Engineering News 8136

Dream of flight lands home

Santa Clara, CA-A helicopter, for all of its features and applications, can cost up to $1,000,000 and often $500/hour to operate. Now, engineers are bringing this technology into more common consumer hands. The SoloTrek(TM) Exo-Skelitor Flying Vehicle (XFV(TM)) from Millennium Jet harnesses many capabilities of a helicopter, yet will be affordable to own at a speculated price tag of less than $100,000, and cost only 5% of a helicopter's cost to operate. And, it can land on a site the size of a dining room table. The vehicle transports an individual in a standing position for up to 1 1/2 hours before refueling and will travel up to 80 mph.

SoloTrek XFV is actually an advanced-technology piston-engine aircraft that uses a 2-cycle engine. This 4-cylinder powerplant produces 130 hp, while using regular unleaded gasoline. In addition to being fuel efficient, the engine is environmentally friendly with low emissions, the company says.

The 2-cycle engine eliminates moving parts prone to catastrophic failure commonly found in a 4-cycle regime of automobiles and aircraft. Such parts include intake and exhaust valves, pushrods, valve lifters, camshafts, timing belts/chains, and oil pumps.

A large reserve of excess power allows the aircraft to normally operate at 50 to 60% of its installed power, ensuring the engine is not overworked and increasing overall efficiency and reducing noise. And, it keeps critical operating parameters like temperature, vibration, and mechanical stress at levels below those recommended by the engine manufacturer.

Authorized personnel can operate SoloTrek XFV, which is enabled after a retinal eye-exam security system that is part of the machine's head-up display. The vehicle will not take off unless the operator has programmed in his/her correct weight. SoloTrek XFV's ballistic automatically deployable parachute system provides an additional level of safety when operating at altitudes greater than 100 ft above the ground.

The project's chief engineer, Robert W. Bulaga, has worked at McDonnell Douglas, where he served as the leader of its National AeroSpace Plane (NASP) vehicle performance team. Bulaga helped create weapon carriage methods and flight profiles that increased the range of the F-15E by more than 40%. And, he designed a ducted prop drive for a competition car that achieved more than 700 mpg. The ducted prop is the basis for the personal flying machine.

"SoloTrek XFV will become an essential tool in a variety of fields," explains Michael Moshier, founder and CEO of Millenium Jet. Previously recognized for earlier VTOL aircraft designs, Moshier is a former Navy jet combat pilot. "Planet-wide applications are vast, including uses in search and rescue, police departments, disaster response, recreation, commuting, and developing countries."

For more information on developments and an upcoming newsletter on the challenges the engineering team addressed, visit www.solotrek.com

Optical encoder aims for the stars

If you've ever gone out stargazing with a telescope, you know that pointing it on the area that you want to observe requires patience and precision. Now, imagine accomplishing that same task with a multi-ton telescope 8 m in diameter, and you have an idea of the magnitude of the challenge facing a new optical encoder.

A pair of such 8m-diameter behemoths is being outfitted with Heidenhain ERA 780/880 tape encoders. The giant observing tools are being installed on mountain tops in Hawaii and Chile to provide astronomers with clear views of the night skies in both northern and southern hemispheres. Installation will be completed by next year.

The ERA 780/880 is an optical system based on an incremental linear encoder with a 40- micron grating deposited on a steel tape. The tape is used in conjunction with a non-contact sliding optical head that generates Moire fringe patterns as it moves. An optical sensor counts the fringes and calculates the precise length of travel. The encoders are specifically designed for any rotational encoding where large through-holes prevent on-axis encoders from being attached, such as rotary tables and rotating drums, as well as telescopes.

The encoder is used to control both azimuth (horizontal of rotation) and elevation angles of the telescope. For azimuth control, the encoding tape is stretched tightly around the circumference of a 9.5-m-diameter mounting ring. Four read heads are used, in diametrically opposing pairs, so that readings can be averaged and to provide a degree of redundancy.

For elevation control, two 8.5m tapes are mounted on segments positioned on either side of the principal axis, with a reading head on each tape.

Heidenhain uses a manufacturing process that enables the tapes to be produced as a single length, with no joints, thus assuring linearity of the measurements.

Astronauts' treadmill eliminates bad vibes

Houston, TX-Damon C. Smith, a scientist at Lockheed Martin Engineering, has spent much of his career figuring out ways to help astronauts exercise in space. His latest work is an isolation/stabilization system for a treadmill for the new orbiting International Space Station.

