This document provides an overview of Orbital Sciences Corporation for investors and analysts. Some key points: - Orbital is a leading developer of small and medium-sized space systems, with over 1,050 satellites and launch vehicles built for commercial, government, and civil customers. - The company has a diversified customer base including commercial, DoD, NASA and other agencies. It has three business segments: satellites and space systems, launch vehicles, and advanced space programs. - Orbital has a large contract backlog of $4.7 billion providing high revenue visibility through 2016. It has a conservative balance sheet and strong liquidity. - For 2013, the company reported revenues of $1.

1. An Introduction to Orbital Sciences Corporation Presentation to Investors and Analysts
December 2014
Investors - Dec2014 1

2. Orbital’s Investor Contacts
Investors - Dec2014
David W. Thompson Chairman and Chief Executive Officer 703-406-5500 dwt@orbital.com
Garrett E. Pierce Vice Chairman and Chief Financial Officer 703-406-5676 pierce.garrett@orbital.com
Barron S. Beneski Vice President, Public and Investor Relations 703-406-5528 beneski.barron@orbital.com
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3. Investors - Dec2014
Safe Harbor Statement 3
Certain Material in This Presentation Contains “Forward-Looking Statements” As Defined in the Private Securities Litigation Reform Act of 1995 and Section 21E of the Securities Exchange Act of 1934. These Forward-Looking Statements Include, But Are Not Limited to, Those Related to Our Financial Outlook, Liquidity, Goals, Business Strategy, Projected Plans and Objectives of Management for Future Operating Results, and Forecasts of Future Events. These Statements Can Be Identified By the Fact That They Do Not Relate Strictly to Historical or Current Facts. Forward-Looking Statements Often Include the Words “Anticipate,” “Forecast,” “Expect,” “Believe,” “Should,” “Intend,” “Plan” and Words of Similar Substance. Such Forward- Looking Statements Are Subject to Risks, Trends and Uncertainties That Could Cause the Actual Results or Performance of the Company to Be Materially Different From the Forward-Looking Statement. Such Forward-Looking Statements Are Subject to Risks, Trends and Uncertainties That Could Cause the Actual Results or Performance of the Company to Be Materially Different From the Forward-Looking Statement. Uncertainty Surrounding Factors Such As Reductions or Changes in NASA or U.S. Government Military Spending, Timing of Payments and Budgetary Policies, Including Impacts of Sequestration Under the Budget Control Act of 2011, and Sourcing Strategies; Intense Competition; Increases in Costs, Which the Business May Not Be Able to React to Due to the Nature of U.S. Government Contracts; Changes in Cost and Revenue Estimates and/or Timing of Programs; the Potential Termination of U.S. Government Contracts and the Potential Inability to Recover Termination Costs; Greater Risk Associated With International Business, Including Foreign Currency Exchange Rates and Fluctuations in Those Rates; Other Risks Associated With U.S. Government Contracts That Might Expose Orbital to Adverse Consequences; Government Investigations; Security Threats, Including Cybersecurity and Other Industrial and Physical Security Threats, and Other Disruptions; Changes in Domestic and Global Economic Conditions and Unstable Geopolitical Conditions, Including in Russia and Ukraine; Supply, Availability, and Costs of Raw Materials and Components, Including Commodity Price Fluctuations; Government Laws and Other Rules and Regulations Applicable to Orbital, Such As Procurement and Import- Export Control; Development of Key Technologies and Retention of a Qualified Workforce; Impacts of Financial Market Disruptions or Volatility to Customers and Vendors; Unanticipated Changes in the Tax Provision or Exposure to Additional Tax Liabilities; and the Costs and Ultimate Outcome of Litigation Matters and Other Legal Proceedings May Materially Impact Orbital's Actual Financial and Operational Results. Other Risks, Uncertainties and Factors Are Described in the Company’s SEC Filings, Including the Annual Report on Form 10-K. We Are Under No Obligation to, and Expressly Disclaim Any Obligation or Undertaking to Update or Alter Any Forward-Looking Statement, Whether As a Result of New Information, Subsequent Events or Otherwise, Except As Required By Law.

4. Investors - Dec2014
Orbital Overview

Leading Developer and Manufacturer of Small- and Medium-Class Space Systems

Three-Decade Record of Reliable, Rapid and Affordable Development and Production

Serving Customers in Commercial, National Security and Civil Government Markets

Over 1,050 Satellites and Launch Vehicles Built or On Contract for Customers

219 Satellites and Space Systems
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179 Space and Strategic Launch Vehicles

674 Target Vehicles and Research Rockets

3,400 Employees and 1.6 Million Square Feet of State-of-the-Art Facilities

$4.7 Billion Total Contract Backlog With Premier Customers

2013 Revenues of Approximately $1.4 Million

Conservative Balance Sheet With Strong Liquidity 4

5. Investors - Dec2014
Orbital’s Strategy for Value Creation

Establish and Maintain Leading Positions in Markets for Smaller Space Systems

Focus on Growing Niches Not Well Served By Larger Aerospace Companies

Provide Highly-Reliable Space Systems on Fast Schedules and at Affordable Prices

Grow in Core Markets While Expanding Into Closely Adjacent Areas
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Communications Satellites  Human Space Programs
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Space and Earth Science Programs  Military and Intelligence Space Systems
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Missile Defense Systems  Strategic and Tactical Missiles

