SC 13D/A

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934
(Amendment No. 10)*

Motient Corporation

(Name of Issuer)

Common Stock, par value $0.01 per share
(Title of Class of Securities)

619908304
(CUSIP Number)

Patrick H. Daugherty, Esq.
Highland Capital Management, L.P.
Two Galleria Tower
13455 Noel Road, Suite 1300
Dallas, Texas 75240
(972) 628-4100
(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

October 26, 2005
(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. o

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

^* 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 disclosures provided in a prior cover page.

The information required on 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).

Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

CUSIP No. 619908304					Page 2 of 17
	1.	Name of Reporting Person: Prospect Street High Income Portfolio, Inc.			I.R.S. Identification Nos. of above persons (entities only): 04-3028343
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Maryland
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 1,155,224
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 1,155,224
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 1,155,224
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 1.7%
	14.	Type of Reporting Person (See Instructions): CO/IV

CUSIP No. 619908304					Page 3 of 17
	1.	Name of Reporting Person: Prospect Street Income Shares Inc.			I.R.S. Identification Nos. of above persons (entities only): 36-2765811
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Maryland
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 111,940
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 111,940
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 111,940
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 0.2%
	14.	Type of Reporting Person (See Instructions): CO/IV

CUSIP No. 619908304					Page 4 of 17
	1.	Name of Reporting Person: Highland Legacy Limited			I.R.S. Identification Nos. of above persons (entities only):
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Cayman Islands
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 223,880
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 223,880
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 223,880
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 0.3%
	14.	Type of Reporting Person (See Instructions): OO

CUSIP No. 619908304					Page 5 of 17
	1.	Name of Reporting Person: Highland Crusader Offshore Partners, L.P.			I.R.S. Identification Nos. of above persons (entities only):
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Bermuda
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 5,352,497
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 5,352,497
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 5,352,497
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 8.1%
	14.	Type of Reporting Person (See Instructions): PN

CUSIP No. 619908304					Page 6 of 17
	1.	Name of Reporting Person: PAMCO Cayman, Limited			I.R.S. Identification Nos. of above persons (entities only):
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Cayman Islands
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 223,880
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 223,880
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 223,880
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 0.3%
	14.	Type of Reporting Person (See Instructions): OO

CUSIP No. 619908304					Page 7 of 17
	1.	Name of Reporting Person: Highland Equity Focus Fund, L.P.			I.R.S. Identification Nos. of above persons (entities only): 46-0491961
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Delaware
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 1,518,779
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 1,518,779
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 1,518,779
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 2.3%
	14.	Type of Reporting Person (See Instructions): PN

CUSIP No. 619908304					Page 8 of 17
	1.	Name of Reporting Person: Highland Select Equity Fund, L.P.			I.R.S. Identification Nos. of above persons (entities only):
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Delaware
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 119,283
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 119,283
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 119,283
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 0.2%
	14.	Type of Reporting Person (See Instructions): PN

CUSIP No. 619908304					Page 9 of 17
	1.	Name of Reporting Person: Highland Capital Management Services, Inc.			I.R.S. Identification Nos. of above persons (entities only):
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Delaware
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 182,748
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 182,748
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 182,748
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 0.3%
	14.	Type of Reporting Person (See Instructions): CO

CUSIP No. 619908304					Page 10 of 17
	1.	Name of Reporting Person: Highland Capital Management, L.P.			I.R.S. Identification Nos. of above persons (entities only): 75-2716725
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): AF/WC
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Delaware
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 8,822,764
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 8,822,764
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 8,822,764
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 13.3%
	14.	Type of Reporting Person (See Instructions): IA/PN

CUSIP No. 619908304					Page 11 of 17
	1.	Name of Reporting Person: Strand Advisors, Inc.			I.R.S. Identification Nos. of above persons (entities only): 95-4440863
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): AF
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: Delaware
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 8,822,764
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 8,822,764
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 8,822,764
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 13.3%
	14.	Type of Reporting Person (See Instructions): CO

CUSIP No. 619908304					Page 12 of 17
	1.	Name of Reporting Person: James Dondero			I.R.S. Identification Nos. of above persons (entities only):
	2.	Check the Appropriate Box if a Member of a Group (See Instructions):
		(a)	þ
		(b)	o
	3.	SEC Use Only:
	4.	Source of Funds (See Instructions): AF/PF
	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): o
	6.	Citizenship or Place of Organization: United States
Number of Shares Beneficially Owned by Each Reporting Person With
			7.	Sole Voting Power: 9,024,326
			8.	Shared Voting Power: 0
			9.	Sole Dispositive Power: 9,024,326
			10.	Shared Dispositive Power: 0
	11.	Aggregate Amount Beneficially Owned by Each Reporting Person: 9,024,326
	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): o
	13.	Percent of Class Represented by Amount in Row (11): 13.6%
	14.	Type of Reporting Person (See Instructions): IN