Called TVIS (for Treadmill with Vibration Isolation and Stabilization), it differs from previous space-based treadmills in one very significant way: Rather than being hard-mounted to the floor, it is tethered by flexible wire ropes. "We had to make the treadmill free-floating, because even a small force pushing against the space station creates a vibration problem. Driven into oscillation, components like solar panels are going to be flapping around like butterfly wings," explains Smith.

Figuring out how to stabilize the 900-lb, floating treadmill was a major challenge, involving the use of both a flywheel to resist roll and a linear stabilization control system to protect against linear translation and pitch. Its design is based on a systematic way of producing an equal and opposite inertial force to the footfall force of a runner coupled to the treadmill via a harness and spring-loaded cables.

It consists of four linear stabilizers located at each of the corners of the treadmill's frame. Each stabilizer contains a 60-lb block of stainless steel connected to the housing by a linear bearing and driven by a Normag linear motor. Springs, which lower the average power requirement of the motor by a factor of ten, are connected to the mass and tuned so the mass wants to move at a frequency close to the runner's pace and counteract the footfall force.

"We had to have an almost instantaneous response time with high frequency and high velocity," says Smith. "And linear motors were the natural choice for this application."

Fasten your seatbelts

Ft. Collins, CO-Turbulence is the leading cause of injuries on airliners. In fact, U.S. airlines figure it costs them at least $100 million a year in disrupted operations.

Using radar systems onboard three aircraft, along with ground-based radar, a team of government and industry researchers recently collected atmospheric data to gain a better understanding of turbulent storm activity and determine if airborne Doppler radar could reliably detect it. NASA's Aviation Safety Program is leading an effort to design on-board detection and warning systems, improve turbulence forecasting, and minimize turbulence effects.

The National Center for Atmospheric Research, Colorado State University, the National Science Foundation, and the South Dakota School of Mines and Technology are partners in the NASA Langley Research Center turbulence research project. Also on the team are airborne weather radar manufacturers Allied Signal Aerospace and Rockwell Collins, who flew two chase planes. Both were equipped with modern Doppler radar and followed an armored T-28 trainer into stormy weather between Fort Collins, CO and Cheyenne, WY to collect data. Atmospheric information from weather balloons and on-ground Doppler radar systems was also collected. The specially equipped T-28 recorded physical movement and acceleration data experienced while flying through storms and that information was compared with airborne and on ground radar data.

Bill Bresley, project manager with Allied Signal Aerospace (Redmond, WA) says Allied Signal's aim is to develop software to recognize turbulence that occurs at cruise altitudes. This software will run on windshear detection radar hardware already on-board, to be displayed on the pilot's weather radar screen. The company hopes to certify the new algorithms next summer.

Composite adds new life to aircraft

Warrendale, PA-Ever been on a commercial airplane where the cabin looks shoddy? Does this make you wonder if the airline's total maintenance program leaves something to be desired?

The fact is that an aircraft that is well cared for can justifiably relieve passengers' fears about the safety of the plane. It's also the reason that Magee Plastics Co., when it found the paint finish on the window bezel and track assembly it makes for Boeing 737 and 757 aircraft did not stand up to repeated handling, turned to a different material solution. Instead of a paint finish, the company decided to injection mold the assembly.

The window bezel and track assembly consist of two componentsan inner window frame and a guide track for the window shade. Because aircraft parts are highly regulated, the materials used for the injection-molded parts had to meet very exact specifications, including fire resistance. The material selected: Colorcomp^(R) Bayblend FR 2010 composite from LNP Engineering Plastics (Exton, PA).

Even though the material underwent extensive tests before its selection, Magee experienced some difficulty filling out and getting a good surface appearance on the part. The problem: the long flow length of the part. "It's a very thin section that requires excessive heat," explains Don Bergstrom, special projects engineer at Magee. "The high temperatures helped the material flow easier as it thinned, but we were concerned about the detrimental effect on the performance of the plastic."

LNP engineers suggested using the company's Exceptional Process (EP) technology to improve the molding. "By using the additive, we could now fill the part out much easier, at lower pressures," Bergstrom notes. "This enabled us to reduce the cycle time and achieve a better appearance of the finished part."

How well did the material work in the window application? "Colorcomp gives us the structural integrity needed for the part," Bergstrom reports. "And it meets all our requirements for fire resistance and UV stabilization."

LNP also provided a critical color match for the part. "Not having to paint the part is a big cost savings," says Bergstrom. "Our tests confirmed that the addition of color and the EP additive had no detrimental effect on the strength of the material."

