Nov 7 1985
From The Space Library
Kennedy Space Center (KSC) awarded ASEA Robotics Inc. a $1,143,622 contract to build a robotic development prototype system to be installed in the Robotic Applications Development Laboratory (RADL) and serve as KSC's control center for robotics, Spaceport News reported. KSC currently had two labs for robotics research: Lab A was a test facility for training devices, sensor and end-effector development, and small robotic projects; Lab B functioned as a control center made up of complex work cells and "smart systems" (independent control systems integrated into one coordinated system) for large robotic applications.
The objective of the new system was to permit engineers to combine existing and new technology to create advanced independent and semi-independent machines and machines with independent decision-making capabilities or a "computer brain," which could accomplish more on their own without step-by-step instructions from human supervisors. The initial thrust of the new system would be to develop the technology and techniques needed to automatically load and unload hazardous fuels aboard space vehicles and payloads during prelaunch ground operations. Future challenges included application of these refueling techniques to other fuels such as cryogenic propellants.
RADL would have an electrically driven articulated robot composed of a six-axes arm and interchangeable end-effectors or "hands," a computer with user-friendly software, and a vision tracking system. The facility would serve as the focal point for combining robotics hardware, algorithms, software, sensors, and control systems. Leon Davis, a development engineer and electrical lead for the Robotic Control Systems, said of the new system, "This is not a manipulator that is teleoperated by a man, but a robot with a computer brain capable of memorizing the contours and panels of its intended subject and carrying out its functions autonomously." Because NASA would be asking KSC to design processing facilities for new-generation launch vehicles such as the second generation Space Shuttle and the heavy lift launch vehicles, KSC would need these state-of-the-art robotics to provide the most efficient and effective processing methods. Hazardous, time critical, and repetitive Space Shuttle and payload operations all had potential uses for robotics.
A special feature of the system was a "real time" tracking system using "closed-loop" responsive adaptive control commands, feedback, and error signals. "Adaptive control" meant that the robot altered its path automatically in response to sensory feedback from its environment. The KSC robot's servo-controls and software utilities would allow its arm to operate adaptively to control positions and orientation of all six axes, not only the end-effector as found in standard applications.
An electrically driven, servo-controlled robot had several advantages over hydraulic robots, the major one being that smooth motion, speed, and trajectory controls were possible when the robot handled loads up to 200 lb. As Davis said, "We really don't have applications for hydraulic robots. Hydraulic robots can leak, proving a potential hazard to the tile and other sensitive areas of the orbiter." KSC's robotics research would progress in four phases: phase one was the development of the robotic arm in static work cells; phase two proposed advancing the robotic capabilities to operate in dynamic work cells; phase three would include off-line programming using 3-D graphics and simulated work cells; and phase four entertained the possibility of employing artificial intelligence. Possible future capabilities of robots were three-dimensional scanning; higher order processing; artificial intelligence; sonic, laser, and other ranging systems; and "touch" and mobility systems. (Spaceport News, Nov 7/85, 6)
Scientists analyzing data recently sent from two monitoring devices aboard the Nimbus-7 satellite said the observations confirmed a progressive deterioration in the earth's ozone layer above Antarctica, the NY Times reported. Since 1974, the satellite data showed that a "hole" appeared each October in the ozone layer there, meaning the layer in that area became less able to shield the earth from damaging solar ultraviolet rays. This had caused scientists to predict that increased atmospheric pollution was causing the gradual depletion of stratospheric ozone; the new data seemed to show researchers that the ozone loss was proceeding much faster than expected.
However, Goddard Space Flight Center's Dr. Donald Heath, who had monitored the satellite recordings for several years, said he was uncertain of the reason for the ozone decline. In addition to the theory that fluorocarbons caused ozone depletion, some scientists blamed the depletion on the sulfur compounds and other particles ejected into the stratosphere in the 1982 eruption of El Chichon in Mexico. And Heath said there were other possible explanations, such as the sunspot cycle, which was then near a minimum. According to a study by NASA scientists, the chemical reactions that produced stratospheric ozone were stimulated by a form of ultraviolet radiation that became weak when sunspots were fewest.
Even under normal conditions the ozone layer was subject to wide variations, so it was difficult to establish that the recent depletion was part of a long-term trend. Heath also pointed out that it was not clear whether the Antarctic readings manifested a local change in atmospheric circulation or a global depletion, since the condition of the winter atmosphere over Antarctic was unique.
