Orbital Sciences Corporation (NYSE:ORB), one of the world’s leading space technology companies, announced today that the Intelsat 15 (IS-15) satellite, built by the company for Intelsat, Ltd., was successfully launched into orbit aboard a Land Launch Zenit-3 rocket from the Baikonur Cosmodrome in Kazakhstan. The mission, which took place yesterday, November 30, began with the lift-off of the Zenit-3 space launch vehicle at 4:00 p.m. (EST). The satellite separated from the final stage of the rocket approximately six hours and 30 minutes after launch.

Mr. Christopher Richmond, Orbital’s Senior Vice President and head of its communications satellite business unit, said, “Following the excellent launch carried out by the Land Launch Zenit rocket, the several-week in-orbit testing process has now begun. Intelsat and Orbital engineers are now working together to prepare the spacecraft for its introduction into commercial service. We are very pleased that the IS-15 mission is off to such a good start and we look forward to completing the in-orbit testing and turning over another reliable satellite to Intelsat.”

Orbital designed, built and tested the IS-15 spacecraft at the company’s satellite manufacturing facility in Dulles, Virginia. The IS-15 satellite will replace the Intelsat 709 satellite currently positioned at 85 degrees East Longitude. The high power Ku-band payload aboard IS-15 will provide video and data services for the Middle East and Indian Ocean regions as well as Russia. The IS-15 spacecraft is designed to produce 4.6 kW of payload electrical power and features two 2.3 meter dual-grid deployable antennas, as well as one 1.4 meter dual-grid deck-mounted antenna. The satellite is expected to have a useful life of at least 17 years and is part of Intelsat’s 11-satellite launch campaign, the largest in Intelsat’s history.

The IS-15 satellite is one of nine Orbital spacecraft ordered by Intelsat since 2001 that are either now in orbit or in production for upcoming launches. The other satellites are as follows:

* Galaxy 12 and 14, currently in orbit providing C-band digital video programming, high-definition television (HDTV) and other fixed satellite services to the Continental United States, Alaska and Hawaii.

* Galaxy 15, currently in orbit providing services similar to Galaxy 12 and 14 with an additional L-band payload to relay Global Positioning Systems (GPS) navigation data to in-flight aircraft.

* Intelsat 11, a hybrid satellite currently in orbit with a C-band payload serving the continental United States, Mexico and South America, and a Ku-band payload serving DirecTV’s downlink for Brazil, with additional spot coverage.

* Horizons-2, currently in orbit for a joint venture between Intelsat and SKY Perfect JSAT of Japan, to meet the growing demand for Ku-band communications in North America.

* Intelsat 16, a high-power Ku-band satellite to provide direct-to-home TV services to Latin and South America. The satellite is nearing completion and is schedule to be shipped to the launch site in approximately one month.

* Intelsat 18, a hybrid C- and Ku-band satellite now in production to provide services to East Asia, the Pacific, French Polynesia and the United States scheduled for delivery in 2010.

* New Dawn, a hybrid C- and Ku-band satellite now in production to provide services to Europe, Middle East, North Africa and Sub-Saharan regions scheduled for delivery in 2010.

Orbital’s highly successful geosynchronous Earth orbit (GEO) communications satellites are based on the company’s STARTM spacecraft platform, which is able to accommodate all types of commercial communications payloads and is compatible will all major commercial launchers. The company’s STAR product line includes the STAR 2.4 design, which is optimized for smaller satellite missions, generating up to 5.0 kW of payload power. Orbital has also developed the higher-power STAR 2.7 spacecraft design, delivering the next increment of payload power for applications between 5.0 and 7.5 kW, allowing Orbital to offer its innovative and reliable satellite design to the medium-class of communications satellites.

About Intelsat

Intelsat is the leading provider of fixed satellite services worldwide. For 45 years, Intelsat has been delivering information and entertainment for many of the world’s leading media and network companies, multinational corporations, Internet service providers and governmental agencies. Intelsat’s satellite, teleport and fiber infrastructure is unmatched in the industry, setting the standard for transmissions of video, data and voice services.

About Orbital

Orbital develops and manufactures small- and medium-class rockets and space systems for commercial, military and civil government customers. The company’s primary products are satellites and launch vehicles, including low-Earth orbit, geosynchronous-Earth orbit and planetary spacecraft for communications, remote sensing, scientific and defense missions; human-rated space systems for Earth-orbit, lunar and other missions; ground- and air-launched rockets that deliver satellites into orbit; and missile defense systems that are used as interceptor and target vehicles. Orbital also provides satellite subsystems and space-related technical services to government agencies and laboratories. More information about Orbital can be found at http://www.orbital.com

Note to Editors: A high-resolution image of the IS-15 satellite is available on Orbital’s web site at: http://www.orbital.com/NewsInfo/ImagesMultimedia/Images/SatelliteSpaceSystems