NASA future mission needs and benefits of controls-structures interaction technology

Two questions are addressed: (1) which future missions need Controls-Structures Interaction (CSI) technology for implementing large spacecraft in orbit; and (2) what specific benefits are to be derived if the technology is available? The answers to these questions were used to help formulate and direct the CSI technology development program. Many future NASA missions have common CSI technology needs which can best be developed in a broad-based, but focused, technology program to provide the greatest benefit to the largest number of users. Three CSI benefit studies were completed to date as part of ongoing assessment process: (1) missions requiring large antennas; (2) missions requiring large optical systems; and (3) missions requiring the use of closed-loop controlled, flexible, remote manipulator systems (RMS) for in-space assembly. The large antenna and flexible RMS mission benefits are discussed

A summary of the Skylab crew/vehicle disturbances experiment T-013

A manned space flight experiment (designated experiment T-013) to assess the characteristics of astronaut crew-motion disturbances was conducted on the second manned Skylab mission. A brief description of the experiment hardware utilized is given, and a comprehensive discussion of the experiment data reduction and analysis is presented. Data obtained from a force-measuring system, an astronaut limb-motion measuring system, motion-picture film, and the Skylab attitude and pointing control system is described. Results show that astronaut crew members can produce significant disturbance inputs to a spacecraft's attitude control system. Total forces of up to 400 N were exerted during vigorous soaring activities, whereas ""restrained'' motions by the experiment subject generated total forces of up to 300 N. A discussion of potential applications of the experiment results is given and appendixes provide additional detail with respect to experiment operations and results

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 324)

This bibliography lists 200 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during May, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

Part 1: a process view of nature. Multifunctional integration and the role of the construction agent

This is the first of two linked articles which draw s on emerging understanding in the field of biology and seeks to communicate it to those of construction, engineering and design. Its insight is that nature 'works' at the process level, where neither function nor form are distinctions, and materialisation is both the act of negotiating limited resource and encoding matter as 'memory', to sustain and integrate processes through time. It explores how biological agents derive work by creating 'interfaces' between adjacent locations as membranes, through feedback. Through the tension between simultaneous aggregation and disaggregation of matter by agents with opposing objectives, many functions are integrated into an interface as it unfolds. Significantly, biological agents induce flow and counterflow conditions within biological interfaces, by inducing phase transition responses in the matte r or energy passing through them, driving steep gradients from weak potentials (i.e. shorter distances and larger surfaces). As with biological agents, computing, programming and, increasingly digital sensor and effector technologies share the same 'agency' and are thus convergent

Solar array study for solar electric propulsion spacecraft for the Encke rendezvous mission

The work is described which was performed on the design, analysis and performance of a 20 kW rollup solar array capable of meeting the design requirements of a solar electric spacecraft for the 1980 Encke rendezvous mission. To meet the high power requirements of the proposed electric propulsion mission, solar arrays on the order of 186.6 sq m were defined. Because of the large weights involved with arrays of this size, consideration of array configurations is limited to lightweight, large area concepts with maximum power-to-weight ratios. Items covered include solar array requirements and constraints, array concept selection and rationale, structural and electrical design considerations, and reliability considerations

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program 1988, volume 1

The 1988 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by the University of Houston and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began in 1965 at JSC and in 1964 nationally, are (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objectives of the NASA Centers

Modeling Operator Behavior in the Safety Analysis of Collaborative Robotic Applications

Human-Robot Collaboration is increasingly prominent in peo- ple's lives and in the industrial domain, for example in manufacturing applications. The close proximity and frequent physical contacts between humans and robots in such applications make guaranteeing suitable levels of safety for human operators of the utmost importance. Formal veri- cation techniques can help in this regard through the exhaustive explo- ration of system models, which can identify unwanted situations early in the development process. This work extends our SAFER-HRC method- ology with a rich non-deterministic formal model of operator behaviors, which captures the hazardous situations resulting from human errors. The model allows safety engineers to rene their designs until all plausi- ble erroneous behaviors are considered and mitigated

A longer isoform of Stim1 is a negative SOCE regulator but increases cAMP-modulated NFAT signaling

Alternative splicing is a potent modifier of protein function. Stro mal interaction molecule 1 (Stim1) is the essential activator of store-operated Ca2+ entry (SOCE) triggering activation of transcrip tion factors. Here, we characterize Stim1A, a splice variant with an additional 31 amino acid domain inserted in frame within its cytosolic domain. Prominent expression of exon A is found in astro cytes, heart, kidney, and testes. Full-length Stim1A functions as a dominant-negative regulator of SOCE and ICRAC, facilitating sequence-specific fast calcium-dependent inactivation and desta bilizing gating of Orai channels. Downregulation or absence of native Stim1A results in increased SOCE. Despite reducing SOCE, Stim1A leads to increased NFAT translocation. Differential proteo mics revealed an interference of Stim1A with the cAMP-SOCE crosstalk by altered modulation of phosphodiesterase 8 (PDE8), resulting in reduced cAMP degradation and increased PIP5K activ ity, facilitating NFAT activation. Our study uncovers a hitherto unknown mechanism regulating NFAT activation and indicates that cell-type-specific splicing of Stim1 is a potent means to regu late the NFAT signalosome and cAMP-SOCE crosstalk