Last November 30 marked a milestone for a group of European space agencies and manufacturers. The Silex communication system made its first laser link transmission of an image from one satellite to another. Credit for the achievement was due to a high degree of international cooperation as well as to technical wizardry.

An artist's rendition illustrates how the Artemis satellite, orbiting at more than 19,000 miles, communicates via laser with the Spot 4 satellite, which orbits 517 miles above the Earth's surface.

The Silex system consists of the European Space Agency's Opale terminal on the Artemis satellite, which operates at an altitude of 19,270 miles, and the Pastel terminal on the French Space Agency's Spot 4 satellite, which orbits 517 miles above the Earth's surface. The laser system was designed by both space agencies, the French manufacturer Astrium, and more than 20 European contractors.

The satellite-borne terminals exchanged data for high-definition images of Earth taken by Spot 4 at 50 megabits per second. The Artemis spacecraft then beamed the data to
a receiving station operated by Spot Image in Toulouse in southwestern France over a conventional 20-gigahertz radio link. Spot Image sells digital imagery of the Earth to governments, universities, and private companies for use in oil exploration, agricultural and meteorological studies, municipal construction, and other activities.

The Artemis mission was controlled by a French Space Agency facility in Redu, Belgium, while the satellite's operational control center in Fucino, Italy, was run by the Italian consortium Altel, or Aliena Spazio/Telespazio.

The Silex system captured this image of Lanzarote in the Canary Islands and transmitted it to European receivers for research purposes.

The data relay system allows the Spot satellite more and longer opportunities to transmit imagery, rather than just when it is in the "zone of visibility" of a direct receiving station. This increased contact time between spacecraft and ground stations shortens the time between recording the images and making them available to the customer. The optically based communication system could also benefit satellite-to-satellite communication for spacecraft in low Earth orbit, for geo-stationary satellites, and for deep-space probes.

Spot 4 has been in use since May 1998, producing commercial images for Spot Image Corp. in Reston,
Va., and Spot Image S.A. in Toulouse, France. Spot 4 typically uses a conventional radio link to transmit images from the satellite to receiving stations. The Silex link is still being tested.

According to Bernard Cabrieres, director of satellite and teledetection promotion at the French Space Agency, the two satellites will be functioning together by July 2002.

General Dynamics Electric Boat of Groton, Conn., has purchased four machines from ESAB Cutting Systems of Florence, S.C. The machines are destined for the submarine maker's automated hull fabrication yard in Quonset Point, R.I. The quartet includes a laser marker, plasma bevel cutter, laser cutter, and waterjet bevel cutter.

The four machines will underpin a plate processing system designed to eliminate the need for two-dimensional shop drawings. ESAB product manager Steve Zlotnicki explained that plates marked and labeled by laser will be sent to one of the three cutters, based on the cut quality that is needed. Orientation and weld details will remain inscribed on each part as it moves into fabrication.

Video cameras will monitor cutting and provide information to vision systems. Each machine, controlled by open-architecture CNC, will network to a central operator station. From there, an operator will be able to control the cutting machines as well as cranes and conveyors that are used to move the work about.

Once a cutting cycle has been initiated, a controller takes over. For example, the CNC on the plasma cutter sets current, voltage, speed, standoff, pressure, and height.

A $29 million U.S. Air Force order for wind tunnel drives will increase efficiency of the propulsion wind tunnel at Arnold Engineering and Development Center in Tullahoma, Tenn. ABB's Automation Technology Products division of New Berlin, Wis., will supply two 69,000-hp medium-voltage ac drives in a turnkey installation that includes two 60,000-hp synchronous motors, plus transformers, power converters, switchgear harmonic filters, and controls.

The U.S. Air Force has ordered variable speed drives and motors for its propulsion wind tunnel in Tullahoma, Tenn.

The new drives and motors will replace a pair of 35,000-hp induction motors and their liquid rheostats, which are now used to control speed. The motors will operate in tandem with two 83,000-hp synchronous machines that run only at fixed speed.

About 20 percent of testing takes place in the adjustable speed range. Most of the time, both the adjustable and fixed speed motors run; in those cases, conditions in the tunnel are controlled through stator vanes and bypass valves.

The 83,000-hp machines stand more than 20 feet high. In 1989, ASME designated the propulsion wind tunnel an international historic landmark.

Space restrictions at the General Motors sport utility vehicle assembly plant in Moraine, Ohio, had engineers at Cincinnati-based TKF Inc. thinking outside the box. Make that "thinking outside the circle."

According to TKF chief engineer John Treft, round silos normally used for accumulating tires couldn't fit into the space that GM had allotted them. Instead, TKF designed and built a couple of accumulators shaped as ovals.

Two accumulators bracket the assembly line, Treft explained. One delivers assembled wheels and tires for driver sides; a second brings tires down to passenger sides. A third silo delivers full-size spares upstream of the other two accumulators, at the spot on the assembly line just ahead of where the chassis and bodies marry.

GM needed to stockpile about an hour's worth of tires in the silosÑenough to build 60 autos. To control backpressure from accumulating tires, the silos use pneumatic stops placed every 30 feet or so along the roller conveyor line. A final escapement at the outfeed drops one tire at a time into a tip-up machine that reorients it from flat to upright, readying each tire-wheel assembly for installation on a passing SUV.

