DULLES, Va.Sept. 2, 2005--

Company's Transportation Management Systems Division to Supply its OrbCAD Integrated System to Help Manage a Fleet of 55 Public Transit Vehicles

Orbital Sciences Corporation (NYSE:ORB) announced today that its Transportation Management Systems division (Orbital TMS) has been selected by Culver City, California for a $3.5 million contract to provide a SmartBus system for the city's fleet of 55 public transit buses and related vehicles. The Orbital TMS system will provide full fleet management capability for Culver City's "CityBus" system, following a 12-month system implementation process.

Commenting on the benefits of the SmartBus system, Culver City's Deputy Transportation Director, Mr. Art Ida, stated, "The SmartBus system will provide us with an efficient, reliable, and scalable bus fleet management system to better meet the public transit demands of our community. We are excited to be rolling out this technology project for the benefit of our bus operators, supervisors, customer service representatives, and, most of all, the public users of our system for many years to come."

The SmartBus system will come packaged with the company's OrbCAD capabilities for computer-aided dispatch and automated vehicle location services. The system will manage 46 public buses, plus six support vehicles and provide mobile dispatch capability for three supervisor vehicles. The Culver City system will feature automated passenger counting, automated stop announcement and security camera subsystems on all fixed route buses. The OrbCAD in-vehicle electronics suite simplifies operations for the driver, enhances public and driver security and supports real-time decision-making.

Mr. David A. Kachemov, Vice President and General Manager of Orbital's TMS division, said, "We look forward to working with Culver CityBus on this project. Our system is designed to enhance their operations and ultimately benefit the riders who rely on this critical service on a daily basis. The Culver City SmartBus system is an important strategic win for Orbital TMS. We intend to showcase the flexibility of the system to meet the needs of transit agencies of all sizes and to take advantage of the sophisticated set of features that OrbCAD offers."

OrbCAD supports improved voice and data communication as well as the dissemination of information to customers. Situational awareness, responsiveness to incidents, service restoration, and enhanced customer service are benefits that Culver CityBus will realize from their SmartBus system implementation.

About Orbital TMS

Orbital TMS is the country's leading supplier of satellite-based Automatic Vehicle Location (AVL) systems for the expanding Intelligent Transportation Systems market. Orbital's AVL systems are used by 55 transit and state agency customers in the U.S. and internationally, with units installed or scheduled to be installed, on approximately 26,000 vehicles. More information about Orbital TMS can be found at http://www.tms-online.com

About Orbital

Orbital develops and manufactures small space and rocket systems for commercial, military and civil government customers. The company's primary products are satellites and launch vehicles, including low-orbit, geosynchronous and planetary spacecraft for communications, remote sensing, scientific and defense 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 offers space-related technical services to government agencies and develops and builds satellite-based transportation management systems for public transit agencies and private vehicle fleet operators. More information about Orbital Sciences Corporation can be found at http://www.orbital.com

    CONTACT: Orbital Sciences Corporation
             Public and Investor Relations
             Barron Beneski, 703-406-5528

    SOURCE: Orbital Sciences Corporation