Low-cost CAD spurs spectrometer design

Greenbelt, MD At first glance, one might not think that an engineer responsible for development of a mass spectrometer for NASA would have anything to do with in an inexpensive CAD system (under $600). Especially when engineers traditionally use detailed mathematical calculations to design the instruments. But Fred Herrero, technical lead in the Space Technology Integration Office at the NASA Goddard Spaceflight Center, decided to try a non-traditional tact. Instead of equations, Herrero wanted to work with pure geometry. "It's much easier to think geometrically than in equations," Herrero says.

He wanted to find a magnetic-sector geometry that could differentiate a wide range of ion masses. Using Diehl Graphsoft's (Columbia, MD) VectorWorks, a CAD program that simplifies the definition of complex geometry, Herrero developed a miniaturized mass spectrometer the first capable of resolving a wide range of masses with a package that can be as small as a 1 3 2 3 0.75 in.

Herrero conceived the spectrometer design in a graphical manner by manipulating lines and arcs in a CAD program. "The intuitiveness of the VectorWorks program allowed me to create, for example, lines tangent to arcs simply by moving the cursor near the arc and clicking on the tangent label that appears on the screen," he says.

Herrero also used VectorWorks to simulate ions moving on the same trajectory after a magnet deflects each onto paths that vary depending on the ion's molecular weight. Herrero used the program's SmartCursor feature to quickly define arcs tangent to the original path of the ions with a radius that reflects their mass. He selected the endpoint of the line representing the original path simply by moving his cursor in that area and selecting the relevant construction the endpoint of the line. VectorWorks automatically locked the cursor onto the endpoint. Herrero then defined the arc, as well as a line tangent to the arc, simply by moving the cursor near the arc and selecting the tangent construction.

"The ability to evaluate the impact of different magnetic sector geometries in minutes, rather than the hours or days that would have been required to perform the relevant computations, made it possible for me to quickly evaluate a wide range of alternatives," Herrero said. "After graphically visualizing the impact of a number of different approaches, I had a hunch that a semicircular pattern might be effective in reducing the size and intensity of the required magnet. I created a slightly convergent set of trajectories representing nonparallel ions entering the magnetic sector and noted that the influence of the semicircular magnetic sector caused ions of a similar mass to quickly converge onto the same trajectory."

Unique design. A conventional magnetic-sector mass spectrometer requires that the ions be deflected over an arc of 180 degrees in order to converge. Herrero's design, on the other hand, converges the ions within plus or minus 2 degrees with a deflection less than 30 degrees . This substantially reduces the amount of magnetic moment required, allowing a considerably smaller magnet.

The first version of this spectrometer was flown in a rocket experiment to study very narrow layers of ionization formed in the Earth's ionosphere between 120 and 200 km altitude. These layers are believed to be less than 1 km thick. Thus the sensitivity afforded by Herrero's design is essential as the rocket flies through the layer with a vertical velocity of about 500 m/s.

Herrero says that the improved visualization provided by the use of CAD to replace mathematical equations saves time and leads to more creative designs. "I have doubts that I ever would have thought of using this new approach if I had been using the traditional hand-calculation approach," Herrero emphasizes. "Having a simple, quick, and graphical way to evaluate ionic trajectories made all the difference in the world."

How a mass spectrometer works

Magnetic sectors bend the trajectories of ions into circular paths that depend on the momentum-to-charge ratios of the ions. Ions with larger momentum-to-charge follow larger radius paths. Thus the mass of the ions can be measured by determining the location at which they strike a detector.

Very small quantities are needed for detection. Atomic and molecular ions can be detected one at a time using electron multiplier technology. Determination of the molecular structure is made when the molecule is ionized. In outer space, ions exist in their natural state and can simply be directed into the aperture of the instrument.

In the early days of mass spectrometry, the photographic plate was the position sensitive detector of choice. Nowadays, with arrays of electron multiplier channels (the so-called micro-channel plates), it is possible to detect one atom at a time at a known position on a plate.

FEA builds stairway to space

Huntsville, AL --Almost daily, satellites are boosted into orbit, providing communications links, military surveillance, and data about the Earth's climate. To boost these big hunks of metal and electronics from lower-Earth orbits to the higher energy, the geosynchronous orbit required can be expensive. So, engineers at the U.S. Air Force Research Laboratory's Propulsion Directorate at Edwards Air Force Base in California are developing a low-cost transportation method.

