Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
GREENHILL & CO INC
   2. Issuer Name and Ticker or Trading Symbol
Iridium Communications Inc. [IRDM] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
300 PARK AVENUE, 23RD FLOOR		 3. Date of Earliest Transaction (Month/Day/Year)
09/29/2009
(Street)

NEW YORK, NY 10022		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 09/29/2009   J(1)   1,441,176 D (1) 6,928,387 D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Warrant $ 7 09/29/2009   J(1)     16,369,563 09/29/2009   (3) Common Stock 16,369,563 (1) 0 D  
Warrant $ 11.5 09/29/2009   J(2)   4,000,000   09/29/2009   (2) Common Stock 4,000,000 (2) 4,000,000 D  
Convertible Subordinated Promissory Note (4) 09/29/2009   J(4)   0 (4)   10/24/2009   (4) Common Stock (4) (4) 0 (4) I See footnote (5)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
GREENHILL & CO INC
300 PARK AVENUE
23RD FLOOR
NEW YORK, NY 10022		     X    

Signatures

 /s/ Ulrika Ekman   10/01/2009
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The shares of common stock, par value $0.001 per share ("Common Stock"), and warrants ("Warrants") were purchased as part of units (each a "Unit") sold in the initial public offering of GHL Acquisition Corp., the prior name of Iridium Communications Inc. (the "Issuer"), at a price of $10.00 per Unit. Each Unit consisted of one share of Common Stock and one Warrant. Each Warrant entitled the holder to purchase one share of Common Stock for $7.00 per share. Pursuant to letter agreements dated September 22, 2008 and April 28, 2009, Greenhill & Co., Inc. agreed to forfeit (a) 1,441,176 shares of Common Stock and (b) 12,369,563 Warrants on September 29, 2009.
(2) On September 29, 2009, the remaining Warrants were exchanged for restructured warrants on substantially similar terms, with the exception of: (i) increasing their exercise price to $11.50, (ii) extending their exercise period by two years to February 14, 2015, and (iii) increasing the price of Common Stock at which the warrants can be redeemed by the Issuer to $18.00. Such transactions were approved in advance by the Issuer's Board of Directors.
(3) Expires on the earlier of February 14, 2013, or the business day preceding the date on which the Warrants are redeemed.
(4) Pursuant to that certain $22.9 million Convertible Subordinated Promissory Note (the "Note") dated October 24, 2008 issued by Iridium Holdings LLC to Greenhill & Co. Europe Holdings Limited ("Greenhill Europe"), a wholly owned subsidiary of Greenhill & Co., Inc., Greenhill Europe has the right to convert the Note into Class A Units of Iridium Holdings LLC (the "Class A Units") equal to the Note Payment Amount (as defined in the Note) divided by the Conversion Price (as defined in the Note). Such Class A Units are exchangeable for shares of Common Stock at the ratio of 23.1936 shares per Class A Unit. The Note is provided as Exhibit 99.1 attached hereto.
(5) The note is held by Greenhill Europe, a wholly owned subsidiary of Greenhill & Co., Inc.

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