Page 13 of 17

     This Amendment No. 10 to Schedule 13D amends and supplements the Schedule 13D filed with the Securities and Exchange Commission (the “Commission”) on June 10, 2002, as amended by Amendment No. 1 to Schedule 13D filed with the Commission on October 20, 2003, Amendment No. 2 to Schedule 13D filed with the Commission on July 12, 2004, Amendment No. 3 to Schedule 13D filed with the Commission on November 16, 2004, Amendment No. 4 to Schedule 13D filed with the Commission on April 19, 2005, Amendment No. 5 to Schedule 13D filed with the Commission on September 7, 2005, Amendment No. 6 to Schedule 13D filed with the Commission on September 29, 2005, Amendment No. 7 to Schedule 13D filed with the Commission on October 11, 2005, Amendment No. 8 to Schedule 13D filed with the Commission on October 14, 2005 and Amendment No. 9 to Schedule 13D filed with the Commission on October 21, 2005 (as amended, the “Schedule 13D”). Capitalized terms used herein which are not defined herein have the meanings given to such terms in the Schedule 13D. Except as otherwise provided herein, all Items of the Schedule 13D remain unchanged.

Item 4. Purpose of the Transaction.

     Item 4 is hereby supplemented as follows:

     On October 26, 2005, Mr. James D. Dondero, a member of the Board of Directors (the “Board”) of Motient Corporation (the “Company”), whose principal business is serving as the President of the General Partner of Highland Capital Management, L.P. (“Highland”), sent the attached letter to the other members of the Board, addressing the amended exchange offer by the Company (the “Exchange Offer”), attached as an exhibit to the tender offer of the Company filed with the Commission on October 12, 2005, pursuant to which the Company is seeking to exchange its Series B Cumulative Convertible Preferred Stock (the “Series B Preferred”) for outstanding shares of Series A Cumulative Convertible Preferred Stock of the Company (the “Series A Preferred”). Mr. Dondero’s letter requests certain materials and raises certain issues in connection with the October 26, 2005 meeting of the Board (the “Board Meeting”), and addresses his continued concerns with respect to the Exchange Offer, which offer expired at 5:00 p.m., New York City time, on October 26, 2005. A copy of the letter from Mr. Dondero is attached hereto as Exhibit 99.2.

     On October 26, 2005, Highland, on behalf of itself and Highland Crusader Offshore Partners, L.P., Highland Equity Focus Fund, L.P. and Highland Capital Management Services, Inc. (collectively, the “Highland Parties”), sent the attached letter to the Company in order to inform the Company that the Highland Parties would not be exchanging their shares of the Series A Preferred for shares of the Series B Preferred pursuant to the Exchange Offer. A copy of the letter from Highland is attached hereto as Exhibit 99.3.

     On October 27, 2005, Mr. Dondero sent the attached letter to the other members of the Board, acknowledging the Board’s refusal to provide Mr. Dondero with requested materials prior to the Board Meeting, and stating that his attempts at discussion with the Board at the Board Meeting were ignored. A copy of the letter from Mr. Dondero is attached hereto as Exhibit 99.4.

     In response to the foregoing actions, among others, the Reporting Persons are considering various plans or proposals which relate to or could result in the transactions or changes contemplated by Items 4(a) through 4(j) of Schedule 13D. Such plans or proposals could include acquisitions of additional shares in the open market or otherwise and potentially seeking possible changes in the present Board and management of the Company. In the interim and prior to formulating any definitive plan or proposal, the Reporting Persons may communicate with other stockholders regarding their concerns about the actions taken by the Company and its management.

Page 14 of 17

Item 7. Material to be Filed as Exhibits.