The concept, called "solar thermal propulsion," involves highly accurately shaped inflatable solar concentrators developed by SRS Technologies (Huntsville, AL). The concentrators drastically reduce cost-to-orbit as they are lightweight, easily stowed on a launch vehicle, and use free, concentrated solar energy to heat the propellant that provides the needed thrust to achieve a higher orbit.

Optical requirements. When deployed in 2002, each solar thermal propulsion vehicle will have two pre-molded, inflatable solar concentrators made almost entirely of a new polyimide material developed by the NASA Langley Research Center (Hampton, VA). The LaRC-CP1^TM polyimide is a clear, lightweight material with a large thermal operating range. It effectively forms compound curved shapes, resists UV radiation, and remains stable in a vacuum.

The solar concentrators must be designed so that their 9 3 13-ft reflectors achieve a precise surface slope when inflated. This ensures that an optimal amount of the sun's energy focuses on the heat exchanger engine that heats hydrogen gas. The expanding gas provides enough thrust to transfer the satellite to the higher orbit.

SRS engineers realized that these solar concentrators might experience excess deflection when inflated in orbit. This would prevent the pre-molded devices from forming the surface shape needed to collect the required energy. To predict the shape and stresses during flight and optimize the concentrator's geometry, SRS used Accupak/VE nonlinear static stress analysis software from Algor Inc. (Pittsburgh, PA), and tested the solar concentrators on a computer.

A solar concentrator consists of two reflectors; each has two symmetrical 0.001-inch-thick layers that are bound together at their edges. One layer contains a reflective coating for focusing solar energy. Hydrogen gas is released between the two layers in orbit to inflate them to the required optical slope.

Jim Moore, program manager at SRS' Aerospace Directorate, modeled one-half of a reflector using Superdraw III, Algor's single-user interface and precision finite-element, model-building tool. He modeled the polyimide layer without the reflective coating for simplification

Moore used 3D plate elements for the reflector and beam elements to represent a catenary suspension system made of Kevlar threads that attach the reflector to an inflatable polyimide support ring. He applied fixed boundary conditions at the catenaries' ends to represent their attachment to the support ring. The support ring maintains the optical shape of the reflector, but was not modeled with Algor because the ring is relatively insensitive to small deflections.

Moore then went to Supergen, Algor's automatic 2D surface-mesh engine, to create an FEA surface mesh and performed manual mesh refinement to enhance the surface mesh before generating a solid FEA mesh. He specified the material properties for LaRC-CP1 polyimide film manufactured in SRS' Polymer Manufacturing Laboratory. He selected an elastic material model to best represent the polyimide's stress-strain curve.

Based on previous analyses with Algor, SRS determined that a pressure of 9.032 3 10^-4 psi applied to each element's surface was necessary to create stress of approximately 200 psi in the reflector's film. This value represented the required hydrogen gas pressure needed to inflate the film enough to remove wrinkles upon inflation, but avoid tearing. The pressure level would also create tension in the supporting catenaries that would best contribute to the ideal surface shape for collecting solar energy.

Moore subjected the solar concentrator model to increased pressure loading slowly over time. He found that applying the load incrementally resulted in a reduced analysis run time and improved convergence.

SRS will create a prototype concentrator based on Algor's analysis results later this year. The introduction of these highly accurate solar concentrators to the aerospace industry will reduce the cost of transferring satellites to a geosynchronous orbit while using a clean, abundant, and safe power source the sun. And along the way, SRS saved thousands of dollars by avoiding the manufacture and testing of prototypes, says Moore.

Jet-fuel hose passes rigid flame test

Ft. Worth, TX-When your customer list includes the likes of Pratt & Whitney, General Electric, and the U.S. Military, you want to make certain the products you supply them pass the most stringent specifications. That's why Stratoflex, a division of Parker Hannifin, turned to a silicone ablative that can survive a direct flame of 2,000F to shield its jet-fuel hoses.

"Thermal stability and flame resistance were the key features in specifying the silicone rubber coating for the hoses, which we test under exaggerated service conditions," says Stratoflex R&D Manager Rick Deiss. "In fact, we expose the material to a 2,000F flame for 15 minutes."

The fuel line, designed around a polytetrafluoroethylene (PTFE) tube, consists of several layers. To contain the fuel pressure and deliver physical protection, the first layer is a stainless steel wire braid, which also serves as a ground for static electricity. "Most of the static electricity is dissipated by a carbon-filled layer within the tubing wall," Deiss adds.

