November 1985
From The Space Library
NASA announced that its Lewis Research Center (LeRC) received four of Research & Development magazine's IR-100 awards to honor the 100 most significant new products developed during the past year. A panel of technical judges selected the winners from more than 1,000 entries. The award-winning products were servomechanism for propeller-pitch change, transmit module, communications traffic processor, and rotary power-transfer device, all of which LeRC and private firms under contracts to the center developed jointly.
LeRC researchers Stuart Loewenthal and Bruce Steinetz with General Electric engineers developed the servomechanism for propeller-pitch change, which could accurately control the propeller blade angle of large (10,000 kw) turboprop aircraft propellers over the complete spectrum of flight operating conditions. With certain modifications, the product should be adaptable for applications as aircraft wing pivot mechanisms, tank turret aiming actuators, and other heavy mechanisms, requiring very accurate pointing and tracking control.
The transmit module, developed by LeRC researchers Thomas Kascak, Godfrey Anzic, and Denis Connolly along with Rockwell Internatl. engineers, provided rf signal amplification and phase shifting at a frequency of 20 gigahertz. The device was of monolithic design in which all module functions were contained on a single 6.4 by 4.8 millimeter semiconductor chip with the smallest circuit feature about 40-millionth of an inch. This development made possible the production of weight- and cost-effective phased array antenna systems for future communications satellite systems.
LeRC engineer Russel Jirberg along with electronics engineers from Motorola Corp. developed a communications traffic processor for the next generation of communications satellites. The system provided the capacity and routing flexibility needed to handle the nation's growing demands for telephone and computer message traffic. When used aboard satellites having multiple narrow beam antennas, the device enabled more than 60,000 individual voice messages, video pictures, and computer data to be routed directly to users throughout the U.S. equipped with low-cost ground terminals.
LeRC engineer David Renz in cooperation with Sperry Flight Systems engineers developed a rotary power-transfer device that transferred electrical power through a rotating joint. It had a low loss space-type design capable of transferring high power (hundreds of kilowatts), AC or DC, to frequencies such as 20 kilohertz. One of its outstanding features was loss of only 22 watts per circuit while transferring 100 kilowatts. Renz and his colleagues said the roll-ring assembly device had the potential to be one of the major components of the proposed space station and other spacecraft where large amounts of power are required. (NASA Activities, Nov 85, 10)
NASA announced that three physicians from Washington University Medical Center, St. Louis, Missouri, met the previous month with NASA scientists from National Space Technology Laboratories (NSTL) to discuss using remote sensing techniques as an analytical tool for use in the field of body scanning known as nuclear magnetic resonance or NMR. Dr. Michael Vannier, radiologist and principal investigator for the project, said NMR was already used on a number of organ systems in the brain. However, interest had grown in how magnetic resonance imaging might fit into the scope of breast diagnostic techniques. So Drs. John Gohagan and Ed Spitznagel, also of Washington University, on behalf of the National Cancer Institute's Breast Imaging Project joined Vannier at the discussions.
The meeting resulted in a three-year collaborative effort among the Mallinckrodt Institute of Radiology in St. Louis, NSTL, and the Kennedy Space Center.
Vannier commented that the union with NASA was vital to maximize the potential of NMR scanning. "One of the characteristics of these magnetic resonance scanners is that they provide very specific anatomic information about the location and size of a tumor. However there are other ways to get the same information, one being the use of a mammogram, or breast X-ray." At NSTL, scientists Doug Rickman and Jim Anderson were responsible for applying the analytical capabilities to make NMR scans a notable advancement over other methods of X-ray and body scanning techniques. They had demonstrated the use of ELAS software to enhance NMR images, thus increasing disease detection accuracy. Vannier explained, "No one in medicine really has the kind of experience with classifying or analyzing these types of images this way. That's why we are using NASA expertise to help us." By incorporating the ELAS software used in processing satellite imagery into the system, NMR scans could provide not only information on the location and size of a tumor, but also its biological behavior. That is, physicians could determine the status of a mass of tumor directly from the NMR image without having to enter the body surgically.
Close affiliation with pathologists while working on actual cases was important in determining whether there had been misclassification on the image processing machines, Gohagan said. "Our goal is to ultimately get the kind of discrimination necessary to distinguish different anomolous conditions," he explained. For example, blood clots would appear distinctly different from benign tumors, and a marked difference would be evident between benign and malignant tumors.
