DULLES, Va.July 15, 2005--Orbital Sciences Corporation (NYSE:ORB) today announced the recipients of the company's launch vehicle systems Supplier Achievement Awards. Orbital's Launch Systems Group (LSG), which designs, develops, manufactures and operates a wide variety of rockets for space launch missions and missile defense applications, recognized three companies and one individual for outstanding contributions to Orbital-managed programs for military, civil government, commercial and international customers.

This award and recognition process is a part of a supplier development initiative that includes award selection based on a combination of qualitative and quantitative analyses performed by LSG's integrated product teams. An innovative aspect to the selection process is the supplier feedback loop, which views performance through a supply chain continuum, independent of customer and/or supplier distinctions. The process identifies strengths and weaknesses in the supply chain, from the flow-down of customer requirements to the delivery of finished goods and services. The primary objective of the award program is to forge strong partnerships between Orbital and its suppliers to ensure the highest quality and timely delivery of launch vehicle components and subsystems.

    Orbital recognized the following companies and program manager:

HONEYWELL DEFENSE AND SPACE SYSTEMS             SYSTEMS SUPPLIER AWARD
Clearwater, Florida

Honeywell builds the Space Integrated GPS/INS (SIGI) navigation system
that is integrated into virtually all of Orbital's rockets and
missiles, which continue to build on a demonstrated history of
reliability and accuracy. The Honeywell team at Clearwater, Florida
was selected for this award based on its mission success in Orbital
products, technical expertise and excellent on-time delivery.


MICRO POWER ELECTRONICS, INC.                 COMPONENT SUPPLIER AWARD
Hillsboro, Oregon

Micro Power supplies battery packs for Orbital's launch vehicle
systems. Micro Power achieved the Component Supplier Award based on
its outstanding on-time delivery and focus on customer service. This
is the third award Micro Power has received from Orbital over the past
several years. In 2002, Micro Power was recognized with the Extra Mile
Award for benchmark service and support and, in 2003, received
Orbital's Gold Award for Excellence.


PACIFIC SCIENTIFIC ENERGETIC                 GOLD AWARD FOR EXCELLENCE
MATERIALS COMPANY
Valencia, California

Pacific Scientific Energetic Materials Company at Valencia
manufactures the safe and arms system that is used by many of
Orbital's rockets and missiles. Orbital recognized the Pacific
Scientific team for its flexibility and willingness to support
last-minute customer requests, as well as consistently delivering
products that have demonstrated solid mission success.


ENSIGN-BICKFORD AEROSPACE                                "STARS" AWARD
AND DEFENSE COMPANY
MARY REINERT
Simsbury, Connecticut

Ensign-Bickford's Mary Reinert has demonstrated a long and consistent
history of excellent programmatic leadership on multiple Orbital
products, projects and missions. Orbital is pleased to recognize Ms.
Reinert for her ongoing contributions to the company's focus on
supplier quality and responsiveness.

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.


    CONTACT: Orbital Sciences Corporation
             Barron Beneski, 703-406-5528
             Beneski.barron@orbital.com

    SOURCE: Orbital Sciences Corporation