10-Q/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

_________________________________

FORM 10-Q/A

(Amendment No. 1)

 (Mark One)

þ	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the quarterly period ended June 30, 2011

OR

o	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the transition period from ______ to ______

Commission file number 1-14279

____________________________________

ORBITAL SCIENCES CORPORATION

(Exact name of registrant as specified in charter)

Delaware	06-1209561
(State of Incorporation of Registrant)	(I.R.S. Employer Identification No.)

21839 Atlantic Boulevard

Dulles, Virginia  20166

(Address of principal executive offices)

(703) 406-5000

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yes þ  No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).  Yes þ  No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company.  See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.  (Check one):

Large accelerated filer þ                                            Accelerated filer o      Non-accelerated filer o       Smaller reporting company o

(Do not check if a smaller reporting company)

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes o  No þ

As of July 26, 2011, 58,459,394 shares of the registrant’s Common Stock were outstanding.

EXPLANATORY NOTE

The sole purpose of this amendment to Orbital Sciences Corporation’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2011, originally filed with the Securities and Exchange Commission on July 29, 2011 (the “Form 10-Q”), is to furnish Exhibit 101 to the Form 10-Q in accordance with Rule 405 of Regulation S-T.  Exhibit 101 to this report provides the consolidated financial statements and related notes from the Form 10-Q formatted in XBRL (eXtensible Business Reporting Language).

No other changes have been made to the Form 10-Q.  This Form 10-Q/A does not reflect events that may have occurred subsequent to the original filing date, and does not modify or update in any way disclosures made in the Form 10-Q.

Pursuant to Rule 406T of Regulation S-T, the Interactive Data Files in Exhibit 101 hereto are deemed not filed or part of a registration statement or prospectus for purposes of Sections 11 or 12 of the Securities Act of 1933, as amended, are deemed not filed for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended, and otherwise are not subject to liability under those sections.

EXHIBITINDEX

The following exhibits are filed with this report unless otherwise indicated.

Exhibit No.	Description
3.1*	Restated Certificate of Incorporation (incorporated by reference to Exhibit 4.1 to the company’s Registration Statement on Form S-3 (File Number 333-08769) filed and effective on July 25, 1996).
3.2*	Amended and Restated Bylaws (incorporated by reference to Exhibit 3.2 to the company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2005).
3.3*	Certificate of Amendment to Restated Certificate of Incorporation, dated April 29, 1997 (incorporated by reference to Exhibit 3.3 to the company’s Annual Report on Form 10-K for the fiscal year ended December 31, 1998).
3.4*	Certificate of Amendment to Restated Certificate of Incorporation, dated April 30, 2003 (incorporated by reference to Exhibit 3.4 to the company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2003).
4.1*	Form of Certificate of Common Stock (incorporated by reference to Exhibit 4.1 to the company’s Registration Statement on Form S-1 (File Number 33-33453) filed on February 9, 1990 and effective on April 24, 1990).
4.2*	Indenture dated as of December 13, 2006, by and between Orbital Sciences Corporation and The Bank of New York, as Trustee (incorporated by reference to Exhibit 4.1 to the company’s Current Report on Form 8-K filed on December 13, 2006).
4.3*	Form of 2.4375% Convertible Senior Subordinated Note due 2027 (incorporated by reference to Exhibit 4.2 to the company’s Current Report on Form 8-K filed on December 13, 2006).
10.1*	Credit Agreement, dated as of June 7, 2011, by and among Orbital Sciences Corporation, as Borrower, the subsidiaries of the Borrower party thereto as Guarantors, the Lenders party thereto, and Wells Fargo Bank, National Association, as Administrative Agent, Swingline Lender and Issuing Lender,  Wells Fargo Securities LLC, Citigroup Global  Markets Inc. and Merrill Lynch, Pierce, Fenner & Smith Incorporated as Joint Lead Arrangers and Joint Bookrunners, Citibank, N.A. and Bank of America, N.A. as Co-Syndication Agents and PNC Bank, N.A. and Sovereign Bank as Co-Documentation Agents (incorporated by reference to Exhibit 10.1 to the company’s Current Report on Form 8-K filed on June 10, 2011).
10.2 *	Security and Pledge Agreement, dated as of June 7, 2011, between Orbital Sciences Corporation, the other obligors party thereto, and Wells Fargo Bank, National Association, as Administrative Agent (incorporated by reference to Exhibit 10.2 to the company’s Current Report on Form 8-K filed on June 10, 2011).
31.1*	Certification of Chairman, President and Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section 1350) (transmitted herewith).
31.2*	Certification of Vice Chairman and Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section 1350) (transmitted herewith).
32.1*	Written Statement of Chairman, President and Chief Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section 1350) (transmitted herewith).
32.2*	Written Statement of Vice Chairman and Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section 1350) (transmitted herewith).
101.INS**	XBRL Instance Document
101.SCH**	XBRL Taxonomy Extension Schema
101.CAL**	XBRL Taxonomy Extension Calculation Linkbase
101.LAB**	XBRL Taxonomy Extension Labels Linkbase
101.PRE**	XBRL Taxonomy Extension Presentation Linkbase
101.DEF**	XBRL Taxonomy Extension Definition Linkbase

*   Previously Filed

** Filed with this Form 10-Q/A

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	ORBITAL SCIENCES CORPORATION
DATED:  August 29, 2011	By:	/s/ Hollis M. Thompson
		Hollis M. Thompson
		Senior Vice President, Corporate Controller and Chief Accounting Officer

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CONDENSED CONSOLIDATED INCOME STATEMENTS (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
CONDENSED CONSOLIDATED INCOME STATEMENTS [Abstract]
Revenues	$ 350,599	$ 337,726	$ 668,302	$ 633,916
Cost of revenues	282,758	271,297	553,798	499,199
Research and development expenses	23,432	30,268	40,567	60,431
Selling, general and administrative expenses	21,602	23,933	41,013	44,693
Income from operations	22,807	12,228	32,924	29,593
Interest income and other	703	408	12,192	746
Interest expense	(2,804)	(2,341)	(5,337)	(4,702)
Income before income taxes	20,706	10,295	39,779	25,637
Income tax benefit (provision)	511	(3,950)	(6,227)	(10,024)
Net income	$ 21,217	$ 6,345	$ 33,552	$ 15,613
Basic income per share	$ 0.36	$ 0.11	$ 0.57	$ 0.27
Diluted income per share	$ 0.36	$ 0.11	$ 0.56	$ 0.27

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CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating Activities:
Net income	$ 33,552	$ 15,613
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization expense	16,476	11,393
Deferred income taxes	4,055	7,170
Stock-based compensation and other	7,102	6,188
Changes in assets and liabilities, net of effect of acquisition	6,777	(93,584)
Net cash provided by (used in) operating activities	67,962	(53,220)
Investing Activities:
Capital expenditures	(32,774)	(33,591)
Payment for business acquisition	0	(55,000)
Net cash used in investing activities	(32,774)	(88,591)
Financing Activities:
Net proceeds from issuances of common stock	1,364	10,311
Debt issuance costs	(2,938)	0
Tax benefit of stock-based compensation	713	1,958
Net cash (used in) provided by financing activities	(861)	12,269
Net increase (decrease) in cash and cash equivalents	34,327	(129,542)
Cash and cash equivalents, beginning of period	252,415	372,986
Cash and cash equivalents, end of period	$ 286,742	$ 243,444