Vannier concluded that, as a result of the collaboration, an improvement should evolve in the way NMR images are acquired. "I think it will have significant influence on what we do in the future," he said. (NASA Activities, Nov 85, 7)
Gene Gilbert, a technician in Goddard Space Flight Center's (GSFC) Laboratory for Oceans was searching for a way to measure rainfall at sea by using an oil rig, Goddard News reported, in order to assist in the development of a system called the Tropical Rainfall Measuring Mission (TRMM). TRMM could take the form of a satellite or space station attachment operational in the mid-1990s to improve upon rainfall sensors that flew aboard Nimbus satellites. But developing better sensing capabilities first required accurate ground truth measurements to test the accuracy of remote observations.
Over the years, meteorologists had developed a good picture of weather over land masses. But they still needed to know what happened over the remaining two-thirds of earth. When putting a collection bucket on a ship, Gilbert explained, different locations on deck gave differing results depending on whether the bucket was sheltered from the wind. In addition, the ship's movement gave angular measurement of the rain, not a true vertical one. And a buoy was not an improvement. "It may look stationary," Gilbert said, "but it really is not." Even the largest ones, which were 50 feet across, tossed in a storm, splashing and spraying and negating results.
"What is needed," Gilbert pointed out, "is a surface that is stationary, vibration free, and splash-proof. I think oil platforms could satisfy all those conditions." GSFC's Microwave Sensors and Data Acquisition Systems Branch in July placed the first rain gauge on a oil producing platform in the Gulf of Mexico off Lafayette, Louisiana. "The very next month a hurricane knocked out our data transmission antenna," Gilbert recalled. "But we repaired the damage easily, and we have been getting good data since then." The rain gauge was a teeter-totter with a shot-glass sized cup at each end. The cups filled successively with 1/100th of an inch of rain and then dropped the measure back into the ocean. Each count was transmitted to the National Oceanic and Atmospheric Administration's (NOAA) Geostationary Operational Environmental Satellite (GOES) and then back to GSFC via NOAA's data processing facility in Suitland, Maryland.
"The goal is to demonstrate that using a gauge on an oil rig gives us our most accurate ocean rainfall data to date," Gilbert said. "If it does, we may expand to include other oil rigs. Then we will finally have good ground truth data for measuring rainfall over the ocean by satellite, at least for those oceans that include oil rigs." (Goddard News, Nov 85/ 2) November 29: NASA's Jet Propulsion Laboratory (JPL) pioneered the concept of a satellite system for mobile users and, because a U.S. mobile satellite industry was emerging, was turning its attention to developing technologies critical for future systems, the JPL Universe reported.
Similar to cellular phones popular in urban areas, the mobile satellite system (MSS) would provide voice and data communications for the entire North American continent, employing one or two satellites in geosynchronous orbit to relay communications instead of depending on ground-based, line-of-sight relay towers that cellular phones used.
There were four categories of MSS users: people who needed uninterrupted communications while they traveled over wide geographical areas, for example interstate truckers; those responding to unpredictable events such as medical emergencies or natural disasters; people working at planned but temporary installations such as oil or gas drilling facilities, mining camps, or archeological excavations; and those in very remote areas.
The new technologies JPL was developing included mechanically steerable low-profile and electronically steerable medium-gain vehicle antennas, digital speech compression, digital modems, and multiple-access techniques for integrated voice and data.
NASA was working with industry and, through a joint endeavor agreement, would exchange a Space Shuttle deployment for 15% of the channel capacity for two years to test the system. "But first," said Dr. Firouz Naderi, JPL's mobile satellite experiment project manager, "we must further develop the technology and try to squeeze as many channels as we can from a very narrow frequency allocation. That is the biggest obstacle we face." Also, JPL must design sophisticated multi-beam antennas that service "spot areas" and create techniques so frequencies could be reused to provide the most efficient use of the limited spectrum.
Recently JPL sponsored a two-day briefing on the state of the industry. Attending were more than 250 representatives of 120 organizations including the Federal Communications Commission (FCC), which would regulate the MSS; 11 of 12 candidate companies that petitioned the FCC for the right to operate the system; communications equipment manufacturers such as General Electric, Harris, and Motorola; Canadian government and industry representatives; banking officials; and potential users of the system. At the briefing, the FCC said it hoped by the middle of 1986 to assign a frequency to the mobile satellite industry as well as license an operator to be in charge of the system.