Government officials in 1977 imposed a ban on fluorocarbons as spray-can propellants, but it became evident that the ozone varied in response to a variety of interacting natural and human influences. By 1984 a National Academy of Science report estimated fluorocarbon-caused ozone reduction at only 2 to 4%. (NYT, Nov 7/85, B21)
The Naval Research Laboratory (NRL), Washington, D.C., announced its scientists devised a precise timing system that used highly efficient and relatively small hydrogen maser clocks that the laboratory expected would enhance timing in the Navstar Global Positioning System (GPS).
GPS, a navigational system based on synchronized clocks (accurate to billionths of a second), would permit users to pinpoint their position within a 30-foot radius by measuring differences in the arrival times of radio signals received from Navstar's satellites. And GPS would disseminate the Naval Observatory's master clock time to fleet units for their command, control, communications, and intelligence.
Maser clocks were considered the most accurate clocks available; however their bulky size and weight (lighter ones weighed over 500 lb.) prevented their use aboard GPS satellites. Also, the massive, tuned cavity where the maser action took place required temperature control and magnetic shielding, which made masers impractical for use in satellites.
The research team at NRL led by Ron Beard reduced the size of maser clocks by a factor of 16 and their weight to 50 lb. And by making the cavity smaller, using different resonant structures, and dielectric (sapphire) loading to produce the effect of a larger cavity, NRL "passive" masers (so called because they did not oscillate on their own) proved to be as accurate as the larger versions. Beard noted that NRL's involvement with masers and the subsequent idea to reduce cavity size came about only after two astro-industrial companies were unsuccessful in meeting GPS's timing demands.
NRL built and tested two experimental maser development models and two advanced development models. An additional NRL project with Hughes Research Laboratories used a Q-multiplier approach to offset the inherently higher signal losses in small cavities.
Research in the NRL maser program included advances in small loaded-cavity properties, beam optics, dissociator reliability, quadropole state selection, thermal/mechanical design, magnetic shielding/design, and vacuum design for space applications.
The NRL-developed technology formed the basis for a $12 million contract awarded to Hughes Aircraft Corp. to produce two types of engineering development models of hydrogen-maser clocks. One clock type was for use in satellites; the other, for GPS ground stations and possibly ships. (NRL Release 58-85R)
The Senate Appropriations Committee cut the Air Force FY 86 request for development of the advanced tactical fighter (ATF) by $103 million to $140 million and recommended that a unit cost cap be put on the program, Defense Daily reported. The House Appropriations Committee earlier approved $170 million for ATF.
Acting on the recommendation of its defense subcommittee, the Senate committee allocated $100 million for the joint advanced fighter engine development program, $13 million for avionics development, and $27 million for continuation of the competitive air vehicle demonstration and validation "for not less than three contractors." Although the committee endorsed the ATF development program "as a long-term counter to Soviet tactical air improvements," it said it "is concerned that the current program does not provide sufficient time to absorb all of the technology" to be incorporated in the aircraft and that the program "entails unacceptable risks." And the committee pointed out that "these advanced technologies would be very expensive to obtain." The Air Force estimated R & D costs for the ATF at $11.8 billion in FY 85 dollars and, after considering a figure up to $40 million, assumed the purchase price would be $35 million in FY 85 dollars. However, the committee pointed out that the Air Force "has not identified how it will reduce ATF costs without deleting technical features previously identified as aircraft requirements." Therefore, the committee directed the Air Force to submit an annual report on the future likely cost of ATF, beginning with the FY 87 budget. It recommended that "a 20% limit be placed on the ATF program unit flyaway costs" above F-15 costs and that this limit be made the baseline of the ATF development program.
The ATF would include sustained supersonic dash, internal weapons carriage, blended aerodynamic design including low observable (stealth) technology, and higher thrust (32,000 lb.) engines. It would also have short takeoff and landing (STOL) capabilities, high transonic and supersonic maneuverability, an expanded flight envelope, and improved survivability. (D/D, Nov 7/85, 33)
United Airlines today placed orders with a value of over $3.1 billion for up to 110 737-300s and up to six 747s, the largest order ever placed by an airline, Aviation Daily reported. The previous record was a November 12, 1980, order by Delta for 60 757s valued at $3 billion.
United President James Hartigan said that the first two 737s and two 747- 200Bs had a June 1988 delivery date and that "we have obtained flexibility in the contracts to change the downline delivery dates of the later aircraft to meet our needs." He added that the orders were made possible because "we reached cost-competitive contracts with all of our work groups. We are now positioned properly for dramatic growth in the competitive marketplace." All aircraft should be delivered by the end of 1990, giving United a fleet of 478 transports. (A/D, Nov 8/85, 41)
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