January 1985

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“The Planets: Between Fire and Ice” article appears in National Geographic Magazine

NASA announced that its new findings on the nature of high-altitude, clear-air turbulence (CAT), based on data gathered from airline flight-data recorders, could eventually lead to CAT prediction, enabling pilots to fly around the invisible wind swirls.

The findings provided the first detailed description of hazardous, clear-air turbulence, a series of swirls or vortices of air embedded in upper-level wind streams at altitudes between 35,000 and 40,000 feet. The findings also showed that a jet traveling at 500 mph flew through a single-vortex core in about one second. During that second, the wind would push the plane upward and then down, exerting the weight of an extra G (a measurement of gravity) on passengers. Planes might encounter two to four vortices in succession about four seconds apart, possibly causing injury to flight attendants and passengers without fastened seat belts.

Ames Research Center investigators had found that the strongest vortices occurred at about 25 miles downwind of large thunderstorms or mountain ranges, which caused a swell in the upper-level wind stream, and that wind shears formed vortices at the tropopause, the boundary between the troposphere and the stratosphere. At the tropopause, higher-velocity jet streams traveled just above lower-speed windstreams, the difference in the speeds forming a wind shear. The investigators had verified that wind-shear layers, pushed up over a thunderstorm or a mountain range, acted like ocean waves when forced to rise over an obstacle. The air would form a series of swells that turned to waves that curled like those on the sea. They would continue to curl until they formed complete circles or vortices that whirled at high speeds before disintegrating.

As a result of its research, NASA hoped one day to be able to give pilots better indications of when and where they might encounter the vortices. (NASA announcement, Jan 85, 9)

NASA announced it had conferred its Space Act Awards on four Johns Hopkins Applied Physics Laboratory personnel for the invention of a medical device based on space and aeronautics technology. The invention, a programmable implantable medication system (PIMS), was a computerized pump intended for implanting in the human body to dispense medicine automatically to treat disease such as diabetes, cancer, and cardiovascular problems.

A nonhypodermic device introduced medication to a reservoir located in the PIMS device so that its tiny battery-powered pump could send the medicine into the body via a tube in minute doses precisely timed by one of two clocks within the PIMS. A small computer in the PIMS analyzed its performance and operated an alarm if the device was malfunctioning or about to run out of fluid.

NASA technologies employed in the PIMS development were space microcircuitry, titanium welding, and the pump and fluid-handling systems used on the Viking spacecraft and space-program techniques of quality control.

Award recipients were Robert Fischell, Wade Radford, Albert Sadilek, and Arthur Hogrefe. (NASA anno Jan 85, 14)

A six-man Goddard Space Flight Center (GSFC) team at the South Pole on December 14, 1984, had taken turns talking to colleagues in Greenbelt, Maryland, using one of two unprecedented satellite communications links the group had installed over the previous month, the Goddard News reported. "The conversation was amazingly audible," said Tony Comberiate, a GSFC communications expert and member of the South Pole satellite data-link project team. "The folks at Goddard sounded like they were just a few feet away." Although voice communications capabilities from the South Pole using Ham radio had existed for some time, the systems were weather dependent and usually very noisy. The GSFC group used the 17-year-old Applications Technology Satellite (ATS-3) to establish the two-way voice link. The key breakthrough was installation of the scientific data link, which enabled daily transmittal of information from the Pole, across Antarctica, and to the U.S.

Before system installation, scientific data from the pole was stored during the region's winter months and shipped out by aircraft from November through February. The new system permitted transmission of high-quality scientific data by using three existing polar orbiting satellites (a 4th was scheduled soon). Each satellite passed the pole about 14 times daily and relayed data to McMurdo Sound, which retransmitted it to a geosynchronous satellite, which in turn transmitted it to the U.S. Since the Pole signals were too far below the horizon to be acquired by normal communications satellites, the relay route was necessary. Researchers had previously considered a communications link from the South Pole, but decided it was too costly and impractical, perhaps taking several years and costing an estimated $35 million. The GSFC approach had cost about $250,000 and taken nine months, because it used existing satellites, excess equipment, and had support from several organizations.