Concern about whether the tire assemblies could successfully transition through the oval's tightened bends led TKF engineers to mock up a single curve of track. Assemblies ran through without any hangups, Treft said.

A New Jersey company has developed a product to control "oil mist haze." The haze, which arises when high-speed cutting tools atomize fluid coolants, reduces visibility and creates cleanup problems. Far more important, though, is that it poses a health hazard in the shop.

The Mist Check is designed to clear up oil mist haze emitted from machine tools.

Sternvent Co. of Bogota, N.J., says its Mist Check system collects and filters the mist from the air. According to the company, it is designed to work with both open-style or enclosed metalworking machines. The system uses a blower to keep negative pressure at the source of the mist, which is sucked into a hose and into two filter stages. The first, a wire mesh pre-filter, captures chips or bits of metal. The mesh also collects drops of the mist. The semi-cleaned air then passes into the second stage, a fiberglass filter.

The Mist Check can be used on both water-based and oil-based coolants.

To deal with oil-based coolants, which can produce a bluish smoke that can pass through both standard cleaning stages, the company offers an optional high-efficiency particle air,
or HEPA, filter.

Peter Levitt, product manager, said that Mist Check is 97 percent effective for one-micron-size particles. Systems equipped with the HEPA filter are 99.97 percent effective, he said. The filters are offered in four sizes, with capacities from 1,000 to 6,000 cubic feet per minute.

A manufacturer of water electrolysis systems has designed a prefabricated hydrogen gas station in the dimensions of a 40-foot shipping container.

The manufacturer, Teledyne Energy Systems Inc. of Hunt Valley, Md., said it has shipped one of the new prefab units to a customer overseas, which will use it to cool electric generators. The company said it sees potential markets in various industrial applications and in filling stations for hydrogen-powered vehicles.

According to Teledyne, the station is customizable and can be made available with the capacity to turn out the equivalent of 45 normal cubic meters of H₂ an hour, at a pressure of some 34.5 megapascals. That translates in American units to the amount of hydrogen in 1,500 standard cubic feet, but delivered under 5,000 psi.

The system, called H₂Oasis, is in a prefab housing that includes the needed controls and connections for water and power, a spokesman said.

The H₂Oasis and the company's freestanding electrolysis systems consume in the neighborhood of 5.6 kilowatt-hours of electricity to produce a normal cubic meter of hydrogen.

No one is certain that playing virtual reality computer games can fight real-world motion sickness, say, from the rocking of an actual boat, but a group of British researchers aims to find out.

Motion sickness can be overcome by subjecting a person to real motion at frequent and regular intervals, and VR sickness by getting them used to virtual movement, but a crossover is the subject of study by scientists at Loughborough University in Loughborough, England.

"This phenomenon of the body becoming resistant to motion sickness is called habituation," said Peter Howarth, who is leading the research at the university's department of human sciences. "We've shown in earlier studies that habituation also occurs in virtual environments. If someone is repeatedly exposed to the appearance of motion, they get used to it and no longer feel queasy."

If habituation is transferable to real motion from virtual, play may help those who suffer from motion sickness while traveling, Howarth said.

"It could be that if people play these types of computer games at home and habituate to the appearance of motion, they'll experience less motion sickness in the real world," he said.

The researchers will recruit about 200 volunteers to wear head-mounted displays and play a virtual racing-car game for 20 minutes at a time. Throughout the period, they'll report on how they're feeling.

That data will be compared with statistics on habituation for real motion, for which a large body of information already exists.

"We would propose to habituate our volunteers to the virtual environment and then expose them to real motion to see if they cope better than people who have received no virtual habituation," Howarth said.

The research is being carried out with funding from the Engineering and Physical Sciences Research Council in Swindon, England. The council supports research and related postgraduate training in engineering and the physical sciences.

The U.S. demand for fluid handling pumps will increase over 4 percent per year, to reach $75 billion in 2005, according to a new study conducted by The Freedonia Group Inc., an industrial market research firm in Cleveland. The study predicted that centrifugal pumps will be the most commonly used type because of their wide pressure and load handling capability, and that process manufacturing industries will remain the largest market for pumps.

Sasol Chemical Industries has commissioned Foster Wheeler South Africa Ltd. to deign and build an acrylic acid and acrylates complex in Sasolburg, South Africa. The $20 million facility will produce 80,000 metric tonnes of acrylic acid and their equivalent acrylate products for a joint venture between Sasol and Mitsubishi Chemical Corp.

The drill ship Peregrine III, owned by Transocean Sedco Forex Inc. of Houston, rescued all nine crew members of the survey vessel Aloha, which lost power and foundered approximately 100 miles northeast of Cozumel
last month on a voyage to the site of a bullion wreck.

Flow Science Inc. of Santa Fe, N.M., has released an upgrade to its Flow-3D computational fluid dynamics software. Version 8.0 features new models and improvements designed to increase the software's capabilities.

The Internet-based training company Qwill Ltd. of Norwich, England, has made available a number of training programs for CATIA, the computer-aided design system from Dassault Systemes of Paris, and IBM of Armonk, N.Y. The training programs take place over the Qwill Web site at www.CADutils.com.

Following an audit by the Powermark Corp., the Florida Solar Energy Center of Cocoa, Fla. has been accredited as a certifying laboratory for the rating of photovoltaics. The lab can now certify the performance of PV modules, verify the design of stand-alone systems, and confirm the power rating of grid-connected panels.

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