NASA scheduled for launch in 1990 the first generation satellite with a 5 to 7 m antenna. During the program's second phase, NASA would launch from the Space Shuttle a 20m (65 ft.) antenna. NASA then planned for the program's final phase to construct on the proposed space station a 50m (180 ft.) antenna for deployment into geosynchronous orbit. (JPL Universe, Nov 29/ 85, 1)
Quoting from the Congressional Record, NASA reported remarks of Rep. Don Fuqua, (D-Fla.) chairman of the House Science and Technology Committee, who introduced the Federal Science and Technology Revitalization Act of 1985.
The act ". . . would establish an alternative personnel management system for scientific and technical people in the federal government," Fuqua said. "This is something I have been interested in for a long time, and I am hopeful that the proposal I am introducing will be able to help improve the quality of government-operated federal laboratories by encouraging the recruiting and retention of highly qualified scientific and technical individuals." Major provisions of the bill would permit agencies to include scientific and technical personnel in the new personnel management systems; simplify job evaluation and remove covered positions from the classification requirements of 5 U.S.C., Chapter 51; provide flexibility to develop a salary structure that ensured a competitive position in the labor market and that reflected the hiring and pay policies needed to attract, retain, and motivate a highly qualified scientific and technical work force; increase base pay on performance, not longevity; allow waiver of the pay cap for up to 5% of specially qualified scientific and technical personnel; provide for performance and special awards and remove the pay cap for lump-sum awards; and create a senior scientific and technical personnel service.
In May 1983 the Federal Laboratory Review Panel of the White House Science Council chaired by David Packard reported that federal laboratories had several serious deficiencies and, consequently, a number of them did not meet the quality and productivity standards that might be expected, Fuqua explained. The panel reported that salaries at federal laboratories were noncompetitive with the private sector at entry and senior levels and that federal laboratories had to deal with a personnel management system that was cumbersome and had little flexibility.
As a result, there existed what the panel referred to as an alarming "inability of many federal laboratories-especially those under civil service constraints-to attract, retain, and motivate qualified scientists and engineers." The panel concluded that administrative and legislative actions should be initiated to create, at government-operated laboratories, a scientific-technical personnel system that was independent of current civil service personnel systems, Fuqua continued.
This "bill is the legislative attempt to deal with these very real problems," Fuqua said. "My own experience . . . is that the requirements for NASA and Department of Agriculture labs may be very different, but attracting and retaining quality personnel is absolutely essential for the space program and for emerging fields in agriculture." (NASA Activities, Nov 85, 9)@@@ November 29: New observations supported the prediction that Saturn's satellite Hyperion was tumbling wildly rather than rotating with a regular predictable period, Science reported.
In 1983 Jack Wisdom, who was currently at the Massachusetts Institute of Technology, and his colleagues predicted that the combination of Hyperion's odd potato shape and the stretching of its orbit by the gravitational tugs of the larger satellite Titan would prevent Hyperion from rotating regularly. Instead of keeping one face toward Saturn, as the moon faced earth, Hyperion would rotate chaotically, tumbling one way then another, slowing down and speeding up, in a fashion impossible to predict in any detail from its preceding behavior.
Since then, Peter Thomas of Cornell University and his colleagues reported analyses of the brightness of Hyperion in Voyager images that indicated a regular 13-day period of rotation during the 61 days of Voyager-2's encounter with Saturn.
Jack Wisdom and Stanton Peale of the University of California, Santa Barbara, countered that determining a period from 14 brightness observations scattered over several supposed rotations could not determine whether the rotation was chaotic or not. They found many periods by similarly sampling a numerically generated chaotic light curve.
The University of Texas's Richard Binzel, Jacklyn Green, and Chet Opal reported at a recent meeting of astronomers that the light curve of Hyperion they observed in April was "highly inconsistent with a 13.1-day rotation period." On April 16 and 17, Hyperion's magnitude was at a maximum for the 14-day observing period; it faded by 1 magnitude by April 21 and was no brighter 13 days after the first observations. It should have become 1 magnitude or 2.5 times brighter if it had a 13-day period. Although the observations did not prove chaotic rotation, the group said, "they provide strong evidence in favor of the hypothesis." To say much more about Hyperion's rotation, astronomers would have to observe Hyperion nightly for many weeks, something that those assigning telescope time had been reluctant to permit. (Science, Nov 29/85, 1027)
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