The final layer, the silicone outer jacket, is extruded over the hose assembly. The silicone supplier, Dow Corning STI (Midland, MI), custom pigments the compounds in brown or red, depending on the specific hose design.

"After we produce the hose, we shave a little bit of the material off each end and then insert a fitting," Diess continues. "We crimp the fitting over the hose, and, to maintain the fire resistance, we slide a cuff molded out of silicone over the fitting."

Deiss explains that because the hose is subjected to the ablative test, the silicone material does char, as expected. "After a few minutes under the flame, one layer of ash will drop off, and about five minutes later another layer will fall," he adds. The hoses are typically rated at 400F, and, depending on the type of aircraft engine, they are classified under Mil-H-2557, AS-604, or AS-1339 specifications.

Flame resistance proved the primary concern in selecting a material for this application, but the silicone elastomer's flexability provides an added benefit. Diess notes, "In an engine compartment, the fuel line is located among complex, rigid tubing, and it's helpful that the silicone material can dampen vibrations and absorb mechanical shock."

Contest recognizes global innovation

Newton, MA-Omron Electronics, a long-time supporter of the non-profit Design News Engineering Education Foundation, is creating a new $20,000 "Global Innovation" Award for the year 2000.

"Clearly, the world is becoming a smaller place everyday because of today's advanced communication, logistics, and transportation systems," notes Frank Newburn, President and COO of Omron Electronics Inc. "However, we must be very careful not to mistake the emerging global economy with a homogenous market. As global marketers and product designers, we must be aware of the needs of a multi-cultural global market."

The Global Innovation Award, which provides $5,000 to the winner and $15,000 to the college of his/her choice, will be presented for the first time on March 14, 2000 at the 13^th Annual Design News Engineering Awards Banquet at Chicago's Ritz Carlton Hotel. For the past seven years, Omron has donated $10,000 annually to the Engineering Education Foundation.

The award will honor an engineer who has led the development efforts of an outstanding product that not only features innovative technology but has also been designed for worldwide sale. Says Newburn: "This award was established as a way of recognizing those engineers who have grappled with the unique problems associated with developing innovative products for a global market and have succeeded."

Entries should demonstrate skill in implementing the latest technologies, but also reflect how developers met the additional challenges of cooperating with design partners in other countries and addressing the regulatory, environmental, and cultural considerations that come with designing products for the global marketplace.

Besides recognizing the work of an outstanding engineer, this award will trigger major editorial features in both Design News, with a circulation of 180,000 design engineers in North America, and in Global Design News, serving 40,000 design engineers at the large OEMs in Europe and in the Asia/Pacific Rim region. Representatives of the winning team will also show their product at both the Design News and Omron booths during National Manufacturing Week, March 13-16.

"Two of the characteristics that define Omron are its global nature and the value we put on innovation. The Global Innovation award allows us to recognize engineers from other companies who share these important traits," says Mark Lewis, marketing manager at Omron Electronics.

"There is no limit on the kinds of products and technologies eligible for this contest," adds Publisher Larry Maloney. "What we are looking for are cutting-edge technologies designed to meet the rigorous design challenges of world-wide distribution."

To enter the contest, see details and entry form on page 27. Entry blanks for the contest will appear in all issues of Design News through October, as well as in the September, October, and November issues of Global Design News.

Rockoons still chasing the CATS prize

Sacramento, CA-Two years ago few people would ever think of the words space and balloons in the same sentence, and those who did would usually end that sentence with laughter. Before November 8, 2000, computer programmer John Powell expects to get in on the joke, when JP Aerospace collects a $250,000 prize for launching a rocket into space from a platform suspended 100,000 ft in the air by ten weather balloons. The fantasy like device is known as a "rockoon."

The Cheap Access To Space (CATS) contest, held by the Foundation for the International Non-governmental Development of Space (FINDS) and administered by the Space Frontier Foundation, is offering the $250,000 prize, for the first amateur to deliver a 4.4 lb (2kg) payload to the edge of the final frontier124 miles above the earth. "If we are ever going to open the space frontier to more than a few elite government employees called 'astronauts,' then we need cheap access to space," said foundation President Rick Tumlinson at the contest announcement two years ago.

Progress in access to space has been stagnant because of several things, depending on whom you ask. While several government regulations make it "very, very difficult for small entrepreneurial businesses to launch there (at NASA launch sites) in any type of real time, on a real schedule, on a real budget," says Korey Kline of Environmental Aeroscience Corp., a CATS competitor, and amateur rocket altitude record holder, they don't make it cheap either. NASA's estimated budget for a space shuttle launch is more than $300 million. In contrast, advanced satellites the size of coke cans are available for near $5,000. Technology demands that more efficient, affordable ways to reach space be developed.