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Comprehensive Income (Tables)

6 Months Ended

Jun. 30, 2011

Comprehensive Income [Abstract]

Comprehensive Income

Comprehensive income consisted of the following (in thousands):

	Quarters Ended June 30,						Six Months Ended June 30,
	2011			2010			2011			2010
Net income	$	21,217		$	6,345		$	33,552		$	15,613
Unrealized gain (loss) on investments		500			—			1,100			(500	)
Defined benefit plans, net of tax		(155	)		(447	)		(127	)		(281	)
Total comprehensive income	$	21,562		$	5,898		$	34,525		$	14,832

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Document And Entity Information (USD $)	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Entity Registrant Name	ORBITAL SCIENCES CORP /DE/
Entity Central Index Key	0000820736
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	No
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$ 900,496,000
Entity Common Stock, Shares Outstanding	58,458,374
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2011

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Business Acquisition and Goodwill (Details) (Spacecraft Business, USD $) In Millions	3 Months Ended
	Jun. 30, 2011	Apr. 02, 2010
Spacecraft Business
Business Acquisition [Line Items]
Amount of cash paid to acquire certain assets and liabilities		$ 55
Goodwill Purchase Accounting Adjustment [Abstract]
Goodwill Purchase Accounting Adjustments	$ 0.5

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Debt

6 Months Ended

Jun. 30, 2011

Debt [Abstract]

Debt

(8)  Debt

Convertible Notes

On December 13, 2006, the company issued $143.8 million of 2.4375% convertible senior subordinated notes due 2027 with interest payable semi-annually each January 15 and July 15.  As of June 30, 2011 and December 31, 2010, the net carrying amount of the convertible notes was $128.3 million and $125.5 million, respectively, and the related unamortized debt discount was $15.5 million and $18.3 million, respectively.

Under certain circumstances, the convertible notes are convertible into cash, or a combination of cash and common stock at the company’s election, based on an initial conversion rate of 40.8513 shares of the company’s common stock per $1,000 in principal amount of the convertible notes (equivalent to an initial conversion price of approximately $24.48 per share).  At any time on or after January 21, 2014, the convertible notes are subject to redemption at the option of the company, in whole or in part, for cash equal to 100% of the principal amount of the convertible notes, plus unpaid interest, if any, accrued to the redemption date.  Holders of the convertible notes may require the company to repurchase the convertible notes, in whole or in part, on January 15, 2014, January 15, 2017 or January 15, 2022, or, if a “fundamental change” (as such term is defined in the indenture governing the convertible notes) occurs, for cash equal to 100% of the principal amount of the convertible notes, plus any unpaid interest, if any, accrued to the redemption date.

The fair value of the company’s convertible notes at June 30, 2011 and December 31, 2010 was estimated at $149.0 million and $150.2 million, respectively.  The fair value was determined based on market prices quoted by a broker-dealer.

Credit Facility

In June 2011, the company entered into a five-year $300 million revolving secured credit facility (“Credit Facility”), which replaced the company’s $100 million revolving credit facility that was established in 2007.  All letters of credit outstanding under the terminated credit facility were transferred to the Credit Facility.  The Credit Facility has a scheduled maturity date of June 7, 2016.  The company’s obligations under the Credit Facility are secured by substantially all of the company’s personal property assets.

The Credit Facility provides capacity for up to $300 million of revolving loans and permits the company to utilize up to $125 million of such capacity for the issuance of standby letters of credit.  The company has the option to increase the amount of the Credit Facility by up to $150 million to the extent that any one or more lenders, whether or not currently party to the Credit Facility, commits to be a lender for such amount.  Loans under the Credit Facility bear interest at LIBOR plus an applicable margin ranging from 1.75% to 2.50%, with the applicable margin varying according to the company’s total leverage ratio, or, at the election of the company, at a prime base rate plus 0.75% to 1.50%.  Letters of credit issued under the Credit Facility accrue fees at a rate equal to the applicable margin for LIBOR loans.  In addition, the company is required to pay a commitment fee for the unused portion of the Credit Facility, if any, at a quarterly rate ranging from 0.30% to 0.50%.

As of June 30, 2011, there were no borrowings under the Credit Facility, although $17.7 million of letters of credit were issued under the Credit Facility.  Accordingly, as of June 30, 2011, $282.3 million of the Credit Facility was available for borrowings.

Debt Covenants

Orbital’s Credit Facility contains covenants limiting its ability to, among other things, pay cash dividends, incur debt or liens, redeem or repurchase company stock, enter into transactions with affiliates, make investments, merge or consolidate with others or dispose of assets.  In addition, the Credit Facility contains financial covenants with respect to leverage and interest coverage.

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Industry Segment Information (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Segment Reporting Information [Line Items]
Revenues	$ 350,599,000	$ 337,726,000	$ 668,302,000	$ 633,916,000
Operating income	22,807,000	12,228,000	32,924,000	29,593,000
Identifiable assets	1,224,257,000		1,224,257,000		1,062,536,000
Capital expenditures	15,458,000	18,494,000	32,774,000	33,591,000
Depreciation and amortization	8,629,000	6,150,000	16,476,000	11,393,000
Intersegment revenues	22,100,000	18,300,000	55,100,000	30,500,000
Launch Vehicles [Member]
Segment Reporting Information [Line Items]
Revenues	131,367,000	95,702,000	236,640,000	196,044,000
Operating income	6,870,000	3,469,000	1,821,000	8,000,000
Identifiable assets	200,116,000		200,116,000		212,360,000
Capital expenditures	10,184,000	12,209,000	20,696,000	22,425,000
Depreciation and amortization	3,952,000	1,808,000	7,272,000	3,614,000
Intersegment revenues	20,300,000	16,500,000	51,700,000	27,000,000
Satellites and Space Systems [Member]
Segment Reporting Information [Line Items]
Revenues	138,174,000	139,423,000	290,833,000	239,944,000
Operating income	8,474,000	7,512,000	18,784,000	15,219,000
Identifiable assets	293,661,000		293,661,000		268,804,000
Capital expenditures	2,016,000	1,797,000	3,845,000	3,327,000
Depreciation and amortization	2,805,000	2,515,000	5,516,000	4,780,000
Intersegment revenues	1,300,000	1,500,000	2,500,000	2,800,000
Advanced Space Programs [Member]
Segment Reporting Information [Line Items]
Revenues	103,188,000	120,926,000	195,898,000	228,469,000
Operating income	7,463,000	2,867,000	12,319,000	7,994,000
Identifiable assets	307,228,000		307,228,000		188,184,000
Capital expenditures	2,480,000	3,672,000	7,196,000	6,182,000
Depreciation and amortization	118,000	116,000	235,000	119,000
Intersegment revenues	500,000	300,000	900,000	700,000
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	(22,130,000)	(18,325,000)	(55,069,000)	(30,541,000)
Operating income	0	(1,620,000)	0	(1,620,000)
Identifiable assets	423,252,000		423,252,000		393,188,000
Capital expenditures	778,000	816,000	1,037,000	1,657,000
Depreciation and amortization	$ 1,754,000	$ 1,711,000	$ 3,453,000	$ 2,880,000

