Artist's concept of a UHF spacecraft in Earth orbit. Photo: Boeing

Boeing has received the final go-ahead to manufacture an eleventh satellite for the U.S. Navy's UHF Follow-On communications satellite constellation, keeping the network working well into this decade.

Known as UHF F-11, the new craft is scheduled for launch on a yet-unselected rocket in 2003 to relay spy satellite photos, intelligence reports and strike orders to U.S. troops around the world.

The clearance to build F-11 extends an original $1.9 billion contract to Boeing to build the previous 10 UHF Follow-On spacecraft, all of which have been launched. The UHF series was first ordered in 1988 as next-generation spacecraft needed to replace aging Navy satellites used to beam military communications.

Like previous Boeing-built UHF spacecraft, F-11 will be based on the proven Boeing 601 series of communications satellites. The new military communications craft will cost the Navy and U.S. taxpayers up to $213 million, depending on which launch service provider and rocket is chosen to handle the task of boosting the near three-ton spacecraft into geostationary transfer orbit.

Lockheed Martin-built Atlas rockets lofted the previous UHF craft.

The original contract for a possible F-11 bird for the UHF constellation originally came in November 1999, but BSS just announced that it received the final approval to build the new spacecraft earlier this week.

Since the implementation of the UHF program, a follow-on system to the Navy's previous satellite communications network, 10 UHF satellites have been launched. All 10 those spacecraft were built by BSS, previously Hughes Space and Communications.

The UHF Follow-On F-10 spacecraft in the factory prior to its launch in 1999 here, UFO F-11 will use the Boeing 601 bus. Photo: Boeing

"Over the life of this highly successful program, the UHF Follow-On payloads have evolved to meet the customer's changing needs, while being contained within the same basic Boeing 601 platform. This building-block approach allowed us to add valuable enhancements to the satellite payloads without a break in production," said Tig H. Krekel, President of BSS. "We take great pride in our role on this program because the UHF mobile service is the backbone of military communications today, supporting warfighters on land, at sea and in the air."

F-11 will not offer the Navy a global broadcast service payload, or GBS, like the last three UHF satellites, the last of which was launched atop an Atlas 2A rocket in November 1999. GBS is similar to the commercially available direct broadcasting service.

In a return to the past, the newest addition to the UHF fleet will offer "battlefield-to-battlefield" connections using an ultra high frequency (UHF) payload, as well as more advanced connectivity through an on-board extremely high frequency, or EHF, antenna. It will also feature enhanced antijam telemetry.

Also, unlike the trio of UHF craft preceding F-11, this future satellite will sport a mass of 3,000 pounds once in its operational orbit. The spacecraft will have a solar panel span of only 60 feet tip-to-tip, while the last three birds spanned 75 feet.

In fact, this new communications satellite will be more like UHF F-7 than its sister-craft.

The new craft will be used to sustain the UHF fleet through 2007 when the next generation of communications satellites will begin taking over.