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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Up6dTrt9N8lDekmI2sAg16YbOs7ec3Qf+xoZEnjcSMtKHRpWQtAXoS8VaVb/8VtC
 LRu4L0L35XyREZMM9hW8GQ==

<SEC-DOCUMENT>0001333014-05-000001.txt : 20050726
<SEC-HEADER>0001333014-05-000001.hdr.sgml : 20050726
<ACCEPTANCE-DATETIME>20050726163452
ACCESSION NUMBER:		0001333014-05-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050608
FILED AS OF DATE:		20050726
DATE AS OF CHANGE:		20050726

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SKYTERRA COMMUNICATIONS INC
		CENTRAL INDEX KEY:			0000756502
		STANDARD INDUSTRIAL CLASSIFICATION:	COMMUNICATION SERVICES, NEC [4899]
		IRS NUMBER:				232368845
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		19 WEST 44TH STREET
		STREET 2:		SUITE 507
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		212-730-7540

	MAIL ADDRESS:	
		STREET 1:		19 WEST 44TH STREET
		STREET 2:		SUITE 507
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RARE MEDIUM GROUP INC
		DATE OF NAME CHANGE:	19990414

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ICC TECHNOLOGIES INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INTERNATIONAL COGENERATION CORP
		DATE OF NAME CHANGE:	19891005

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Killeen Jeffrey M
		CENTRAL INDEX KEY:			0001333014

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-13865
		FILM NUMBER:		05974591

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		2127307540

	MAIL ADDRESS:	
		STREET 1:		C/O SKYTERRA COMMUNICATIONS, INC.
		STREET 2:		19 WEST 44TH STREET, SUITE 507
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-06-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000756502</issuerCik>
        <issuerName>SKYTERRA COMMUNICATIONS INC</issuerName>
        <issuerTradingSymbol>SKYT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001333014</rptOwnerCik>
            <rptOwnerName>Killeen Jeffrey M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SKYTERRA COMMUNICATIONS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>19 WEST 44TH STREET, SUITE 507</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option to Purchase</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>29.45</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-06-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-06-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>42500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option is exercisable as to one-third of the underlying shares on each of 10/28/05, 10/28/06 and 10/28/07, and acceleration upon Mr. Killeen ceasing to be renominated to an additional term of the Board of Directors.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Jeffrey M. Killeen</signatureName>
        <signatureDate>2005-07-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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