Across composite and metallic aircraft structures, technology is being developed and deployed to minimize component lead times, reduce manufacturing costs and increase production rates. Automated processes that can take component geometry data directly from three-dimensional design databases are high on the most-desired list for aerospace manufacturers.
Cutting and drilling of cured composite components during manufacture or repair are a growing challenge as structures become bigger, more complex and costly.
Friction welding fuses metals without melting them and is used in aerospace to join engine disks (rotational welding) or fabricate aircraft and spacecraft structures (friction-stir welding). Now hybrid components produced by linear friction welding of dissimilar metals promise to overcome a key disadvantage of composites: carbon fiber cannot be attached directly to aluminum because of galvanic corrosion, forcing use of higher-cost titanium. But friction welding can allow titanium to be incorporated into the join between aluminum and composite structures.
Isogrids are among the lightest and strongest of structures, the lattice pattern of integral stiffening ribs providing extremely high strength-to-weight ratios. Lightweight isogrid panels machined from aluminum plate to produce thin-walled, self-stiffened and damage-tolerant structures are used in launch vehicles and aircraft doors. Advanced grid structures made from composites have been used for components such as payload shrouds, but require time-consuming and costly manual layup. Isogrid Composites Canada Inc.
Composites may be replacing metals in aircraft structures, but the use of titanium is increasing both to reduce weight and because of the incompatibility of aluminum and carbon fiber. Boeing's 787 is 50% composite by structural weight, whereas its earlier 777 is only 12%, but a 787 contains almost 90 tons of titanium compared with 55 tons in a larger 777. And titanium can be around 10 times as expensive as aluminum, so pressure is on to reduce costs.
Nanotechnology-enabled materials are moving into aerospace. New Hampshire-based Nanocomp Technologies is scaling up production of electrically and thermally conductive yarn, sheet and tape made from long carbon nanotubes (CNT). Spun yarn is being used to replace copper in data cables in aircraft and spacecraft, potentially halving the weight of wiring harnesses. Sheet material was used on NASA's Juno spacecraft, launched in August 2011, to provide electrostatic-discharge protection of attitude-control thruster and main-engine components.
Engineers on Boeing’s CST-100 commercial crew vehicle project are turning their attention to a forward heat shield jettison test and a hot fire of the capsule’s orbital maneuvering/attitude control engines.
AEHF SCRUB: The U.S. Air Force scrubbed an attempt to launch the second Advanced Extremely High Frequency (AEHF-2) secure communications satellite on May 3 due to a lack of helium flow from ground support equipment into the Interstage Adapter compartment on the Atlas V rocket. Launch provider United Launch Alliance and the Air Force plan another attempt to lift off from Space Launch Complex-41 at Cape Canaveral AFS, Fla., on May 4 during a two-hour window that opens at 2:42 p.m. EDT.
NASA will contract with Boeing for an interim cryogenic propulsion stage to power at least the first two flights of its planned heavy-lift Space Launch System.
A bid by SpaceX to carry out the first U.S. commercial resupply mission to the International Space Station (ISS) is unlikely to lift off May 7, the latest target launch date, according to the company. “SpaceX is continuing to work through the software assurance process with NASA,” according to a May 2 update from company spokeswoman Kirsten Brost Grantham. Earlier, the company slipped a planned April 30 liftoff to allow more time to work software flight-control issues for the planned 18-day test mission.
HOUSTON — Spaceflight brings a whole new meaning to dressing for success. An astronaut’s garments must be functional, yet as comfortable as possible, whether the flier is sealed inside a spacecraft or on a spacewalk. As NASA envisions a future of deep-space exploration and missions stretching from months to years, the list of wardrobe requirements soars as well.
BEIJING — China plans to add three more satellites to its Compass positioning system this year, following the successful launch of two sats by a single Long March 3B rocket on April 30.
LOS ANGELES — The Operationally Responsive Space (ORS) office is pushing ahead with preparations for three more missions and continuing a key military utility assessment of the ongoing TacSat-4 tactical test spacecraft, despite uncertainty over its future after being zero-funded in the White House’s fiscal 2013 budget.
GOES-R: Lockheed Martin has completed the spacecraft critical design review for the Geostationary Operational Environmental Satellite-R series (GOES-R) satellite system that the company is building for the National Oceanic and Atmospheric Administration and NASA. “The team demonstrated that the design and operations are understood and sufficiently mature to begin the build and integration phase,” Lockheed said in a May 1 announcement. The first spacecraft in the next-generation weather satellite series is due for launch in 2015.
LOS ANGELES — Lockheed Martin is ramping up final assembly work on the flight test version of the Orion crew module as workers at NASA’s Kennedy Space Center (KSC) begin verification checks on the Orion ground test vehicle.
NEW DELHI — India plans to launch dedicated communication satellites for the Navy and Air Force between 2012 and 2014, Defense Minister A.K. Antony says. The naval satellite is planned to be launched in 2012-13, while the air force communication satellite is planned to be launched in 2013-14, Antony said in a written reply to a question in parliament on April 30.He also says that the tri-services defense communication network (DCN) is progressing as per India’s defense procurement procedures.
PARIS — French aerospace engine supplier Safran has finalized the merger of two subsidiaries, energy materials specialist SME and solid-propulsion-motor manufacturer Snecma Propulsion Solid (SPS), Paris-based Safran announced April 30.
SAN FRANCISCO — Far-infrared astronomy is not done from ground observatories and has only been possible from a few orbiting telescopes, so the addition of the High-resolution Airborne Wideband Camera (HAWC) to NASA’s Stratospheric Observatory for Infrared Astronomy (Sofia) will allow astronomers to fill a void. On April 19, NASA said it had selected two additional instruments to expand HAWC’s research range.
HOUSTON — A three-man, U.S. and Russian crew departed the International Space Station (ISS) early April 27, descending to Earth aboard their 28 Soyuz spacecraft for a safe ending to a 165-day mission that was marked by major hard- and software upgrades to the orbiting laboratory’s command and control functions as well as a rigorous research agenda.
