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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. 15 )*

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 800
Dallas, Texas 75240
(972) 628-4100

(Name, Address and Telephone Number of Person Authorized to
Receive Notices and Communications)

February 15, 2006

(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  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			1,155,224
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			1,155,224
WITH		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):
	1.8%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	CO/IV

CUSIP No. 619908304  Page 3  of  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			111,940
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			111,940
WITH		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  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			223,880
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			223,880
WITH		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):
	0.4%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	OO

CUSIP No. 619908304  Page 5  of  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			5,352,497
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			5,352,497
WITH		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):
	8.6%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	PN

CUSIP No. 619908304  Page 6  of  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			223,880
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			223,880
WITH		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):
	0.4%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	OO

CUSIP No. 619908304  Page 7  of  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			1,518,779
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			1,518,779
WITH		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):
	2.4%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	PN

CUSIP No. 619908304  Page 8  of  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			119,283
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			119,283
WITH		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  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			182,748
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			182,748
WITH		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  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			8,822,764
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			8,822,764
WITH		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):
	14.1%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	IA/PN

CUSIP No. 619908304  Page 11  of  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			8,822,764
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			8,822,764
WITH		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):
	14.1%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	CO

CUSIP No. 619908304  Page 12  of  16 

1	NAMES OF REPORTING PERSONS: 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
		7	SOLE VOTING POWER:
NUMBER OF			9,024,326
SHARES		8	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			9,024,326
WITH		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):
	14.4%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	IN

Page 13 of 16

     This Amendment No. 15 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, Amendment No. 9 to Schedule 13D filed with the Commission on October 21, 2005, Amendment No. 10 to Schedule 13D filed with the Commission on October 27, 2005, Amendment No. 11 to Schedule 13D filed with the Commission on November 17, 2005, Amendment No. 12 to Schedule 13D filed with the Commission on December 8, 2005, Amendment No. 13 to Schedule 13D filed with the Commission on January 30, 2006, and Amendment No. 14 to Schedule 13D filed with the Commission on February 14, 2006 (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 February 15, 2006, Highland Legacy Limited delivered to Motient Corporation (the “Company”) a demand letter, pursuant to Section 220 of the Delaware General Corporation Law, to inspect certain books, records, and documents of the Company. A copy of the letter is attached hereto as Exhibit 99.11.

     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.

Item 7. Material to be Filed as Exhibits.

     Item 7 is hereby amended and supplemented as follows:

Exhibit 99.11 Letter of Highland Legacy Limited to Motient Corporation, dated February 14, 2006.

Page 14 of 16

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: February 15, 2006
	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

Page 15 of 16

HIGHLAND CRUSADER OFFSHORE PARTNERS, L.P.
By:	Highland Crusader Fund GP, L.P., its general partner
By:	Highland Crusader GP, LLC, its general partner
By:	Highland Capital Management, L.P., its sole member
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President
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 Equity Focus Fund GP, L.P., its general partner
By:	Highland Equity Focus GP, LLC, its general partner
By:	Highland Capital Management, L.P., its sole member
By:	Strand Advisors, Inc., its general partner
	By:	/s/ James Dondero
	Name:	James Dondero
	Title:	President
HIGHLAND SELECT EQUITY FUND, L.P.
By:	Highland Select Equity Fund GP, L.P., its general partner
By:	Highland Select Equity GP, LLC, its general partner
By:	Highland Capital Management, L.P., its sole member
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 16 of 16

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 800, 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-99.11

EXHIBIT 99.11

February 14, 2006

VIA FACSIMILE
AND FEDERAL EXPRESS

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

     Re:       Demand to Inspect Stock List

Dear Mr. Macklin:

     Highland Legacy Limited (“HLL”) is the record owner of one hundred (100) shares of Common Stock of Motient Corporation, a Delaware corporation (the “Company”). Attached is documentary evidence of HLL’s record ownership and such documentary evidence is a true and correct copy of what it purports to be. Pursuant to Section 220 of the Delaware General Corporation Law (the “DGCL”), as the record owner of the shares of Common Stock stated above, HLL hereby demands, under oath, that it and its attorneys, representatives and agents be given, during regular business hours, the opportunity to inspect the following books, records and documents of the Company and to make copies or extracts therefrom:

     (a) A complete record or list of the holders of common stock, par value $.01 per share, of the Company (the “Common Stock”), certified by the Company’s transfer agent(s) and/or registrar(s), setting forth the name and address of, and the number of shares of Common Stock of the Company held by, each stockholder;

     (b) Relating to the list of stockholders referred to in paragraph (a), a magnetic computer tape or other electronic medium containing such list, showing the name and address of each such stockholder and the number of shares of Common Stock registered in the name of each such stockholder as of the most recent date available, together with the computer processing data necessary for HLL and its attorneys, representatives and agents to make use of such list on magnetic computer tape or other electronic medium and a hard copy printout of such list in order of descending balance for verification purposes;

     (c) All daily transfer sheets showing changes in the names and addresses of the holders of Common Stock and the number of shares of Common Stock of the Company held by the Company’s stockholders that are in or come into the possession of the Company or its transfer agent, or that can

February 14, 2006
Page 2

reasonably be obtained from brokers, dealers, banks, clearing agencies or voting trusts or their nominees from the date of the stockholder list referred to in paragraph (a);

     (d) A stop transfer list or stop list relating to any shares of Common Stock of the Company and any additions, deletions, changes or corrections made thereto;

