The communications payload provides Milstar users with bandwidth on demand and the ability to rapidly configure satellite-based networks linking U.S. military forces around the world.

The fifth payload is the first to carry a consolidated agile beam antenna, which merges the functions of five previously separate agile beam antennas into a single, smaller, less costly unit. The antenna's beams constantly scan the visible portions of the Earth's surface, transmitting and receiving signals to and from dispersed users.

"This antenna will dramatically enhance Milstar's mission utility and save millions of dollars over the life of the program," said Wes Bush, vice president and general manager of TRW's Telecommunication Programs Division. "It shows how innovative engineering continues to increase the payload's capabilities while decreasing overall schedule and cost risk."

Bush outlined three major benefits afforded consolidating five antennas into one.

• Improved military effectiveness, provided by improved satellite payload performance. The consolidated antenna improves the payload's "listening" capability by increasing the receive subsystem's sensitivity, allowing the agile beams to detect fainter signals from Earth. The increased sensitivity enables the use of smaller, lighter and less costly user terminals.
• Satellite cost savings, amounting to $1.2 million to the U.S. Air Force versus the build-to-print cost of the previous five-antenna configuration. Those savings include all non-recurring costs of designing the consolidated antenna, building an engineering model and performing qualification testing.

• Dramatic lowering of antenna size and weight, which improves overall satellite performance. The consolidated antenna slices existing agile beam antenna weight by 45% and "footprint" size by 65%. The weight savings may be employed to increase functionality in other parts of the payload or satellite.

Milstar satellites 3 through 6, which are designated Block II satellites, are designed to carry both the LDR payload and a new medium data rate (MDR) payload to expand Milstar's tactical communications capabilities. TRW provides the digital subsystem and antenna subsystems for the MDR payload, which is being integrated for Lockheed Martin Missiles & Space by Hughes Space & Communications Co.

The Department of Defense's Milstar system includes a constellation of ultra-secure communications satellites in geosynchronous orbit, and a family of fixed-site, mobile and man-portable terminals.

Operating primarily in the extremely high frequency (EHF) and super high frequency (SHF) bands, Milstar provides secure, survivable communications among the National Command Authority and Army, Navy and Air Force users anywhere in the world, day or night, under any level of conflict.

Lockheed Martin Missiles & Space, the Milstar space segment prime contractor, designs and integrates the satellite with payloads provided by TRW and Hughes. The Milstar satellites -- autonomous "digital switchboards in space" -- are significant for their onboard processing and switching capabilities, which enable communications on demand to users anywhere, anytime.

MilSpace - SpaceDaily Special Report

Related Links

SPACEDAILY

Pegasus To Launch A Puppie
Vandenberg AFB - May 13, 1999 -
The Terriers satellite, part of NASA's Student Explorer Demonstration Initiative, is scheduled for launch aboard an Orbital Sciences Pegasus XL rocket on Monday, May 17 (PDT).