     Item 7 is hereby amended and supplemented as follows:

Exhibit 99.2	Letter of James D. Dondero to the Board of Directors of Motient Corporation, dated October 25, 2005.
Exhibit 99.3	Letter of Highland Capital Management, L.P. to Motient Corporation, dated October 26, 2005.
Exhibit 99.4	Letter of James D. Dondero to the Board of Directors of Motient Corporation, dated October 26, 2005

Page 15 of 17

SIGNATURE

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: October 27, 2005

HIGHLAND CAPITAL MANAGEMENT, L.P.
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President
STRAND ADVISORS, INC.
By:	/s/ James Dondero
Name:	James Dondero
Title:	President
/s/ James Dondero
James Dondero
PROSPECT STREET HIGH INCOME PORTFOLIO, INC.
By:	/s/ James Dondero
Name:	James Dondero
Title:	President
PROSPECT STREET INCOME SHARES INC.
By:	/s/ James Dondero
Name:	James Dondero
Title:	President
HIGHLAND LEGACY LIMITED
By:	Highland Capital Management, L.P., its collateral manager
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President
HIGHLAND CRUSADER OFFSHORE PARTNERS, L.P.
By:	Highland Capital Management, L.P., its general partner
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President

Page 16 of 17

PAMCO CAYMAN, LIMITED
By:	Highland Capital Management, L.P., its collateral manager
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President
HIGHLAND EQUITY FOCUS FUND, L.P.
By:	Highland Capital Management, L.P., its general partner
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President
HIGHLAND SELECT EQUITY FUND, L.P.
By:	Highland Capital Management, L.P., its general partner
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President
HIGHLAND CAPITAL MANAGEMENT SERVICES, INC.
By:	/s/ James Dondero
Name:	James Dondero
Title:	President

Page 17 of 17

APPENDIX I

     The name of each director and officer of HCM Services, Strand, Prospect Portfolio and Prospect Shares is set forth below. Unless otherwise indicated, the business address of each person listed below is Two Galleria Tower, 13455 Noel Road, Suite 1300, Dallas, Texas 75240. Each person identified below is a citizen of the United States of America. The present principal occupation or employment of each of the listed persons is set forth below. During the past five years, none of the individuals listed below has been convicted in a criminal proceeding or been a party to a civil proceeding, in either case of the type specified in Items 2(d) or (e) of Schedule 13D.

	Present Principal Occupation or Employment
Name	and Business Address (if applicable)
Highland Capital Management Services, Inc.
James D. Dondero, Director	President
Mark K. Okada, Director	Executive Vice President
Patrick H. Daugherty	Secretary
Todd A. Travers	Assistant Secretary
J. Kevin Ciavarra	Assistant Secretary
David Lancelot	Treasurer
Chad Schramek	Treasurer
Strand Advisors, Inc.
James D. Dondero, Director	President
Mark K. Okada	Executive Vice President
R. Joseph Daugherty	Vice President
Todd A. Travers	Secretary
J. Kevin Ciavarra	Assistant Secretary
Chad Schramek	Treasurer
Prospect Street High Income Portfolio, Inc. and Prospect Street Income Shares Inc.
James D. Dondero, Director	President
Mark K. Okada	Executive Vice President
R. Joseph Daugherty, Director	Senior Vice President
M. Jason Blackburn	Secretary and Treasurer
Michael S. Minces	Chief Compliance Officer
Timothy K. Hui, Director	Associate Provost for Graduate Education of the Pennsylvania Biblical University, 48 Willow Green Drive, Churchville, Pennsylvania 18966
Scott F. Kavanaugh, Director	Private investments
James F. Leary, Director	Managing Director of Benefit Capital Southwest, Inc., 2006 Peakwood Drive, Garland, Texas 75044
Bryan A. Ward, Director	Senior Manager of Accenture, LLP, 3625 Rosedale, Dallas, Texas 75205

EX-99.2

EXHIBIT 99.2

HIGHLAND CAPITAL MANAGEMENT, L.P.
1300 Two Galleria Tower
13455 Noel Road, LB 45
Dallas, Texas 75240

October 25, 2005

Via Certified Mail

Board of Directors
Motient Corporation
300 Knightsbridge Pkwy.
Lincolnshire, Illinois 60069

Ladies and Gentlemen:

I received notice on Monday of this week of a meeting of the Board of Directors (the “Board”) of Motient Corporation (the “Company”) that is now apparently scheduled for 9:00 a.m. tomorrow. After my subsequent request for the material to be covered at such meeting, I was provided with a copy of proposed resolutions to be discussed. I also received a copy of a letter from the Company dated October 24, 2005, responding to my letter to you of last week concerning the disclosures and omissions in the documents related to the exchange offer commenced by the Company on September 27, 2005 and subsequently amended (the “Exchange Offer”).