     (e) All information in or that comes into the Company’s or its transfer agent(s)’ or registrar(s)’ possession or control or that can reasonably be obtained from brokers, dealers, banks, clearing agencies, voting trusts or their nominees relating to the names and addresses of and number of shares of Common Stock of the Company held by the participating brokers and banks named in the individual nominee names of Cede & Co. or other similar depositories or nominees, including respondent bank lists, and all omnibus proxies and related respondent bank proxies and listings issued pursuant to Rule 14b-2 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”);

     (f) All information in or that comes into the Company’s possession or that can reasonably be obtained from brokers, dealers, banks, clearing agencies, voting trusts or their nominees relating to the names of the non-objecting beneficial owners of the Common Stock of the Company pursuant to Rule 14b-1(c) or Rule 14b-2(c) under the Exchange Act, on magnetic computer tape or other electronic medium, such computer processing data as is necessary for HLL and its attorneys, representatives and agents to make use of such information on magnetic computer tape or other electronic medium, and a hard copy printout of such information in order of descending balance for verification purposes (the “non-objecting beneficial owners” or “NOBO list”). If such information is not in the Company’s possession, custody or control, such information should be requested from Automatic Data Processing — Investor Communications Services; and

     (g) All lists on computer tapes or other electronic media and the relevant processing data and printouts (as described in paragraph (b) above) containing the name and address of and number of shares of Common Stock of the Company attributable to any participant in any employee stock ownership plan, employee stock purchase plan or other employee compensation or benefit plan of the Company in which the decision to vote shares of stock of the Company held by such plan is made, directly or indirectly, individually or collectively, by the participants in the plan and the method(s) by which HLL or its attorneys, representatives or agents may communicate with each such participant, as well as the name, affiliation and telephone number of the trustee or administrator of each such plan, and a detailed explanation of the treatment not only of shares for which the trustee or administrator receives instructions from participants, but also shares for which either the trustee or administrator does not receive instructions or shares that are outstanding in the plan but are unallocated to any participant.

     For purposes of the foregoing demand, we request the Company provide or otherwise make available all such information as of the date hereof, or as of the most recent date when such information was available, and as of any record date that may have already been established or is subsequently established for any annual or special meeting or consent solicitation that may be called or initiated by the Company or any stockholder or group of stockholders of the Company for the purpose of removing and/or electing directors, or any adjournment or postponement thereof, and any other record date that may be established as a new or substituted record date for any other meeting of stockholders or consent solicitation in lieu thereof and any adjournments, postponements, reschedulings or continuations thereof.

     HLL further demands that all modifications, additions or deletions to any and all information referred to above be immediately furnished as such modifications, additions or deletions become available

February 14, 2006
Page 3

to the Company or its agents or representatives from the date hereof until any Annual Meeting of Stockholders for 2006.

     HLL will bear the reasonable costs incurred by the Company including those of its transfer agent(s) or registrar(s) in connection with the production of the information demanded.

     The purpose of this demand is to enable HLL, in accordance with applicable law, to communicate with the Company’s stockholders on matters relating to their interests as stockholders, to consider, evaluate and plan a proxy or consent solicitation of the holders of the Company’s Common Stock to, among other things, change the number of directors, remove members of the board of directors and/or elect new directors and, should HLL determine to participate in a proxy or consent solicitation, to facilitate and support that solicitation.

     HLL hereby designates and authorizes Haynes and Boone, LLP, and any persons designated by Haynes and Boone, LLP, acting singly or in any combination, to conduct the inspection and copying herein requested. Please advise Brian N. Hail at 212.659.4962 as to the time and place when the requested information will be made available in accordance with this demand. Pursuant to Section 220 of the DGCL, you are required to respond to this demand within five (5) business days.

     If the Company contends that this request is incomplete or is otherwise deficient in any respect, please notify HLL immediately in writing, with a copy to Brian N. Hail of Haynes and Boone, LLP, 153 E 53^rd Street, Suite 4900, New York, NY 10022; Facsimile: 212.884.8202, setting forth the facts that the Company contends support its position and specifying any additional information believed to be required. In the absence of such prompt notice, HLL will assume that the Company agrees that this request complies in all respects with the requirements of the DGCL. HLL reserves the right to withdraw or modify this request at any time.

     Please acknowledge receipt of this letter and the enclosures by signing and dating the enclosed copy of this letter in the space provided below and returning the same to the undersigned in the enclosed envelope.

Very truly yours, Highland Legacy Limited By:  Highland Capital Management, L.P.,         as Collateral Manager By:  Strand Advisors, Inc.,         its general partner
By:	/s/ J. Kevin Ciavarra
	J. Kevin Ciavarra
	Assistant Secretary

February 14, 2006
Page 4

Receipt Acknowledged.

MOTIENT CORPORATION

By:

Name:

Title:

Date:

STATE OF TEXAS	)
	)	SS:
COUNTY OF DALLAS	)

     J. KEVIN CIAVARRA, having been first duly sworn, deposes and says that he is the Assistant Secretary of Strand Advisors, Inc., general partner of Highland Capital Management, L.P., collateral manager of Highland Legacy Limited, that he is authorized to execute the foregoing demand for inspection pursuant to Section 220 of the Delaware General Corporation Law and to make the demand designations, authorizations and representations contained therein, and that the facts and statements contained in the foregoing demand for inspection are true and correct.

/s/ J. Kevin Ciavarra

J. Kevin Ciavarra

SWORN TO AND SUBSCRIBED before me
this 14th day of February, 2006.

/s/ Cathy Chambers

Notary Public