UK STUDIES NEUTRON STRIKES ON AVIONICS
RELIABILITY As memory chips get smaller, avionics are becoming more susceptible to neutron strikes and new £140 million ($290 million) facility to test the effects of neutron radiation on aircraft and spacecraft electronics is nearing completion in the UK. Neutrons can strike a silicon chip every few seconds, causing an electrical charge "shower" that can interfere with normal operation. Each strike is known as a single event effect (SEE), and the strike rate is greater at higher altitudes. "SEEs are now recognised as the dominant reliability issue for avionics in the coming decade. Naturally occurring neutrons in the atmosphere are the most intractable source of SEE in electronic components, because they are too penetrating to be shielded [against]," says Andrew Chugg, senior technical expert with MBDA. The missile manufacturer leads a consortium of aerospace companies in the UK government-supported SPAESRANE project studying the effects of cosmic radiation on electronics.
GAS LUBRICATES HIGH-SPEED BEARINGS
OIL FREE NASA's Glenn Research Center is investigating oil-free turbomachinery using foil bearings that can withstand high speeds and temperatures using gaseous lubricants. The bearing uses corrugated "bump foils" under a smooth top foil to provide the compliant surface, and NASA's baseline thrust-bearing design uses several layers of bump foils to tailor the stiffness under load. Using six Inconel X-750 thrust pads, each covering 45°, the foil gas bearing can withstand speeds above 3 million DN (shaft diameter in millimetres multiplied by speed in RPM) and temperatures above 400e_SDgrC (752°F).
ATLANTIC TEST FOR OPTICAL COMMUNICATIONS
LASER LINK Germany's Oerlikon Space is to establish an experimental optical communication link between the Spanish Atlantic islands of La Palma and Tenerife using a pulsed laser. Developed under the European Space Agency's Dolce project, the pulsed laser is designed to provide 10Mb/s data communications between the Earth and the L1 or L2 Lagrange points, the locations for future ESA scientific missions - a distance of 1,500,000km (930,000 miles). The test transmission distance between the two islands is 142km. "A novel feature of the Dolce communications link is that a pulsed modulation format [can overcome] atmospheric turbulence effects, allowing a ground-based optical telescope to be used as the receiver," says the company.
ELECTRON BEAMS POINT TO NEW APPLICATIONS
MANUFACTURING UK firm Aquasium Technology is seeking strategic partners to develop its next-generation electron beam technologies, including the ability to texture surfaces to improve the bonding of dissimilar materials. Surfi-Sculpt uses an electron beam to create geometric arrays of millimetre- to micron-sized features that increase the surface area of metal and non-metallic substrates. Pre-production prototypes are being produced for customer evaluation. Reduced-pressure electron beam welding eliminates the need for a "hard" vacuum, reducing cost and removing limitations on the type and size of components that can be welded. Electron beam free-form fabrication can be used to produce near net-shape parts or repair damaged components from expensive alloys and materials by consolidating wire feedstock.
ANDREWS GETS FAST START FROM AFRL
SPACEPLANE Seattle-based Andrews Space is to design and build a cryogenically insulated integrated tank and structure for the US Air Force Research Laboratory's Future Responsive Access to Space Technology (FAST) programme. The pathfinder structures experiment will reduce risk for FAST ground experiments to be conducted over the next four years and focused on a "vision X-vehicle" design for a rocket-powered vertical-launch/horizontal-landing flight demonstrator. FAST is supporting US Department of Defense plans to field a capability to launch satellites at short notice.
Source: Flight International