982
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-34595
<FILM-NUMBER>101140628
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>680 FIFTH AVENUE, SUITE 1202
<CITY>NEW YORK
<STATE>NY
<ZIP>10019
<PHONE>2125818989
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>680 FIFTH AVENUE, SUITE 1202
<CITY>NEW YORK
<STATE>NY
<ZIP>10019
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>LC Capital Advisors LLC
<CIK>0001375479
<STATE-OF-INCORPORATION>DE
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-34595
<FILM-NUMBER>101140629
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O LAMPE, CONWAY & CO., LLC
<STREET2>680 FIFTH AVENUE, SUITE 1202
<CITY>NEW YORK
<STATE>NY
<ZIP>10019
<PHONE>(212) 581-8989
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O LAMPE, CONWAY & CO., LLC
<STREET2>680 FIFTH AVENUE, SUITE 1202
<CITY>NEW YORK
<STATE>NY
<ZIP>10019
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>p1141402.xml
<DESCRIPTION>LC CAPITAL MASTER FUND, LTD./ATS CORPORATION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-10-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001325460</issuerCik>
        <issuerName>ATS CORP</issuerName>
        <issuerTradingSymbol>ATSC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001375479</rptOwnerCik>
            <rptOwnerName>LC Capital Advisors LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TRIDENT FUND SERVICES (BVI) LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 146, WATERFRONT DRIVE</rptOwnerStreet2>
            <rptOwnerCity>ROAD TOWN TORTOLA</rptOwnerCity>
            <rptOwnerState>D8</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>VIRGIN ISLANDS, BRITISH</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001299982</rptOwnerCik>
            <rptOwnerName>LAMPE, CONWAY &amp; CO. LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>680 FIFTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>12TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001260818</rptOwnerCik>
            <rptOwnerName>LAMPE STEVEN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>680 FIFTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>12TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001299904</rptOwnerCik>
            <rptOwnerName>CONWAY RICHARD F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>680 FIFTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>12TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.81</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4402324</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4733324</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-22</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4405324</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-22</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4736324</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities are owned by LC Capital Master Fund, Ltd., which is a Reporting Person.</footnote>
        <footnote id="F2">These securities may be deemed to be beneficially owned by Lampe, Conway &amp; Co., LLC, the investment manager of LC Capital Master Fund, Ltd. and LC Capital / Capital Z SPV, L.P., Steven G. Lampe, a managing member of Lampe, Conway &amp; Co., LLC and Richard F. Conway, a managing member of Lampe, Conway &amp; Co., LLC. Each such Reporting Person disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>LC Capital Master Fund, Ltd., By: /s/ Richard F. Conway</signatureName>
        <signatureDate>2010-10-25</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Lampe, Conway &amp; Co., LLC, By: /s/ Richard F. Conway</signatureName>
        <signatureDate>2010-10-25</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Steven Lampe</signatureName>
        <signatureDate>2010-10-25</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Richard F. Conway</signatureName>
        <signatureDate>2010-10-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
