Dec 13 1985
From The Space Library
Kennedy Space Center (KSC) director Dick Smith and Lockheed Space Operations Co. president Doug Sargent today hosted a dedication ceremony for KSC's launch pad B after six years of modification at a cost of $150 million, the Spaceport News reported. NASA would use pad B, the second of the two complex 39 launch pads to undergo modification from the Apollo configuration, to support Space Shuttle and Shuttle Centaur upper stage launches. First launch from the modified pad would be Space Shuttle mission 51-L, scheduled for January 22, 1986.
NASA first used pad B in May 1969 for the Apollo 10, third manned Saturn V/Apollo launch. Its last use was for the launch of the Apollo/Soyuz mission in July 1975.
Pad modifications included a new Centaur rolling beam, permanent orbiter weather protection system, TV camera floodlights and a TV camera system, boxcars, upgrading of the payload changeout room, a cost-saving lighting system, variable speed motors for loading liquid oxygen, and hydrogen flare stacks.
Although there were currently minor differences between pads A and B, the work underway at pad A would eventually make the two functionally identical. (Spaceport News, Dec 20/85, 1; Kennedy Space Center Release 242-85)
Langley Research Center announced that the Space Shuttle Columbia would carry three experiments on mission 61-C developed at the center to measure the spacecraft's aerodynamic and thermodynamic characteristics.
Columbia, the first Space Shuttle orbiter to go into space, was making its first flight in two years after it was pulled from flight service in December 1983 for extensive overhaul, including modification to accommodate the LaRC experiments, which were the Shuttle Entry Air Data System (SEADS), Shuttle Infrared Leeside Temperature Sensing (SILTS) experiment, and Shuttle Upper Atmosphere Mass Spectrometer (SUMS).
SEADS would measure the distribution of air pressure around the orbiter's nosecap during entry to provide precise determination of the orbiter's attitude relative to the oncoming airstream and the density of the atmosphere through which it had flown. Lack of this air data had hindered engineers from determining aerodynamic flight characteristics of the orbiters.
The SUMS experiment complemented the SEADS experiment by gathering atmospheric density information at altitudes above 90 km (56 statute miles). SUMS would sample the gas at Columbia's surface through a small hole located just aft of the nosecap and forward of the nosewheel, with its instrument identifying and measuring the quantities of the various gas species present. Data analysis after the mission would allow determination of atmospheric density.
The SILTS experiment would obtain high-spatial-resolution infrared images of the upper (leeside) surfaces of the orbiter's port wing and fuselage during entry through the atmosphere. These infrared images would provide detailed “maps” of the surface temperatures of leeside thermal protection materials, indicating the amount of aerodynamic heating on the leeside surfaces in flight. (LaRC Release 85-99)
NASA announced that during 1985 it began a series of research flights under simulated airline conditions to evaluate the effects of an operational environment on new technology for smooth, or laminar, airflow over aircraft wings [see Aerospace R & D/Aeronautics, July 8]. Previous research had shown this technology could reduce aerodynamic drag from 25 to 40% under laboratory conditions and could provide significant fuel savings. However, insects, ice, and other obstructions could disturb laminar flow in actual flight service.
To test the system in an operational environment, NASA's Ames/Dryden Flight Research Facility's business-sized Jet Star, equipped with two experimental laminar flow control devices, was based in Atlanta and flown in and out of commercial airports in the southeast and midwest, including those in St. Louis, Cleveland, and New Orleans, to test the devices in humid summer climates.
While based in Pittsburgh to test the devices in early autumn east coast conditions, the plane flew in and out of airports in Boston; Chicago; Chattanooga; Cleveland; Charleston, W.Va.; Washington, D.C.; Detroit; Bangor, Maine; New York; Kalamazoo, Michigan; Oklahoma City; Albuquerque; and Denver among others.
The flight tests would continue in 1986 with the plane based in Cleveland during January. (NASA Release 85-170)
NASA announced that researchers at its Langley Research Center (LaRC) were developing use of pyrotechnic-activated emergency exit systems that might save lives in an emergency situation aboard commercial transport aircraft.
Although pyrotechnic components aboard commercial aircraft might seem dangerous, Laurence Bement, an aerospace technologist specializing in pyrotechnic-activated aircraft escape systems, pointed out that military aircraft had used such escape systems for more than 20 years and NASA had used them in their manned spaceflight programs as far back as Project Mercury in the 1960s. The emergency egress system he proposed would be more reliable and more effective in aiding the rapid evacuation of airplanes and more cost-effective than existing mechanical and electrical systems. “What we have done is take the best materials and applications from years of pyrotechnic usage and tried to assemble the best escape system, using our past experiences;' Bement said.
One U.S. Air Force system, the emergency life-saving instant exit, used pyrotechnic chargers to sever a panel inside the aircraft door. Another, the NASA general aviation egress opening system, created by an explosion an opening in the fuselage without modifying the airframe structure. The pyrotechnic-activated escape systems on U.S. armed forces planes had already saved approximately $10 million by avoiding component replacement costs. However, they added weight and complexity to the aircraft and do not increase the structural efficiency of the airframe.
To improve existing systems, Bement studied the possibility of replacing fuselage skin sections with an explosively severed, composite material panel. Researchers had tested graphite/epoxy and fiberglass composite panels, demonstrating that the graphite/epoxy was the better material. Not only was the graphite/epoxy easier to sever than the original fuselage material, but the composite panel was much lighter and more crashworthy. Once activated, the explosive material severed the panel from the fuselage and jettisoned the panel outward. No debris was projected inward and no sound or over-pressure hazard existed inside the aircraft.
The composite system was more reliable than existing mechanical and electrical systems and would require less maintenance, since the system was expected to last at least 15 years. Bolts would hold the composite panel to the primary structure and it would be a load-carrying component, unlike existing emergency exits.
Bement estimated that using composite panels with the pyrotechnic system could reduce the weight of existing emergency exits by 30 to 50%. If the airframes were designed to include the composite panels, the weight reductions would be far greater, because the light-weight composite panels were capable of carrying loads, meaning the fuselage would not require as much support structure around the emergency door frames.
The explosive in the system was hexanitrostilbene (HVS), an organic compound insensitive to handling, impact, gunfire, and lightning and was unaffected by 50 hours of exposure to temperatures of 350° F. HNS would burn if exposed to a flame but would not explode.
Another advantage of the compound was its explosive power; in a test of the Langley general aviation opening system, less than 0.4 ounce of the compound was sufficient to sever a panel about 30 square inches. (NASA Release 85-171)
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