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Research and Development (Tables)

6 Months Ended

Jun. 30, 2011

Research and Development [Abstract]

Project Research and Development Expenses Incurred and Amounts Funded

The following table summarizes the COTS project research and development expenses incurred and amounts funded by NASA (in millions):

	Second Quarter				First Six Months				Inception
	2011		2010		2011		2010		To Date
Research and development costs incurred (1)	$	36.5	$	38.9	$	78.4	$	67.2	$	337.5
Less - amounts funded by NASA		25.2		18.1		59.3		33.1		211.6
Net research and development expenses	$	11.3	$	20.8	$	19.1	$	34.1	$	125.9

(1) Includes associated general and administrative expenses.

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Commitments and Contingencies

6 Months Ended

Jun. 30, 2011

Commitments and Contingencies [Abstract]

Commitments and Contingencies

(13)  Commitments and Contingencies

U.S. Government Contracts

The accuracy and appropriateness of costs charged to U.S. Government contracts are subject to regulation, audit and possible disallowance by the Defense Contract Audit Agency or other government agencies.  Accordingly, costs billed or billable to U.S. Government customers are subject to potential adjustment upon audit by such agencies.

Most of the company's U.S. Government contracts are funded incrementally on a year-to-year basis.  Changes in government policies, priorities or funding levels through agency or program budget reductions by the U.S. Congress or executive agencies could materially adversely affect the company's financial condition or results of operations.  Furthermore, contracts with the U.S. Government may be terminated or suspended by the U.S. Government at any time, with or without cause.  Such contract suspensions or terminations could result in unreimbursable expenses or charges or otherwise adversely affect the company's financial condition and/or results of operations.

Research and Development Expenses

The company believes that a majority of the company's research and development expenses are recoverable and billable under contracts with the U.S. Government, from which the majority of the company's revenues are derived.  Charging practices relating to research and development and other costs that may be charged directly or indirectly to government contracts are subject to audit by U.S. Government agencies to determine if such costs are reasonable and allowable under government contracting regulations and accounting practices.  The company believes that research and development costs incurred in connection with the company's Taurus II development program (see Note 11) are allowable, although the U.S. Government has not yet made a final determination.  If such costs were determined to be unallowable, the company could be required to record revenue and profit reductions in future periods.

Terminated Contracts

In 2010, the Orion Launch Abort System contract was terminated for convenience by the customer.  The company has recognized its best estimates of the revenues and profit that will ultimately be realized in the final termination settlement.  However, because of the inherent judgments associated with termination costs and profit assessments, it is possible that the company could recognize material adjustments to earnings upon resolution of this matter.

In April 2011, the company negotiated a settlement with the customer, subject to U.S. Government ratification, with respect to the Kinetic Energy Interceptor contract that had been terminated in 2009.  The resolution of this matter did not have a material impact on the company's financial statements.

Litigation

From time to time the company is party to certain litigation or other legal proceedings arising in the ordinary course of business.  Because of the uncertainties inherent in litigation, the company cannot predict whether the outcome of such litigation or other legal proceedings will have a material adverse effect on the company's results of operations or financial condition.

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Earnings Per Share

6 Months Ended

Jun. 30, 2011

Earnings Per Share [Abstract]

Earnings Per Share

(4)  Earnings Per Share

The computation of basic and diluted earnings per share ("EPS") is as follows (in thousands, except per share amounts):

			Quarters Ended June 30,						Six Months Ended June 30,
Numerator			2011			2010			2011			2010
		Net income	$	21,217		$	6,345		$	33,552		$	15,613
		Percentage allocated to shareholders (1)		98.9	%		99.2	%		98.9	%		99.2	%
		Numerator for basic and diluted earnings per share	$	20,984		$	6,294		$	33,183		$	15,488
Denominator
		Denominator for basic earnings per share -
		weighted-average shares outstanding		58,422			57,682			58,361			57,373
		Dilutive effect of stock options		454			667			472			729
		Denominator for diluted earnings per share		58,876			58,349			58,833			58,102
Per share income
		Basic	$	0.36		$	0.11		$	0.57		$	0.27
		Diluted		0.36			0.11			0.56			0.27
_________________________
	(1)	Basic weighted-average shares outstanding		58,422			57,682			58,361			57,373
		Basic weighted-average shares outstanding and
		unvested restricted share units expected to vest		59,096			58,155			59,039			57,847
		Percentage allocated to shareholders		98.9	%		99.2	%		98.9	%		99.2	%

The calculation of EPS shown above excludes the income attributable to the company's unvested restricted stock units ("RSUs") from the numerator and excludes the impact of those units from the denominator.

For the quarter and six months ended June 30, 2011, diluted weighted-average shares outstanding included the effect of all stock options.  For the quarter and six months ended June 30, 2010, diluted weighted-average shares outstanding excluded the effect of less than 0.1 million of stock options that were anti-dilutive.  Diluted weighted-average shares outstanding also excluded the effect of the RSUs and the company's $143.8 million of 2.4375% convertible senior subordinated notes that were anti-dilutive.

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Research and Development (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Research and Development [Abstract]
Research and development expenses	$ 23,432,000	$ 30,268,000	$ 40,567,000	$ 60,431,000
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development costs incurred, inception to date	337,500,000		337,500,000
Less - amounts funded by NASA, inception to date	211,600,000		211,600,000
Net research and development expenses, inception to date	125,900,000		125,900,000
COTS Agreement - Cost-Sharing Arrangement Terms with NASA [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate cash milestone payments to partially fund project costs	288,000,000		288,000,000
Estimated total project costs	445,000,000		445,000,000
Deferred revenue and customer advances	49,900,000		49,900,000		25,200,000
Research and development costs incurred	36,500,000	38,900,000	78,400,000	67,200,000
Less - amounts funded by NASA	25,200,000	18,100,000	59,300,000	33,100,000
Net research and development expenses	11,300,000	20,800,000	19,100,000	34,100,000
Taurus II Development Program [Member]
Research and Development [Abstract]
Research and development expenses	$ 8,200,000	$ 7,800,000	$ 15,300,000	$ 23,100,000

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Stock-Based Compensation

6 Months Ended

Jun. 30, 2011

Stock-based compensation [Abstract]

Stock-Based Compensation

(10)  Stock-Based Compensation

The following tables summarize information related to the company's stock-based compensation:

	Restricted Stock Units						Stock Options
				Weighted Average						Weighted Average
	Number of			Measurement			Number of			Exercise
	Units			Date Fair Value			Options			Price
Outstanding at December 31, 2010		684,674			$	16.38		1,226,582			$	6.46
Granted (1)		26,860				17.47		-				-
Exercised		-				-		(135,971	)			4.60
Vested		(35,107	)			16.59		-				-
Forfeited		(8,145	)			16.73		-				-
Expired		-				-		(5,648	)			4.14
Outstanding at June 30, 2011		668,282			$	16.41		1,084,963	(2)		$	6.70

(1)   The fair value of restricted stock unit grants is determined based on the closing market price of Orbital's common stock on the date of grant.  Such value is recognized as expense over the service period, net of estimated forfeitures.