Scientists could receive daily transmission of reliable data on global weather patterns, the magnetospheric cusp, upper atmosphere, and glaciological and seismic studies to name a few. The link also could evolve into a data collection network for many of the unmanned observatories (ground-based satellites) scattered throughout Antarctica. (Goddard News, Jan 85, 6)

U.S. Space Policy

The U.S. government released an unclassified version of the National Space Strategy based on the National Space Policy President Reagan unveiled on July 4, 1982, and on his 1984 State of the Union Address, Space World reported. The strategy identified selected high-priority efforts and responsibilities and provided for implementation plans for major space-policy objectives.

The document gave new impetus for future manned military-space operations, underscored Administration support for the space station program and establishment of future civilian-space goals, encouraged space commercialization, ordered a joint NASA/Department of Defense (DOD) study of post-1995 launch vehicles, and called for full Space Shuttle cost recovery by October 1, 1988.

Gilbert Rye, director of space programs for the National Security Council (NSC), said of the strategy: "To our knowledge this is the first document of its kind to lay out in any coherent manner a list of priorities that cover the total U.S. space program. It should be useful for the Congress, the private sector, executive branch agencies, and the American people to fully understand the main thrust of the U.S. space program in the years to come." The strategy authorized DOD to procure a limited number of expendable launch vehicles to complement the Space Shuttle, but did not specify particular civilian space program goals. A Presidential National Commission on Space during 1985 was to identify goals, opportunities, and policy options for the U.S. civil space sector for the next 20 years. (Space World, Jan 85, 8)

Aeronautics

NASA announced it was testing a concept, called laminar (air)-flow control, which removed the layer of air molecules nearest an aircraft's wing surface to increase transport-aircraft flight efficiency. Since air/ skin friction during a subsonic flight's cruise phase caused about one-half of the total drag on an aircraft, the laminar-flow control would use suction through porous wing surfaces to remove the turbulent air, reducing drag and fuel consumption.

NASA contractors had designed and fitted two laminar flow-control systems on the leading edge of each wing of a JetStar four-engine light transport. Gloves, perforated either by more than a million tiny suction holes or by narrow slots, encased the systems. Lockheed-Georgia Corp. had designed the test article on the JetStar's left wing; Douglas Aircraft Co. the one on the right wing.

Lockheed's construction was a sandwich of nomex-honeycomb core and graphite epoxy-face sheets, covered by a thin sheet of titanium bonded to the surface. Slots in the titanium sheets, .004 in., ran the length of the section and were the openings that drew air through the surface, directing it down ducts in the wing into the fuselage. The Douglas test article, instead of slotted, was perforated by an electron beam that drilled 800 precise, nearly microscopic holes per sq. inch of wing surface.

Both concepts had built-in systems to keep the wing surface insect and ice free. The Lockheed system pumped a cleansing fluid through the slots to the surface, making it too slippery for insects to adhere. The Douglas concept used a retractable insect shield deployed in front of the leading-edge panel during takeoff, climb, descent, and landing.

After tuning the leading-edge systems for best performance, NASA would flight test the airplane at various locations around the country at different times of year to record effects of weather and insect conditions.

Langley Research Center (LaRC) researchers managing the project pointed out that one energy-saving transport configuration, already efficient by today's standards, would be 22% more efficient with the addition of laminar-flow control. (NASA announcement, Jan 85, 7)

NASA announced that up to 20% of all fatal light-airplane accidents might be preventable with a LaRC- and ARC-developed wing modification, a carefully designed "glove" placed over the outer portion of a wing's leading edge and covering about the first 6 in. of the upper surface and first 18 in. of the lower surface. The glove was lightweight, had no moving parts, and required no maintenance. Wind-tunnel and flight tests of reshaped wings had revealed greatly increased resistance to airplane spins, which could result in aircraft stalls.

Before modification, three test airplanes would enter a spin about 18 of every 20 times pilots stalled wings and applied pro-spin controls. With LaRC's wing leading-edge design, the same planes had entered a spin only once in every 20 attempts. The spins that did occur had required improper airplane loading or extremely aggravated pilot inputs. And the pilot usually had three to four times as long (measured in seconds) to make a correction before the plane entered a spin.

NASA hoped ultimately to provide airplane designers with the ability to incorporate the modification as an integral part of a wing, rather than as an add-on, and the analytical tools to determine amounts of spin resistance for new planes. NASA was expanding the research beyond the series on unswept, low-wing airplanes to include high-wing planes and those with different airfoil shapes. (NASA anno Jan 85, 12)


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