Build Shareholder Value Through Solid Execution, Disciplined Resource Allocation and Strong Corporate Governance
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Constantly Improve Engineering Efficiency and Manufacturing Productivity
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Deploy Excess Cash to Enhance Financial Returns and Strategic Flexibility
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Maintain Superior Governance Practices and Transparent Financial Reporting 5
Historical Core Markets
Newer Adjacent Markets

6. Commercial & International Customers
Department of Defense & Intelligence Agencies
NASA, Other Civilian Agencies & Universities
40%
25%
35%
Revenues by Customer Type
Well-Balanced Multi-Market Customer Base
Investors - Dec2014
6

7. Investors - Dec2014
40%
30%
30%
Revenues By Business Segment
Satellites and Space Systems
Launch Vehicles
Advanced Space Programs
Complementary Business Segments
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8. Space Launch Vehicles
Targets and Research Rockets
Interceptor Launch Vehicles
Launch Vehicles Segment

In the Last 32 Years, the Company Has Developed and Built, or Is Now Under Contract to Produce, 849 Launch Vehicles and Research Rockets
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672 Launch Vehicles and Research Rockets Built and Delivered From 1982 to 2013
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177 Additional Vehicles Under Contract for 2014 to 2018 Deliveries

Launch Vehicles Are Fully Developed and In Production
Investors - Dec2014
8

9. Scientific Satellites
Communications Satellites
Space Technical Services

In the Last 32 Years, the Company Has Developed and Built, or Is Now Under Contract to Produce, 161 Commercial and Scientific Satellites and Related Space Systems
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150 Satellites and Major Systems Completed and Delivered From 1982 to 2013

11 Additional Satellites Under Contract for 2014 to 2018 Deliveries
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Primary Satellite Product Lines Are Fully Developed and In Production; Several Product Extensions In R&D for 2014-2015 Introductions
Satellites and Space Systems Segment Investors - Dec2014
9

10. Investors - Dec2014

In the Last 32 Years, the Company Has Developed and Built, or Is Now Under Contract to Produce, 62 Advanced Space Systems for Human Space Flight, National Security and Other Applications
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46 Advanced Systems Completed and Delivered From 1982 to 2013

16 Advanced Systems Under Contract for 2014 to 2018 Deliveries
New Human Space System (Cygnus) Completed R&D in 2013; Various Defense and Commercial R&D and Production Programs Underway
Human Space Systems
National Security Satellites
Advanced Space Programs Segment 10
Advanced Flight Systems

11. 53%
23%
24%
46%
32%
22%
Large Contract Backlog… High Revenue Visibility
11
Investors - Dec2014

Total Contract Backlog Worth ∼$4.7 Billion as of September 30, 2014

Firm Backlog ∼$2.3 Billion

Option Backlog ∼$2.4 Billion

Backlog Provides Excellent Visibility to Near-Term Revenue Growth

95% of 2014 Revenue
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80% of 2015 Revenue

50% of 2016 Revenue

About 50% of Total Backlog Scheduled for Delivery Through End of 2016
Firm Backlog ∼$2.3 Billion
Total Backlog ∼$4.7 Billion
Launch Vehicles
Satellites and Space Systems
Business Segments
About 65% Total Revenue Coverage For 2014-2016
Advanced Space Programs

12. Revenue $1,437 Million $1,365 Million $980 Million
EBITDA Margin(1) 10.4% 11.4% 11.5%
Operating Margin 7.8% 8.3% 8.3%
Earnings per Share(2) $1.08 $1.15 $0.95
Free Cash Flow(1) ($34 Million) $17 Million $166 Million
Investors - Dec2014
(1)
Non-GAAP Financial Measure, See Appendix A
(2)
EPS in 2012 and 2013 Have Been Adjusted for Significant Nonrecurring Transactions, See Appendix A
(3)
2014 YTD Results Adjusted to Exclude Merger Transaction Costs
2013 Results
2014 YTD (9/30/14)(3)
2012 Results
Financial Results Summary
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13. Balance Sheet Summary
Cash and Market Securities $427M
Other Current Assets 606M
Property and Equipment 232M
Goodwill 71M
Other Assets 14M
Total Assets $1,350M
Tax Information
Tax Credit Carryforwards $10M
Credit Facility Data
Revolving Credit Facility $300M
Short-Term Debt $8M
Other Current Liabilities 302M
Long-Term Debt 129M
Other Non-Current Liabilities 59M
Stockholders’ Equity 852M
Total Liabilities & Equity $1,350M
Outstanding Shares
Basic Weighted Average Shares 60.8M
Diluted Weighted Average Shares 61.0M
Corporate Credit Ratings
Standard & Poors – BB+
Moody’s – Ba1 Investors - Dec2014
Balance Sheet Information (As of September 2014)
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14. Investors - Dec2014
Orbital Go-Forward Plan for CRS and Antares