(2)     The weighted average remaining contractual term is 1.85 years.

	Quarters Ended June 30,
(in millions)	2011		2010
Stock-based compensation expense	$	1.5	$	1.7
Income tax benefit related to stock-based compensation expense		0.5		0.7
Intrinsic value of options exercised computed as the market
price on the exercise date less the price paid to exercise the options		0.5		1.2
Cash received from exercise of options		0.1		2.2
Tax benefit recorded as credits to additional paid-in capital related
to stock-based compensation transactions		0.2		0.4
	Six Months Ended June 30,
(in millions)	2011		2010
Stock-based compensation expense	$	2.9	$	3.5
Income tax benefit related to stock-based compensation expense		0.9		1.4
Intrinsic value of options exercised computed as the market
price on the exercise date less the price paid to exercise the options		1.8		5.4
Cash received from exercise of options		0.6		9.7
Tax benefit recorded as credits to additional paid-in capital related
to stock-based compensation transactions		0.7		2.0

	As of
(in millions)	June 30, 2011
Shares of common stock available for grant under stock-based incentive plans		1.3
Aggregate intrinsic value of restricted stock units that are expected to vest	$	11.3
Unrecognized compensation expense related to non-vested restricted stock units, expected to
be recognized over a weighted-average period of 1.80 years		6.1
Aggregate intrinsic value of stock options outstanding, all fully vested		11.0

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Industry Segment Information (Tables)

6 Months Ended

Jun. 30, 2011

Industry Segment Information [Abstract]

Operating Information and Identifiable Assets by Reportable Segment

The following table presents operating information and identifiable assets by reportable segment (in thousands):

	Quarters Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
Launch Vehicles:
Revenues(1)	$131,367		$95,702		$236,640		$196,044
Operating income	6,870		3,469		1,821		8,000
Identifiable assets	200,116		212,360	(2)	200,116		212,360	(2)
Capital expenditures	10,184		12,209		20,696		22,425
Depreciation and amortization	3,952		1,808		7,272		3,614
Satellites and Space Systems:
Revenues(1)	$138,174		$139,423		$290,833		$239,944
Operating income	8,474		7,512		18,784		15,219
Identifiable assets	293,661		268,804	(2)	293,661		268,804	(2)
Capital expenditures	2,016		1,797		3,845		3,327
Depreciation and amortization	2,805		2,515		5,516		4,780
Advanced Space Programs:
Revenues(1)	$103,188		$120,926		$195,898		$228,469
Operating income	7,463		2,867		12,319		7,994
Identifiable assets	307,228		188,184	(2)	307,228		188,184	(2)
Capital expenditures	2,480		3,672		7,196		6,182
Depreciation and amortization	118		116		235		119
Corporate and Other:
Revenues(1)	$(22,130	)	$(18,325	)	$(55,069	)	$(30,541)
Operating loss	—		(1,620	) (3)	—		(1,620	) (3)
Identifiable assets	423,252		393,188	(2)	423,252		393,188	(2)
Capital expenditures	778		816		1,037		1,657
Depreciation and amortization	1,754		1,711		3,453		2,880
Consolidated:
Revenues	$350,599		$337,726		$668,302		$633,916
Operating income	22,807		12,228		32,924		29,593
Identifiable assets	1,224,257		1,062,536	(2)	1,224,257		1,062,536	(2)
Capital expenditures	15,458		18,494		32,774		33,591
Depreciation and amortization	8,629		6,150		16,476		11,393

(1)   Corporate and other revenues are comprised solely of the elimination of intersegment revenues summarized as follows (in millions):

	Quarters Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
Launch Vehicles	$	20.3	$	16.5	$	51.7	$	27.0
Satellites and Space Systems		1.3		1.5		2.5		2.8
Advanced Space Programs		0.5		0.3		0.9		0.7
Total intersegment revenues	$	22.1	$	18.3	$	55.1	$	30.5

(2)    As of December 31, 2010.

(3) The corporate and other operating loss in 2010 is comprised solely of transaction expenses incurred in connection with a business acquisition (see Note 2).

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Research and Development

6 Months Ended

Jun. 30, 2011

Research and Development [Abstract]

Research and Development

(11)  Research and Development

In the first quarter of 2008, the company entered into an agreement with the National Aeronautics and Space Administration ("NASA") to design, build and demonstrate a new space transportation system under a program called Commercial Orbital Transportation Services ("COTS"), for delivering cargo and supplies to the International Space Station.  Under the agreement, as amended, NASA has agreed to pay the company $288 million in cash milestone payments, partially funding Orbital's project costs which are currently estimated to be approximately $445 million.  The company expects to complete this project in the first quarter of 2012.

The COTS agreement is being accounted for as a best-efforts research and development cost-sharing arrangement.  As such, the amounts funded by NASA are recognized proportionally as an offset to the company's COTS project research and development expenses, including associated general and administrative expenses.  As of June 30, 2011 and December 31, 2010, deferred revenue and customer advances on the accompanying balance sheet included $49.9 million and $25.2 million, respectively, of cash received from NASA that had not yet been recorded as an offset to research and development expenses.  The following table summarizes the COTS project research and development expenses incurred and amounts funded by NASA (in millions):

	Second Quarter				First Six Months				Inception
	2011		2010		2011		2010		To Date
Research and development costs incurred (1)	$	36.5	$	38.9	$	78.4	$	67.2	$	337.5
Less - amounts funded by NASA		25.2		18.1		59.3		33.1		211.6
Net research and development expenses	$	11.3	$	20.8	$	19.1	$	34.1	$	125.9

(1) Includes associated general and administrative expenses.

The company is engaged in a major product development program of a medium-capacity rocket named Taurus II.  Approximately $8.2 million and $7.8 million of the company's research and development expenses in the second quarter of 2011 and 2010, respectively, and $15.3 million and $23.1 million in the first six months of 2011 and 2010, respectively, were attributable to the Taurus II program.