Powell's balloon launch method is odd, but not revolutionary. Balloon launched rockets have been in existence since the fifties. The method has not been expanded upon in the last forty years because of obvious shortcomings. Balloons are extremely hard to control at high altitudes because of the weather, which complicates issues around flight corridors and where the rocket will be pointing when launched.

The ten weather balloons used to raise the combined JP Aerospace 42-lb payload of launch platform and rocket are extremely sensitive to winds. At a test launch last May a rockoon succumbed to a shift in the jet stream, causing the balloons to drift out of the FAA approved flight corridor before they could reach the 100,000 ft launch altitude. Rather than scrap the launch completely, engineers decided to launch from 26,000 ft and test systems performance.

Despite the premature launch altitude, "the rocket performed on the numbers, it actually matched, within a half of a percent on the error bars, the performance curve," says Powell. The launch did set a verified amateur world altitude record for solid rockets at 72,223 ft, far from the CATS goal of 654,720 ft.

Advantage paper-thin. The major benefit of launching from 100,000 ft is that the rocket is not pushing through the Earth's dense lower atmosphere. As a consequence, the rocket can be smaller and only has to carry 6 lb of propellant. The "Spirit of Freedom 7," named after the first rocket to take American Alan Shepard to space, weighs only 17 lb, with a phenolic, paper, and epoxy airframe, a carbon-fiber nose cone, and fins made of laminated aircraft plywood and Kevlar. The hybrid liquid and solid fuel propellants being used by the majority of competitors require their airframes to use ceramics, aluminum alloys, and other strong materials, and as a result weigh more.

Even Powell's payload is dedicated to furthering the technology of space transportation. Alfred Differ has developed a 1 3 1-m solar sail, possibly to be applied in orbital transfers and research, that will be deployed once the rocket reaches space. Essentially a propulsion system powered by the pressure of sunlight, sail travel is slow, but much faster than the current two-year method of looping space probes around planets for gravity assist. When rays from the sun strike the surface of the Mylar sail it recoils, similar to a regular sail catching a wind. While it only accelerates at 1mm per second, it covers as much space in one month as gravity assist does in two years. NASA has done research and even built solar sails up to a half-mile wide, but one has never been put into space. Differ, an astrophysicist, could have the first sail in space, in trade for checking the teams' computer simulations by hand.

Keeping in Touch. While the sail and complex launch method may be the main attractions, the star behind the scenes is the team's telemetry system. This package is responsible for tracking the rocket , determining voltages of all batteries, system status, controlling the deployment of the chutes, and transmitting all this data to the ground and accepting uplink signals. Unfortunately, for Powell the price of a conventional system was too high and too heavy at 9 lb. Driven by necessity, JP Aerospace created its own telemetry system with a digital link for less than $2,000 and only weighs 1 1/2 lb, including power supply.

An upgrade planned for the next launch includes accelerometers and magnetometers that will determine the exact altitude of the rocket, which Powell says are, "the key to an orbital insertion burn."

"Everybody is trying something different, but interesting to Powell is the fact that, "one of them may be the thing to do that no one thought of." The "Spirit of Freedom 7" could be used for atmospheric research, by universities as a sounding rocket, or to launch personal satellites. Regardless, the CATS contest promises us all that the sky will no longer be the limit.

Fasten your seatbelts Alternative Technology

Two years ago Korey Kline's Hyperion 1A launched from the ground went to a record altitude of 125,000 ft, a height yet to be achieved by a two-stage rocket. Currently, Kline and the Environmental Aeroscience Co. (eAc), are preparing to capture the CATS prize and outdo themselves, "one of our strategies is to comfortably exceed the requirements," he says confidently.

The hybrid technology uses synthetic rubber as fuel and nitrous oxide (laughing gas) for the oxidizer. Unlike solid fuel rockets, the fuel and oxidizer are kept separate, combining only upon detonation. The 100% pyrotechnic free system doesn't require any explosive permits, training or certified buildings, and results in longer burn times and higher altitudes. eAc is confidant the Hyperion will, and be sought by Universities doing research.

Targeting top employers

Newton, MA -- Before you realize it, the millennium will be upon us and with it a list of resolutions that accompany this celebration...exercise, eat healthy, get a new job.