Primary Objectives

Fulfill All Commitments to NASA for ISS Cargo Delivery by End of 2016
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Accelerate Antares Propulsion System Upgrade to Improve Reliability and Performance

Approach

Employ the Inherent Flexibility of Cygnus Cargo Spacecraft to Carry Heavier Loads and Be Launched on Third-Party Rockets to Consolidate 5 Previously Planned CRS Missions Into 4 Missions

Purchase 1 or 2 Third-Party Rockets from U.S. and/or European Suppliers for Cygnus Launches in 2015 and Possibly Early 2016

Complete Current CRS Contract With 2 or 3 Upgraded Antares Launches from Wallops Island in 2016

Expected Consequences

All Required CRS Cargo Deliveries Accomplished at No Cost Increase to NASA and Relatively Minor Schedule Adjustments

No Material Adverse Financial Impacts to Orbital in 2015 or Future Years
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15. Investors - Dec2014
Key Investment Highlights

Market Leader in Small- and Medium-Class Satellites and Rockets

Strong Industry Fundamentals and Solid Growth Outlook

Premier Customer Relationships and Large Contract Backlog

Unmatched Product Reliability and Affordability, Substantial R&D Investment

Proven Management Team, Technical Staff and Operating Systems

Conservative Capitalization With Strong Liquidity and Increasing Cash Flow

Commitment to Shareholder Value Increases in 2014 and Beyond 15

16. Investors - Dec2014
Analyst Firm E-mail Phone # Rating Howard Rubel Jefferies & Company hrubel@jefferies.com 212-284-2129 Buy Michael Ciarmoli KeyBanc Capital Markets mciarmoli@keybanccm.com 610-260-6046 Hold Chris Quilty Raymond James chris.quilty@raymondjames.com 727-567-2602 Buy Joseph DeNardi Stifel Nicolaus Weisel denardij@stifel.com 443-224-1358 Buy Gary Liebowitz Wells Fargo Securities gary.liebowitz@wachovia.com 212-214-5055 Buy
Current Equity Research Analysts
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17. Investors - Dec2014
Appendix A: Non-GAAP Financial Measures

EBITDA margin is defined as earnings before interest (including interest expense, interest income and other income and expense), taxes, depreciation and amortization and merger transaction costs divided by revenues. The most comparable GAAP financial measure to EBITDA is income from operations. Management believes that EBITDA and EBITDA margin are useful for investors because they offer a perspective on the company’s ability to generate cash from its operations.

Free cash flow is defined as Generally Accepted Accounting Principles (GAAP) net cash provided by (used in) operating activities (the most directly comparable GAAP financial measure) less capital expenditures for property, plant and equipment plus net proceeds from disposition of property. Management believes that the company’s presentation of free cash flow is useful because it provides investors with an important perspective on the company’s liquidity, financial flexibility and ability to fund operations and service debt.

Reconciliations of EBITDA and Free Cash Flow are shown below. Orbital does not intend for this information to be considered in isolation or as a substitute for the related GAAP measures. Other companies may define these measures differently. 17
Full-Year 2012 ($ Millions) Full-Year 2013 ($ Millions) YTD 2014 (9/30/14) ($ Millions) Income from Operations $112.6 $113.5 $81.3(1) Depreciation Expense 37.3 41.5 31.7 EBITDA $149.9 $155.0 $113.0 Net Cash Provided By (Used In) Operating Activities $ (7.7) $52.6 $180.4 Capital Expenditures (52.2) (35.6) (24.8) Net Proceeds from Sale of Property 25.6 - 10.0 Free Cash Flow $(34.3) $17.0 $165.6 (1) Adjusted to Exclude Merger Transaction Costs of $9.8 Million

18. Appendix A (Cont’d): Non-GAAP Financial Measures

Adjusted net income is defined as GAAP net income adjusted to exclude merger transaction costs, a non- operating charge pertaining to the write off of an option payment in connection with a business agreement that was terminated in the fourth quarter of 2013, a gain on the sale of investments, debt extinguishment expense and favorable income tax adjustments pertaining to extraterritorial income exclusions. Adjusted diluted earnings per share is equal to adjusted net income divided by diluted shares. These measures are provided so investors can more easily compare current and prior period results without the impact of significant nonrecurring charges and adjustments. The reconciliation of GAAP net income to adjusted net income is as follows: Investors - Dec2014 18
Full-Year 2012 ($ Millions) Full-Year 2013 ($ Millions) YTD 2014 (9/30/14) ($ Millions) GAAP Net Income $61.0 $68.4 $51.5 Adjustments, Net of Tax: Merger Transaction Costs - - 6.3 Business Agreement Termination Charge - 6.1 - Gain on Sale of Investments - (3.7) - Debt Extinguishment Expense 6.3 - - ETI Tax Adjustments (1) (2.8) (1.1) - Adjusted Net Income $64.5 $69.7 $57.8 GAAP Diluted Earnings Per Share $1.02 $1.13 $0.85 Adjusted Diluted Earnings Per Share $1.08 $1.15 $0.95 ___________________ (1) These favorable income tax adjustments pertain to extraterritorial income (ETI) exclusions