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Debt (Details) (USD $)	3 Months Ended			3 Months Ended	6 Months Ended
	Jun. 30, 2011 Convertible Senior Subordinated Notes [Member]	Dec. 31, 2010 Convertible Senior Subordinated Notes [Member]	Dec. 13, 2006 Convertible Senior Subordinated Notes [Member]	Jun. 30, 2011 Credit Facility [Member]	Jun. 30, 2011 Credit Facility [Member]	Dec. 31, 2007 Prior Credit Facility [Member]
Debt Instrument [Line Items]
Face amount			$ 143,800,000			$ 100,000,000
Interest rate (in hundredths)			2.4375%
Maturity date	2027
Net carrying amount	128,300,000	125,500,000
Unamortized debt discount	15,500,000	18,300,000
Initial conversion rate	40.8513
Dollars of debt per conversion rate	1,000
Initial conversion price	$ 24.48
Fair value of debt	149,000,000	150,200,000
Maximum borrowing capacity				300,000,000	300,000,000
Expiration date of credit facility				June 7, 2016
Capacity for the issuance of standby letters of credit				125,000,000	125,000,000
Maximum increase in borrowing capacity				150,000,000	150,000,000
Variable rate basis of loans under the credit facility				LIBOR	LIBOR
Basis spread on variable rate, minimum (in hundredths)				1.75%	1.75%
Basis spread on variable rate, maximum (in hundredths)				2.50%	2.50%
Basis spread on prime base rate, at the company's election, minimum (in hundredths)				0.75%	0.75%
Basis spread on prime base rate, at the company's election, maximum (in hundredths)				1.50%	1.50%
Commitment fee for the unused portion of the credit facility, minimum (in hundredths)				0.30%
Commitment fee for the unused portion of the credit facility, maximum (in hundredths)				0.50%
Letters of credit issued				17,700,000	17,700,000
Amount available for borrowings				$ 282,300,000	$ 282,300,000

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Comprehensive Income

6 Months Ended

Jun. 30, 2011

Comprehensive Income [Abstract]

Comprehensive Income

(9)  Comprehensive Income

Comprehensive income consisted of the following (in thousands):

	Quarters Ended June 30,						Six Months Ended June 30,
	2011			2010			2011			2010
Net income	$	21,217		$	6,345		$	33,552		$	15,613
Unrealized gain (loss) on investments		500			-			1,100			(500	)
Defined benefit plans, net of tax		(155	)		(447	)		(127	)		(281	)
Total comprehensive income	$	21,562		$	5,898		$	34,525		$	14,832

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Business Acquisition and Goodwill

6 Months Ended

Jun. 30, 2011

Business Acquisition and Goodwill [Abstract]

Business Acquisition and Goodwill

(2)  Business Acquisition and Goodwill

On April 2, 2010, the company acquired certain assets and liabilities of the spacecraft development and manufacturing business of General Dynamics Advanced Information Systems, a subsidiary of General Dynamics Corporation (the "Seller"), for $55 million in cash, subject to a potential working capital adjustment.  The company's consolidated financial statements reflect the operations of the acquired business since the date of acquisition.  The company and the Seller are each disputing the other party's claim for a purchase price adjustment based on the calculation of working capital as of the closing date.

The allocation of the purchase price for the tangible and identifiable intangible assets acquired and liabilities assumed was based on their estimated fair values at the date of acquisition using established valuation techniques.  The company may recognize changes to the acquired assets or liabilities as a result of a working capital adjustment or if new information is obtained about facts and circumstances that existed as of the acquisition date.  During the quarter ended June 30, 2011, the company recorded an additional $0.5 million of goodwill related to the update of purchase accounting associated with the acquisition.

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Receivables

6 Months Ended

Jun. 30, 2011

Receivables [Abstract]

Receivables

(5)  Receivables

Receivables consisted of the following (in thousands):

	June 30,		December 31,
	2011		2010
Billed	$	61,774	$	56,035
Unbilled		385,644		270,508
Total	$	447,418	$	326,543

As of June 30, 2011 and December 31, 2010, unbilled receivables included $14.3 million and $14.9 million, respectively, of incentive fees on certain completed satellite contracts that become due incrementally over periods of up to 15 years, subject to the achievement of performance criteria.  In addition, certain satellite contracts require the company to refund cash to the customer if performance criteria, which cover periods of up to 15 years, are not satisfied.  As of June 30, 2011, the company could be required to refund up to approximately $18.2 million to customers if certain completed satellites were to fail to satisfy performance criteria.  Orbital generally procures insurance policies that the company believes would indemnify the company for satellite incentive fees that are not earned and for performance refund obligations.

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Investments (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	$ 9,150		$ 9,150		$ 9,150
Net Unrealized Gain (Loss)	550		550		(550)
Changes in fair value of investments [Roll Forward]
Fair value at beginning of period	9,200	12,600	8,600	13,100
Temporary impairment (charges) credits, net	500	0	1,100	(500)
Fair value at end of period	9,700	12,600	9,700	12,600
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	7,150		7,150		7,150
Net Unrealized Gain (Loss)	(250)		(250)		(450)
Changes in fair value of investments [Roll Forward]
Fair value at beginning of period	6,800	10,500	6,700	10,900
Temporary impairment (charges) credits, net	100	0	200	(400)
Fair value at end of period	6,900	10,500	6,900	10,500
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	2,000		2,000		2,000
Net Unrealized Gain (Loss)	800		800		(100)
Changes in fair value of investments [Roll Forward]
Fair value at beginning of period	2,400	2,100	1,900	2,200
Temporary impairment (charges) credits, net	400	0	900	(100)
Fair value at end of period	2,800	2,100	2,800	2,100
Preferred Stock Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	0		0		0
Changes in fair value of investments [Roll Forward]
Fair value at beginning of period					0
Fair value at end of period	$ 0		$ 0		$ 0

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Inventories

6 Months Ended

Jun. 30, 2011

Inventories [Abstract]

Inventories

(6)  Inventories

Total inventories were $52.5 million at June 30, 2011 and $56.2 million at December 31, 2010.  Substantially all of the company's inventory consisted of component parts, raw materials and milestone payments for future delivery of component parts.  The company had no significant allowances for obsolete inventory as of June 30, 2011 and December 31, 2010.

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Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Numerator
Net income	$ 21,217	$ 6,345	$ 33,552	$ 15,613
Percentage allocated to shareholders (in hundredths)	98.90%	99.20%	98.90%	99.20%
Numerator for basic and diluted earnings per share	$ 20,984	$ 6,294	$ 33,183	$ 15,488
Denominator
Denominator for basic earnings per share - weighted-average shares outstanding (in shares)	58,422,000	57,682,000	58,361,000	57,373,000
Dilutive effect of stock options (in shares)	454,000	667,000	472,000	729,000
Denominator for diluted earnings per share (in shares)	58,876,000	58,349,000	58,833,000	58,102,000
Per share income
Basic (in dollars per share)	$ 0.36	$ 0.11	$ 0.57	$ 0.27
Diluted (in dollars per share)	$ 0.36	$ 0.11	$ 0.56	$ 0.27
Basic weighted-average shares outstanding (in shares)	58,422,000	57,682,000	58,361,000	57,373,000
Basic weighted-average shares outstanding and unvested restricted share units expected to vest (in shares)	59,096,000	58,155,000	59,039,000	57,847,000
Percentage allocated to shareholders (in hundredths)	98.90%	99.20%	98.90%	99.20%
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		100,000		100,000

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Comprehensive Income (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Comprehensive Income [Abstract]
Net income	$ 21,217	$ 6,345	$ 33,552	$ 15,613
Unrealized gain (loss) on investments	500	0	1,100	(500)
Defined benefit plans, net of tax	(155)	(447)	(127)	(281)
Total comprehensive income	$ 21,562	$ 5,898	$ 34,525	$ 14,832

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Inventories (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Inventories [Abstract]
Total inventories	$ 52,531	$ 56,217

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Basis of Presentation (Policies)

6 Months Ended

Jun. 30, 2011

Basis of Presentation [Abstract]

Use Of Estimates

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions, including estimates of future contract costs and earnings.  Such estimates and assumptions affect the reported amounts of assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and earnings during the current reporting period.  Management periodically assesses and evaluates the adequacy and/or deficiency of liabilities recorded for various reserves, contract risks and other uncertainties.  Actual results could differ from these estimates and assumptions.