Every year, Design News compiles the DN100, a listing of the top 100 employers of design engineers to help engineers assess their career choices. The report identifies companies that are pioneering some of engineering's most exciting technologies. And, it profiles some of the big changes during the year, such as acquisitions and buyouts. To see last year's feature story, visit www.manufacturing.net/magazine/dn/ archives/1998/dn1221.98/special.pdf (Adobe Acrobat needed to read file).

If your company is an original equipment manufacturer and you think it would qualify as one of the 100 to appear in this special report, please send your contact information to Anna Allen, Associate Web Editor at [email protected]. She will forward a copy of the survey to you by e-mail.

All entries must be received by August 30^th. The first completed 200 surveys will be entered into a drawing to receive a $100 American Express gift certificate. Don't miss out on the opportunity, submit your entry today.

Pump enables F-18 to use dual pressure

By Charles J. Murray, Senior Regional Editor

Jackson, MSA new, dual-pressure hydraulic pump enables aircraft manufacturers to take a first step toward using higher-pressure hydraulic systems.

The pump, currently in use on the Boeing F/A-18 E/F, allows an aircraft to automatically switch its hydraulic power system back and forth between 3,000 and 5,000 psi.

For the aircraft industry, the move to dual pressure is seen as an important step forward. Operating at 5,000 psi enables aircraft systems engineers to employ smaller, lighter hydraulic actuators. And operating at 3,000 psi prevents the heat build-up and leakage that would ordinarily occur over extended periods at 5,000 psi.

Up until now, the vast majority of aircraft systems operated exclusively at 3,000 psi. "Using this pump, most aircraft would still operate at 3,000 psi about 80 percent of the time," notes Phil Galloway, engineering manager at the Vickers Aerospace Marine Defense Division of the Eaton Corp. "The aircraft would only use 5,000 psi when it really needs it."

The engine-driven pump, designed by Vickers engineers, works in conjunction with the aircraft's flight computer. When the plane reaches a prescribed speed, the flight computer automatically switches the system over from 3,000 to 5,000 psi. Switching at higher airspeeds enables the hydraulics to more effectively deal with heavier loads on the flight surfaces.

The technology could also be important in commercial applications. Some commercial airframe manufacturers are reportedly considering a switch to dual-pressure hydraulics. The higher pressure capabilities would enable the airframe manufacturer to use smaller diameter piping, which could ultimately yield a weight savings of 1.5 metric tons on the aircraft.

Camera-on-a-Chip Technology: You Ain't Seen Nothin' Yet!

By Jean Young Gonzalez, Western Technical Editor

Pasadena, CA-Who can forget the sharp images of Venus, Jupiter, and the Earth taken on recent NASA Shuttle missions with digital electronic cameras? Can you imagine that kind of crispness and clarity in your own camera? Experts with Photobit Corp. (Pasadena, CA) can. In fact, they say new complementary metal oxide active pixel sensor chips (CMOS APS) will revolutionize digital imaging.

Charged coupled devices (CCD) have prevailed in cameras for thirty years, but active pixel sensors have several advantages. CMOS APS draw less power than CCDs, allowing products to run longer on batteries, a big plus for personal data assistants and video cell phones. By combining all camera functions on one chip from capture of photons to the output of digital bits, CMOS image sensors reduce part count, boost reliability and ease miniaturization.

"CCDs employ an analog signal, which means you have to be careful about noise pick up," says Dr. Eric Fossum, chairman and chief scientist at Photobit, who cofounded the company with a former Jet Propulsion Laboratory colleague, Dr. Sabrina Kemeny. "With CMOS digital signal output, the noise problem is conquered," says Fossum.

According to Sabrina Kemeny, another plus of CMOS APS is that an image system can be designed in half the time than with a CCD chip. "You don't have to be a 20-year CCD expert to give a system visual capability anymore," says Kemeny.

APS technology can be used for digital image capture in everything from surveillance and X-ray equipment to laptops and children's electronics.

Photobit's PB-1024 megapixel sensor can operate at 500 frames per second, making it suitable for machine vision and motion analysis. "This unique chip supports dozens of exciting applications," says Kemeny. "It can trace the path of a speeding bullet, analyze a golf swing or help with car crash tests."

In manufacturing, the chip may help in vision applications with volume visualization, sorting, and flaw detection.

High-speed milling could produce monolithic parts

By Charles J. Murray, Senior Regional Editor

Cincinnati, OH-If engineers at Cincinnati Machine have their way, airframe designers may soon be creating new types of floor beams, wing ribs, and fuselage frames.