First, to my knowledge, the Company has not duly called any meetings (other than the meeting held on September 26, 2005) to substantively discuss the Exchange Offer. If the Board held other meetings to discuss these matters, they were called without valid notice to all Board members and thus the decisions made are not valid. At the meeting held on September 26, 2005, the Board may have authorized the Exchange Offer (with me abstaining because of the lack of time provided to directors to review the proposed offer), but the Board did not “carefully consider” or become “apprised of all material facts” relating to the Exchange Offer, as suggested in the proposed resolutions for tomorrow’s meeting. Specifically the Board did not discuss, deliberate and “become apprised of all material facts” relating to: (i) the terms of the proposed offer; (ii) any recommendation or lack thereof to the Series A Preferred holders; (iii) the value of the Series B Preferred being issued or whether a fairness opinion had been obtained; (iv) a release of insiders and outside counsel; and (v) any amendments to the Registration Rights Agreement. The only conclusion that can be drawn is that this hastily-called meeting is designed to rectify the previous lack of deliberation and consideration of these issues by the Board. Thus, I request that the resolutions be revised to reflect the actual prior deliberations (or lack thereof) of the Board consistent with Delaware law.

Second, the proposed resolutions of the Company present a number of issues (in addition to the ones referred to above) that need to be explained, clarified and revised. It would appear that the meeting tomorrow has been called in haste without due consideration of the issues raised by the Exchange Offer or my recent letter regarding the Exchange Offer. For example, the resolutions refer to an “Interested Party Transaction” and appear to refer to Highland Capital’s beneficial ownership of Series A Preferred shares. What about the releases for the officers and directors included in the Exchange Offer? Are these not “Interested Party Transactions”? Although the resolutions refer to “fairness,” they do not detail the

methodology or standard by which any Board member could conclude that the transaction is fair. How can a Board member reach this conclusion (which must meet a heightened standard under Delaware law) when the Company has failed to provide the requisite information and accurate disclosures? How can a Series A Preferred holder conclude (as suggested in the Company’s letter to holders dated October 19, 2005), that the value of the aggregate gross proceeds from the issuance of the Series B Preferred shares does not exceed $250 million, so as not to require a redemption of the Series A Preferred shares not exchanged? Where is this valuation issue addressed by the Board? This transaction should only be approved after extensive deliberation by the Board after it has been provided with the requisite background information.

Finally, I am concerned that certain important issues have not been adequately answered, including:

• The Company’s statement that it “should be able to register the shares of common stock underlying [the holder’s] shares of Series B Preferred.” (emphasis is mine). Can the Company register the Series B Preferred or not? What factors determine this possibility? What if the Series B Preferred cannot be registered?

• The Company’s continued lack of disclosure regarding the releases obtained from tendering Series A Preferred holders, stating in its October 24, 2005 letter to me that “with regards to the scope of the releases, we would simply note that a holder of Series A Preferred Stock who exchanges for Series B Preferred Stock will have claims with respect to the Series B Preferred stock rather than the Series A Preferred, thus substituting one set of claims for another.” Do the releases effectively release no claims? What claims will Series B Preferred holders have once the releases are executed?

• The Company’s statement that “Motient has no present intention of redeeming or rescinding Mr. Dondero’s Series A Preferred, or the Series A Preferred of any other holder.” Despite your intention not to redeem or rescind the shares of Series A Preferred, this does not change the fact that the Series A Preferred is still subject to litigation seeking rescission. I find it curious that you would inform the holders of Series A Preferred that you “may never be able to register [a Series A Preferred holder’s] resale,” and yet omit the potential value of a rescission offer to such holder, especially in light of Motient’s declining stock price and the possible dilution resulting from the proposed transaction with Mobile Satellite Ventures, LP. Also, the Company continues to ignore the fact that the proposed transaction (as publicly disclosed) may be impossible to consummate under the terms of the Series A Preferred if any Series A Preferred is not exchanged.

In addition to the materials I have requested above, in my role as a member of the Board I hereby request that you provide me with the following materials prior to any meeting where the Exchange Offer is considered:

• All minutes or resolutions (whether draft or executed) of the Company’s Executive Committee since its creation;

• Any documents conferring upon the Company’s Executive Committee its authority and/or powers;

• Any documents or correspondence from the Company’s Audit Committee received by the Board or Executive Committee in connection with the supposed “investigation” by the Audit Committee of any issues in connection with the Exchange Offer;

• Any valuations by third party experts received in connection with the Exchange Offer;

• Copies of all correspondence received from the Securities and Exchange Commission relating to the Exchange Offer;

• An indication of which holders have tendered their shares of Series A Preferred under the Exchange Offer; and

• Information regarding the status of the proposed transaction with Mobile Satellite Ventures, LP and the effect of the Exchange Offer on this proposed transaction.