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Investments

6 Months Ended

Jun. 30, 2011

Investments, Debt and Equity Securities [Abstract]

Investments

(7)  Investments

As of June 30, 2011, the company held investments consisting of three auction-rate debt securities (life insurance company capital reserve funds), an auction-rate equity security (financial guarantee company capital reserve fund) and two preferred stock investments.  These investments are classified as available for sale securities and as non-current assets on the company's balance sheet.  Contractual maturities for the debt securities are 14 years or greater and the remaining securities have no fixed maturity.  The amortized cost and fair value of these investments were as follows (in thousands):

	June 30, 2011							December 31, 2010
	Cost or Amortized Cost		Net Unrealized Gain (Loss)			Fair Value		Cost or Amortized Cost		Net Unrealized Gain (Loss)			Fair Value
Debt	$	7,150	$	(250	)	$	6,900	$	7,150	$	(450	)	$	6,700
Equity(1)		2,000		800			2,800		2,000		(100	)		1,900
Total	$	9,150	$	550		$	9,700	$	9,150	$	(550	)	$	8,600

(1)  As of June 30, 2011 and December 31, 2010, cost and fair value of the two preferred stock investments were $0.

The changes in fair value of the investments were recorded as follows (in thousands):

	Quarters Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
Debt Securities
Fair value at beginning of period	$	6,800	$	10,500	$	6,700	$	10,900
Temporary impairment credits (charges), net		100		-		200		(400	)
Fair value at end of period	$	6,900	$	10,500	$	6,900	$	10,500
Equity Securities
Fair value at beginning of period	$	2,400	$	2,100	$	1,900	$	2,200
Temporary impairment credits (charges), net		400		-		900		(100	)
Fair value at end of period	$	2,800	$	2,100	$	2,800	$	2,100
Total
Fair value at beginning of period	$	9,200	$	12,600	$	8,600	$	13,100
Temporary impairment credits (charges), net		500		-		1,100		(500	)
Fair value at end of period	$	9,700	$	12,600	$	9,700	$	12,600

There was no sale, purchase, issuance, settlement or transfer activity related to these investments during the periods presented.

Auction-rate securities are intended to be structured to provide liquidity through an auction process that resets the applicable interest rate at predetermined calendar intervals.  This mechanism allows existing investors either to roll over or liquidate their holdings by selling such securities at par.  Since the third quarter of 2007 and through June 30, 2011, the auctions, which occur approximately every 28 days for the auction-rate securities held by the company, have not had sufficient buyers to cover investors' sell orders, resulting in unsuccessful auctions.  These unsuccessful auctions result in a resetting of the interest rate paid on the securities until the next auction date, at which time the process is repeated.

The company has estimated the fair value of these securities based on an income approach using a discounted cash flow analysis which considered the following key inputs: (i) the underlying structure of each security; (ii) the present value of future principal and interest payments discounted at rates considered to reflect current market conditions and the relevant risk associated with each security; and (iii) the time horizon until each security will be sold.  The discount rates used in the present value calculations are based on yields on U.S. Treasury securities with similar time horizons plus interest rate risk premiums that are intended to compensate for general market risk and the risk specific to each security.  The risk premiums are based upon current credit default swap pricing market data for similar or related securities or credit spreads for corporate bonds with similar credit ratings and similar maturities.  The discounted cash flow analysis is a Level 3 valuation.

The company records other-than-temporary impairment charges with respect to equity securities based on the company's assessment that it is likely that the fair value of the investment will not fully recover in the foreseeable future given the duration, severity and continuing declining trend of the fair value of the security, as well as the uncertain financial condition and near-term prospects of the issuer.  The company determines other-than-temporary impairment charges for its debt securities based on credit losses.

At this time it is uncertain if or when the liquidity issues relating to these investments will improve, and there can be no assurance that the market for auction-rate securities will stabilize.  The fair value of the auction-rate securities could change significantly in the future and the company may be required to record additional temporary or other-than-temporary impairment charges if there are further reductions in fair value in future periods.

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Receivables (Tables)

6 Months Ended

Jun. 30, 2011

Receivables [Abstract]

Receivables

Receivables consisted of the following (in thousands):

	June 30,		December 31,
	2011		2010
Billed	$	61,774	$	56,035
Unbilled		385,644		270,508
Total	$	447,418	$	326,543

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Receivables (Details) (USD $)	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Receivables [Abstract]
Potential refund if performance criteria are not met	$ 18,200,000
Period of performance criteria (in years)	15Y
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, net	447,418,000	326,543,000
Billed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, net	61,774,000	56,035,000
Unbilled [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, net	385,644,000	270,508,000
Period of incentive fees due (in years)	15Y
Incentive Fees Due Incrementally	$ 14,300,000	$ 14,900,000

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Basis of Presentation

6 Months Ended

Jun. 30, 2011

Basis of Presentation [Abstract]

Basis of Presentation

(1)  Basis of Presentation

Orbital Sciences Corporation (together with its subsidiaries, "Orbital" or the "company"), a Delaware corporation, develops and manufactures small- and medium-class rockets and space systems for commercial, military and civil government customers.

In the opinion of management, the accompanying unaudited interim financial information reflects all adjustments, consisting of normal recurring accruals, necessary for a fair presentation on a going concern basis.  Certain information and disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America ("U.S. GAAP") have been condensed or omitted pursuant to instructions, rules and regulations prescribed by the U.S. Securities and Exchange Commission.  The company believes that the disclosures provided herein are adequate to make the information presented not misleading when these unaudited interim condensed consolidated financial statements are read in conjunction with the audited consolidated financial statements contained in the company's Annual Report on Form 10-K for the year ended December 31, 2010.

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions, including estimates of future contract costs and earnings.  Such estimates and assumptions affect the reported amounts of assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and earnings during the current reporting period.  Management periodically assesses and evaluates the adequacy and/or deficiency of liabilities recorded for various reserves, contract risks and other uncertainties.  Actual results could differ from these estimates and assumptions.

All financial amounts are stated in U.S. dollars unless otherwise indicated.

