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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000938166-09-000002.txt : 20090105
<SEC-HEADER>0000938166-09-000002.hdr.sgml : 20090105
<ACCEPTANCE-DATETIME>20090105165220
ACCESSION NUMBER:		0000938166-09-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090102
FILED AS OF DATE:		20090105
DATE AS OF CHANGE:		20090105

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Little Pamela A
		CENTRAL INDEX KEY:			0001337465

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51552
		FILM NUMBER:		09506085

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		301-774-6400

	MAIL ADDRESS:	
		STREET 1:		SANDY SPRING BANK
		STREET 2:		17801 GEORGIA AVENUE
		CITY:			OLNEY
		STATE:			MD
		ZIP:			20832

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ATS CORP
		CENTRAL INDEX KEY:			0001325460
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MANAGEMENT CONSULTING SERVICES [8742]
		IRS NUMBER:				113747950
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		7925 JONES BRANCH DRIVE
		CITY:			MCLEAN
		STATE:			VA
		ZIP:			22102
		BUSINESS PHONE:		571-766-2400

	MAIL ADDRESS:	
		STREET 1:		7925 JONES BRANCH DRIVE
		CITY:			MCLEAN
		STATE:			VA
		ZIP:			22102

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Federal Services Acquisition CORP
		DATE OF NAME CHANGE:	20050429
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-01-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001325460</issuerCik>
        <issuerName>ATS CORP</issuerName>
        <issuerTradingSymbol>ATCT.OB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001337465</rptOwnerCik>
            <rptOwnerName>Little Pamela A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7925 JONES BRANCH DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MCLEAN</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP and CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-01-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>42000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>171704</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The total amount of securities includes 9,704 shares purchased in 2008 per the terms of the Company's 2007 Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">Represents 42,000 restricted shares under the terms of the Omnibus Incentive Compensation Plan, of which 14,000 shares vest on each January 2, beginning January 2, 2010.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Pamela A. Little</signatureName>
        <signatureDate>2009-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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