Despite the Executive Committee’s arrogation of power and secretive decision process, I remain a director entitled to full and accurate information rather than to be excluded from deliberations, and I request that if you are not willing to provide the foregoing to me prior to our meeting, that you address each of these issues at the meeting and provide me with written answers and responses to each of the questions I raise, which should also be included in the minutes of the meeting.

Each director should independently consider his or her obligations under Delaware law and exercise the requisite due diligence to ensure that the disclosures in the Exchange Offer documents are true and correct before any exchanges are accepted. You should not rely on your ability to cure these errors in the future by merely offering a new “Series C Preferred.”

Sincerely,

/s/ James D. Dondero

James D. Dondero

cc: Securities and Exchange Commission

EX-99.3

EXHIBIT 99.3

HIGHLAND CAPITAL MANAGEMENT, L.P.
1300 Two Galleria Tower
13455 Noel Road, LB 45
Dallas, Texas 75240

October 26, 2005

Via Certified Mail

Motient Corporation
300 Knightsbridge Pkwy.
Lincolnshire, Illinois 60069
Attn: Mr. Robert L. Macklin, Esq.

Re: Notice of Non-Exchange of Shares in Connection with Motient Corporation Exchange Offer

Dear Mr. Macklin:

The undersigned is providing you this letter on behalf of Highland Capital Management, L.P., Highland Crusader Offshore Partners, L.P., Highland Equity Focus Fund, L.P. and Highland Capital Management Services, Inc. (collectively, the “Highland Parties”) to inform you that the Highland Parties will not be exchanging their shares of Series A Convertible Preferred Stock for shares of Series B Convertible Preferred Stock pursuant to the Exchange Offer commenced by Motient Corporation on September 27, 2005 and as thereafter amended.

Very truly yours,
Highland Capital Management, L.P.
By:	Strand Advisors, Inc.,
	its general partner
By:	/s/ J. Kevin Ciavarra
Name:	J. Kevin Ciavarra
Title:	Officer

EX-99.4

EXHIBIT 99.4

JAMES D. DONDERO
1300 Two Galleria Tower
13455 Noel Road, LB 45
Dallas, Texas 75240

October 26, 2005

Via Certified Mail

Board of Directors
Motient Corporation
300 Knightsbridge Pkwy.
Lincolnshire, Illinois 60069

Ladies and Gentlemen:

At today’s meeting of the Board of Directors (the “Board”) of Motient Corporation (the “Company”) to “discuss” and then to finally approve the terms of the already-commenced exchange offer and the related issuance of the Series B Preferred stock (the “Exchange Offer”), the Board avoided significant issues with respect to the Exchange Offer and rushed to another quick decision without discussion.

My letters to you dated October 19 and October 25, 2005, set forth detailed questions relating to the Exchange Offer that should have been reviewed and discussed before approving the Exchange Offer. These issues were not discussed and, in fact, given the way in which the meeting was conducted, it was clear that there was no desire to deal with these issues and address these legitimate concerns. Today’s meeting merely recited the terms of the Series B Preferred. Resolutions inaccurately state that the members of the Board had carefully considered the Exchange Offer and had become “apprised of all material facts.” As previously noted, the corporate governance of the Company is in desperate need of repair, and the Company’s stockholders deserve more than the maintenance to the continued corporate fiction.

Highland Capital Management, L.P. and certain of its affiliates today notified the Company that they elected not to participate in the Exchange Offer because they believe that the Company has not adequately disclosed all material information relating to the Exchange Offer and its implications to stockholders. Highland and I have also been given indications that various side deals and side letters may have been proffered to some Series A Preferred holders to encourage their exchange. If the Company entered into agreements with Series A Preferred holders prior to tendering, Highland and I suspect that these deals may violate the securities laws and should be disclosed. These sorts of indications, as well as prior concerns that I have expressed in my correspondence with the Board, continue to raise serious concerns for both me and Highland regarding the Board’s conduct in connection with the Exchange Offer, particularly the inadequacy of the Company’s disclosures.

Sincerely,

/s/ James D. Dondero

James D. Dondero

cc: Securities and Exchange Commission