The company has evaluated subsequent events in accordance with U.S. GAAP.  Management has evaluated the events and transactions that have occurred through the date the financial statements were issued, and noted no items requiring adjustment or disclosure in the financial statements.  Operating results for the quarter ended June 30, 2011 are not necessarily indicative of the results expected for the full year.

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Investments (Tables)

6 Months Ended

Jun. 30, 2011

Investments, Debt and Equity Securities [Abstract]

Amortized Cost and Fair Value of Investments

The amortized cost and fair value of these investments were as follows (in thousands):

	June 30, 2011							December 31, 2010
	Cost or Amortized Cost		Net Unrealized Gain (Loss)			Fair Value		Cost or Amortized Cost		Net Unrealized Gain (Loss)			Fair Value
Debt	$	7,150	$	(250	)	$	6,900	$	7,150	$	(450	)	$	6,700
Equity(1)		2,000		800			2,800		2,000		(100	)		1,900
Total	$	9,150	$	550		$	9,700	$	9,150	$	(550	)	$	8,600

(1)  As of June 30, 2011 and December 31, 2010, cost and fair value of the two preferred stock investments were $0.

Changes in Fair Value of Investments

The changes in fair value of the investments were recorded as follows (in thousands):

	Quarters Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
Debt Securities
Fair value at beginning of period	$	6,800	$	10,500	$	6,700	$	10,900
Temporary impairment credits (charges), net		100		—		200		(400	)
Fair value at end of period	$	6,900	$	10,500	$	6,900	$	10,500
Equity Securities
Fair value at beginning of period	$	2,400	$	2,100	$	1,900	$	2,200
Temporary impairment credits (charges), net		400		—		900		(100	)
Fair value at end of period	$	2,800	$	2,100	$	2,800	$	2,100
Total
Fair value at beginning of period	$	9,200	$	12,600	$	8,600	$	13,100
Temporary impairment credits (charges), net		500		—		1,100		(500	)
Fair value at end of period	$	9,700	$	12,600	$	9,700	$	12,600

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Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2011

Stock-based compensation [Abstract]

Information Related to Stock-Based Compensation Transactions

The following tables summarize information related to the company’s stock-based compensation:

	Restricted Stock Units						Stock Options
				Weighted Average						Weighted Average
	Number of			Measurement			Number of			Exercise
	Units			Date Fair Value			Options			Price
Outstanding at December 31, 2010		684,674			$	16.38		1,226,582			$	6.46
Granted (1)		26,860				17.47		—				—
Exercised		—				—		(135,971	)			4.60
Vested		(35,107	)			16.59		—				—
Forfeited		(8,145	)			16.73		—				—
Expired		—				—		(5,648	)			4.14
Outstanding at June 30, 2011		668,282			$	16.41		1,084,963	(2)		$	6.70

(1)   The fair value of restricted stock unit grants is determined based on the closing market price of Orbital’s common stock on the date of grant.  Such value is recognized as expense over the service period, net of estimated forfeitures.

(2)     The weighted average remaining contractual term is 1.85 years.

	Quarters Ended June 30,
(in millions)	2011		2010
Stock-based compensation expense	$	1.5	$	1.7
Income tax benefit related to stock-based compensation expense		0.5		0.7
Intrinsic value of options exercised computed as the market
price on the exercise date less the price paid to exercise the options		0.5		1.2
Cash received from exercise of options		0.1		2.2
Tax benefit recorded as credits to additional paid-in capital related
to stock-based compensation transactions		0.2		0.4
	Six Months Ended June 30,
(in millions)	2011		2010
Stock-based compensation expense	$	2.9	$	3.5
Income tax benefit related to stock-based compensation expense		0.9		1.4
Intrinsic value of options exercised computed as the market
price on the exercise date less the price paid to exercise the options		1.8		5.4
Cash received from exercise of options		0.6		9.7
Tax benefit recorded as credits to additional paid-in capital related
to stock-based compensation transactions		0.7		2.0

	As of
(in millions)	June 30, 2011
Shares of common stock available for grant under stock-based incentive plans		1.3
Aggregate intrinsic value of restricted stock units that are expected to vest	$	11.3
Unrecognized compensation expense related to non-vested restricted stock units, expected to
be recognized over a weighted-average period of 1.80 years		6.1
Aggregate intrinsic value of stock options outstanding, all fully vested		11.0

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Industry Segment Information

6 Months Ended

Jun. 30, 2011

Industry Segment Information [Abstract]

Industry Segment Information

(3)  Industry Segment Information

Orbital's products and services are grouped into three reportable business segments:  launch vehicles, satellites and space systems and advanced space programs.  Reportable segments are generally organized based upon product lines.  Corporate office transactions that have not been attributed to a particular segment, as well as consolidating eliminations and adjustments, are reported in corporate and other.  The primary products and services from which the company's reportable segments derive revenues are:

. Launch Vehicles - Rockets that are used as small- and medium-class space launch vehicles that place satellites into Earth orbit and escape trajectories, interceptor and target vehicles for missile defense systems and suborbital launch vehicles that place payloads into a variety of high-altitude trajectories.

. Satellites and Space Systems - Small- and medium-class satellites that are used to enable global and regional communications and broadcasting, conduct space-related scientific research, collect imagery and other remotely-sensed data about the Earth, carry out interplanetary and other deep-space exploration missions and demonstrate new space technologies.

. Advanced Space Programs - Human-rated space systems for Earth-orbit and deep-space exploration, and small- and medium-class satellites primarily used for national security space programs and to demonstrate new space technologies.

Intersegment sales are generally negotiated and accounted for under terms and conditions that are similar to other commercial and government contracts.  Substantially all of the company's assets and operations are located within the United States.

The following table presents operating information and identifiable assets by reportable segment (in thousands):

	Quarters Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
Launch Vehicles:
Revenues(1)	$131,367		$95,702		$236,640		$196,044
Operating income	6,870		3,469		1,821		8,000
Identifiable assets	200,116		212,360	(2)	200,116		212,360	(2)
Capital expenditures	10,184		12,209		20,696		22,425
Depreciation and amortization	3,952		1,808		7,272		3,614
Satellites and Space Systems:
Revenues(1)	$138,174		$139,423		$290,833		$239,944
Operating income	8,474		7,512		18,784		15,219
Identifiable assets	293,661		268,804	(2)	293,661		268,804	(2)
Capital expenditures	2,016		1,797		3,845		3,327
Depreciation and amortization	2,805		2,515		5,516		4,780
Advanced Space Programs:
Revenues(1)	$103,188		$120,926		$195,898		$228,469
Operating income	7,463		2,867		12,319		7,994
Identifiable assets	307,228		188,184	(2)	307,228		188,184	(2)
Capital expenditures	2,480		3,672		7,196		6,182
Depreciation and amortization	118		116		235		119
Corporate and Other:
Revenues(1)	$(22,130	)	$(18,325	)	$(55,069	)	$(30,541)
Operating loss	-		(1,620	) (3)	-		(1,620	) (3)
Identifiable assets	423,252		393,188	(2)	423,252		393,188	(2)
Capital expenditures	778		816		1,037		1,657
Depreciation and amortization	1,754		1,711		3,453		2,880
Consolidated:
Revenues	$350,599		$337,726		$668,302		$633,916
Operating income	22,807		12,228		32,924		29,593
Identifiable assets	1,224,257		1,062,536	(2)	1,224,257		1,062,536	(2)
Capital expenditures	15,458		18,494		32,774		33,591
Depreciation and amortization	8,629		6,150		16,476		11,393

(1)   Corporate and other revenues are comprised solely of the elimination of intersegment revenues summarized as follows (in millions):

	Quarters Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
Launch Vehicles	$	20.3	$	16.5	$	51.7	$	27.0
Satellites and Space Systems		1.3		1.5		2.5		2.8
Advanced Space Programs		0.5		0.3		0.9		0.7
Total intersegment revenues	$	22.1	$	18.3	$	55.1	$	30.5

(2)    As of December 31, 2010.

