News From Washington
EMS Technologies Awarded $22 M Contract to Develop AEHF Antenna Subsystems
EMS Technologies Inc. announced that TRW Inc. has selected EMS for a contract valued at approximately $22 M over approximately three years to deliver the beam forming network (BFN) for the first two satellites of the AEHF (Advanced Extremely High Frequency) Project, the US Department of Defense next-generation secure communications satellite constellation.
The BFN is a major component of the nuller subsystem, which provides anti-jam capabilities, a key function of the AEHF network that enables all branches of the US military to communicate in real time around the globe. The Air Force has expressed interest in purchasing three or more payloads to complete the constellation.
EMS' Space & Technology Group in Atlanta is a key subcontractor to the Lockheed Martin/TRW Team. EMS' expertise is in manufacturing key pieces of satellite communications systems, including switching networks, modulators and signal nulling subsystems.
"We are committed to doing our part to ensure our national defense readiness. This initial contract for the AEHF Team is one of several opportunities that EMS will have to contribute to the success of this important defense program," said Al Hansen, president and CEO, EMS Technologies. "We look forward to proving our leadership in delivering critical technologies and products to the next generation of military satellites."
US ARS: Microwave Sense Grain Moisture
Scientists in the Agricultural Research Service (ARS), a branch of the US Department of Agriculture in Athens, GA, have developed a new technique that uses microwaves to determine moisture levels in grain crops.
In the new process, an antenna transmits microwaves into grain, such as corn, wheat, barley or soybeans. The microwaves pass through the grain and are received by another antenna. The changes in the microwaves propagation, as they pass through, are a function of the moisture content in the grain. The new procedure automatically adjusts for the different types of grain.
ARS engineer Stuart O. Nelson, visiting scientist Samir Trabelsi, and retired electronics engineer Andrzej Kraszewski developed the technique at the ARS Quality Assessment Research Unit in Athens.
Grain moisture content is important because the level of water in grain is a key factor in determining when the harvest should occur. If harvesting occurs when moisture levels are too high, the combines can damage the grain in the threshing and shelling processes. If the moisture content is too low, there is risk of damage from chattering and kernel breakage. Moisture information is also essential in determining whether grain can be safely stored without spoilage and in determining the selling price.
Using current technology, a separate calibration must be developed for each kind of grain, and corrections are required for differences in temperature of the grain and its bulk density. In many instances, samples must be collected and tested in handheld moisture testers or taken to grain elevators for more accurate testing. The new technique eliminates the need for multiple calibrations and compensates for grain density and temperature.
The new technique has potential applications for use on combines and on grain handling or conveying equipment and provides for continuous moisture monitoring. Grain farmers and handlers could then have better information for managing their operations. If commercialized, the system is expected to be cost-effective because no other sensor is needed for density, and calibration is simpler.
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US Air Force Launches Lockheed Martin-built Milstar Satellite
A US Air Force Milstar II military communications satellite was launched at Cape Canaveral Air Station, FL, aboard a Titan IVB launch vehicle. The satellite and launch vehicle were built by Lockheed Martin Space Systems Co. at its operations in Sunnyvale, CA, and Denver, CO, respectively.
The satellite, designated Milstar II, is the Defense Department's most technologically advanced telecommunications satellite, and is the second to carry the medium data rate (MDR) payload, which can process data at a speed of 1.5 Mbps. The Air Force transitioned to the Block II configuration with last year's successful launch of the first Milstar II satellite. The Milstar block II system offers a variety of enhanced communications features for the US military, including added security through the use of specially designed antennas and faster data rate transmissions for all users.
Milstar I satellites currently on orbit are equipped with a UHF and low data rate payload, which transmit information at rates between 75 and 2400 bits per second. Lockheed Martin is under contract to provide one more Milstar II spacecraft, which is scheduled to launch later this year.
Milstar's switchboard-in-space concept allows communication links to be established rapidly and is a revolutionary departure from current communications systems. The spacecraft constellation provides protected, global communication links for the joint forces of the US military and can transmit voice, data and imagery in addition to offering video teleconferencing capabilities. This Milstar launch increases the Milstar constellation's capability to provide near-global coverage for the nation's strategic forces, Air Force's space warning assets and operationally deployed military forces.
Space Systems/Loral Receives Firm Orders for XTAR-EUR and SpainSat Satellites
Loral Space & Communications announced that Space Systems/Loral (SS/L) has finalized firm contracts for the construction of two new X-band satellites. XTAR-EUR and SpainSat, to be operated by XTARª and Hisdesat, respectively, will provide leased satellite communications services to the US Department of Defense and affiliated agencies, the Spanish Ministry of Defense and other allied governments.
"The US Government's need for defense satellite communications, growing dramatically in the past decade, has far exceeded its current capabilities," said Bill Wright, president of XTAR. "We expect XTAR-EUR and SpainSat to be the first satellites to answer the call of the US and other governments for additional secure bandwidth and we intend to grow this service into a very successful X-band business."
The XTAR-EUR satellite, to begin service in 2003, will carry 12 wideband high power X-band transponders and operate from an Indian Ocean region orbital slot to be determined by XTAR. XTAR-EUR is designed to operate with existing and planned defense communications terminals around the world.
SS/L will build a second satellite, SpainSat, for Hisdesat. SpainSat will operate 13 specially configured high power transponders, 12 at X-band and one at Ka-band, from its 30° West longitude orbital position. SpainSat is expected to begin operations in 2004.
Hisdesat will lease five of SpainSat's X-band transponders to the Spanish Ministry of Defense, with the remaining eight transponders to be leased by XTAR for defense customers in the US and other allied governments. Together, XTAR-EUR and SpainSat are designed to cover a vast geographic area, including the Americas, the Atlantic Ocean region, Western and Eastern Europe, Africa and the Middle East.
Each spacecraft will provide 1000 MHz of bandwidth for use in defense networks. Both are versions of SS/L's space-proven 1300 satellite platform, which has an excellent record of reliable operation. Both XTAR-EUR and SpainSat have a design service life of 15 years and will carry uniquely configured antennas onboard, providing a combination of fixed and steerable beams to maximize the satellite's flexibility.