The giant machine tool manufacturer is nearing the finish of a five-year development program on a five-axis mill that could enable such parts to be quickly created as single-piece, monolithic structures. Currently, airplane manufacturers build floor beams, wing ribs, fuselage frames and other parts as an assembly of hundreds of pieces, including rivets, bolts, plates, channels, and steel angles.

But technology developed on the new machine, known as HYPER-MACH^TM, should eventually enable them to create enormous single-piece parts simply by hogging them out of huge billets of aluminum. The reason: HYPER-MACH offers a combination of size, speed, and power that's never before been available in a machine tool, according to the company. A test stand model has operated at speeds of 2,500 inches per minute with 2g acceleration.

Engineers from Boeing, which initially proposed the machine to Cincinnati Machine, believe HYPER-MACH's technology could yield huge benefits for airframe makers. "When you machine a part out of a plate of material, instead of assembling it, you realize a lot of advantages," says George Neilson, an associate technical fellow in Boeing's manufacturing research and development area. "You don't have to make tooling to hold the pieces together. You don't have to pay someone to pound rivets. And you don't have distortion of the part after you've loaded all those rivets into it."

Linear motor technology. The key to the machine's exceptionally high speed is its use of linear motors. Three of the test stand axes are powered by linear motors, supplied by Anorad Corp. (Hauppauge, NY) and Kollmorgen (Radford, VA). A gimballed spindle operates at speeds up to 60,000 rpm and is rated at 60 kW. The test stand also uses a CNC motion package from Siemens Energy & Automation (Alpharetta,GA).

A prototype of the machine, which is not yet completed, looks unlike a conventional mill. Its movable portion resembles a structural truss. Engineers say that the unconventional appearance, however, was done for good reason. "Historically, machine tool makers have over-designed their machines," says Chip Storie, aerospace industry market manager for Cincinnati Machine. "The solution was always to add mass. But that doesn't work if you want to go fast and turn on a dime."

A key focus of the Cincinnati Machine-Boeing team effort was the development of a virtual prototype that enabled engineers to test the machine's performance before hardware was built. The process was similar to the one used in the famed paperless design of the Boeing 777 aircraft.

The team's engineers used the virtual prototype to deal with speed-related issues, such as vibration and position accuracy. By combining customized dynamic simulation software with a virtual servo system and CNC code, they were able to create a machine that offers greater accuracy than conventional mills, even when operating at speeds in excess of 2,000 inches per minute.

In tests, HYPER-MACH has milled out a thin-walled, honeycomb-shaped part out of an aluminum billet in under 30 minutes. Engineers say that the same process would take approximately three hours on a state-of-the-art high speed machine, or as long as seven or eight hours on a conventional mill.

For airframe manufacturers, the existence of machines like HYPER-MACH is expected to bring dramatic changes. "Because labor is so expensive, the whole industry is moving in the direction of monolithic parts," says Neilson. "But for us to really get to that point, we need to have high acceleration, high-velocity machine tools."

Tiny biosensor chem lab flies on shuttle

Moffett Field, CA-A tiny chemical lab, no bigger than a deck of cards, may evolve from a biology sensors device that flew onboard the Space Shuttle Columbia when it thundered into space this July.

Biona-C's sensors measured pH in cell cultures carried on the Space Shuttle. By combining Biona-C with computer electronics, pumps, and valves, scientists at NASA's Ames Research Center (Moffett Field, CA) are working toward development of a tiny, automated chemical laboratory.

"Project by project, we are making miniaturized parts that will comprise a portable chemistry lab no bigger than a shoebox or a deck of cards and maybe even smaller," says Carsten Mundt, an electrical engineer in the Ames Sensors 2000! program office. "One of our goals is to build smaller and smaller sensors able to make various kinds of physiological, chemical, and biological measurements."

During the flight, fluid ran through Biona-C's tubes and across multiple sensors while nourishing the cells. The tubes containing the sensors are mounted on an electronics board to save space. The Biona-C sensors are part of a 12-inch-long rail that assists cell growth by controlling the fluid flow and temperature of the bioreactor cartridges that contain the cells.

Ames Scientists developed the biosensor system with Walter Reed Army Institute of Research (Silver Spring, MD).

"The unique integration of fluidics and electronics allows us to have a very-sensitive, low-noise unit that is modular," says John Hines, Ames' Sensors 2000! program manager. "Making smaller 'building-block' modular units will enable us to construct tiny, portable chemistry labs."