(3) The corporate and other operating loss in 2010 is comprised solely of transaction expenses incurred in connection with a business acquisition (see Note 2).

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Income Taxes

6 Months Ended

Jun. 30, 2011

Income Taxes [Abstract]

Income Taxes

(12)  Income Taxes

The company's effective tax rates were 15.7% and 39.1% for the six months ended June 30, 2011 and 2010, respectively.  The lower tax rate in 2011 primarily resulted from a favorable income tax adjustment of $7.7 million recorded in the second quarter of 2011, pertaining to the company's election to claim extraterritorial income ("ETI") exclusions related to prior-year export activity.  The tax rate in 2011 also includes the effect of the federal research and development tax credit that was reinstated in December 2010.

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Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Stock-based compensation, additional disclosures [Abstract]
Stock-based compensation expense	$ 1.5	$ 1.7	$ 2.9	$ 3.5
Income tax benefit related to stock-based compensation expense	0.5	0.7	0.9	1.4
Tax benefit recorded as credits to additional paid-in capital related to stock-based compensation transactions	0.2	0.4	0.7	2.0
Shares of common stock available for grant under stock-based incentive plans (in shares)	1,300,000		1,300,000
Restricted Stock Units [Member]
Summary of Restricted Stock Units activity [Roll Forward]
Outstanding at beginning of period (in shares)			684,674
Granted (in shares)			26,860
Vested (in shares)			(35,107)
Forfeited (in shares)			(8,145)
Outstanding at end of period (in shares)	668,282		668,282
Weighted Average Measurement Date Fair Value [Abstract]
Outstanding at beginning of period (in dollars per share)			$ 16.38
Granted (in dollars per share)			$ 17.47
Vested (in dollars per share)			$ 16.59
Forfeited (in dollars per share)	$ 16.73		$ 16.73
Outstanding at end of period (in dollars per share)	$ 16.41		$ 16.41
Stock-based compensation, additional disclosures [Abstract]
Aggregate intrinsic value of restricted stock units that are expected to vest	11.3		11.3
Unrecognized compensation expense related to non-vested restricted stock units	6.1		6.1
Unrecognized compensation expense, weighted-average period of recognition (in years)			1.80
Stock Options [Member]
Summary of Stock Option activity [Roll Forward]
Outstanding at beginning of period (in shares)			1,226,582
Exercised (in shares)			(135,971)
Expired (in shares)			(5,648)
Outstanding at end of period (in shares)	1,084,963		1,084,963
Weighted Average Exercise Price [Abstract]
Outstanding at beginning of period (in dollars per share)			$ 6.46
Exercised (in dollars per share)	$ 4.60		$ 4.60
Expired (in dollars per share)	$ 4.14		$ 4.14
Outstanding at end of period (in dollars per share)	$ 6.70		$ 6.70
Stock-based compensation, additional disclosures [Abstract]
Weighted average remaining contractual term (in years)	1.85		1.85
Intrinsic value of options exercised computed as the market price on the exercise date less the price paid to exercise the options	0.5	1.2	1.8	5.4
Cash received from exercise of options	0.1	2.2	0.6	9.7
Aggregate intrinsic value of stock options outstanding, all fully vested	$ 11.0		$ 11.0

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Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2011

Earnings Per Share [Abstract]

Computation of Basic and Diluted Earnings Per Share

The computation of basic and diluted earnings per share ("EPS") is as follows (in thousands, except per share amounts):

			Quarters Ended June 30,						Six Months Ended June 30,
Numerator			2011			2010			2011			2010
		Net income	$	21,217		$	6,345		$	33,552		$	15,613
		Percentage allocated to shareholders (1)		98.9	%		99.2	%		98.9	%		99.2	%
		Numerator for basic and diluted earnings per share	$	20,984		$	6,294		$	33,183		$	15,488
Denominator
		Denominator for basic earnings per share -
		weighted-average shares outstanding		58,422			57,682			58,361			57,373
		Dilutive effect of stock options		454			667			472			729
		Denominator for diluted earnings per share		58,876			58,349			58,833			58,102
Per share income
		Basic	$	0.36		$	0.11		$	0.57		$	0.27
		Diluted		0.36			0.11			0.56			0.27
_________________________
	(1)	Basic weighted-average shares outstanding		58,422			57,682			58,361			57,373
		Basic weighted-average shares outstanding and
		unvested restricted share units expected to vest		59,096			58,155			59,039			57,847
		Percentage allocated to shareholders		98.9	%		99.2	%		98.9	%		99.2	%

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CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 286,742	$ 252,415
Receivables, net	447,418	326,543
Inventories	52,531	56,217
Deferred income taxes, net	34,260	24,348
Other current assets	8,067	18,111
Total current assets	829,018	677,634
Investments	9,700	8,600
Property, plant and equipment, net	249,061	232,706
Goodwill	75,261	74,747
Deferred income taxes, net	33,923	47,806
Other non-current assets	27,294	21,043
Total assets	1,224,257	1,062,536
Current liabilities:
Accounts payable and accrued expenses	298,164	248,835
Deferred revenues and customer advances	183,960	112,182
Total current liabilities	482,124	361,017
Long-term obligations	128,308	125,535
Other non-current liabilities	5,764	7,367
Total liabilities	616,196	493,919
Commitments and contingencies
Stockholders' equity:
Preferred Stock, par value $.01; 10,000,000 shares authorized, none outstanding	0	0
Common Stock, par value $.01; 200,000,000 shares authorized, 58,458,374 and 58,239,875 shares outstanding, respectively	585	582
Additional paid-in capital	562,931	558,015
Accumulated other comprehensive loss	(1,038)	(2,011)
Retained Earnings	45,583	12,031
Total stockholders' equity	608,061	568,617
Total liabilities and stockholders' equity	$ 1,224,257	$ 1,062,536

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Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Jun. 30, 2010
Income Taxes [Abstract]
Effective income tax rate (in hundredths)		15.70%	39.10%
Income tax adjustment	$ 7.7