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Anderson, K.

Publications and source records attributed to Anderson, K..

31 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Effects of spaceflight conditions on fertilization and embryogenesis in the sea urchin Lytechinus pictus

Calcium loss and muscle atrophy are two of the main metabolic changes experienced by astronauts and crew members during exposure to microgravity in space. Calcium and cytoskeletal events were investigated within sea urchin embryos which were cultured in space under both microgravity and 1 g conditions. Embryos were fixed at time-points ranging from 3 h to 8 days after fertilization. Investigative emphasis was placed upon: (1) sperm-induced calcium-dependent exocytosis and cortical granule secretion, (2) membrane fusion of cortical granule and plasma membranes; (3) microfilament polymerization and microvilli elongation; and (5) embryonic development into morula, blastula, gastrula, and pluteus stages. For embryos cultured under microgravity conditions, the processes of cortical granule discharge, fusion of cortical granule membranes with the plasma membrane, elongation of microvilli and elevation of the fertilization coat were reduced in comparison with embryos cultured at 1 g in space and under normal conditions on Earth. Also, 4% of all cells undergoing division in microgravity showed abnormalities in the centrosome-centriole complex. These abnormalities were not observed within the 1 g flight and ground control specimens, indicating that significant alterations in sea urchin development processes occur under microgravity conditions. Copyright 1999 Academic Press.

STS-77 Shuttle Project↗
NASA NTRS1989

Design and implementation of components for a bioregenerative system for growing higher order plants in space

This report summarizes the efforts of the NASA/USRA Advanced Design Program during the 1988-89 scholastic year. The primary goal was to address specific needs in the design of an integrated system to grow higher order plants in space. The initial phase of the design effort concentrated on studying such a system and identifying its needs. Once these needs were defined, emphasis was placed on the design and fabrication of devices to meet them. Specific attention was placed on a hand-held harvester, a nutrient concentration sensor, an air-water separator, and a closed-loop biological system simulation.

Brakman, B.↗
NASA NTRS1989

Lunar shuttle

Current plans for the extension of human presence into the solar system include the establishment of a permanently occupied base on the Moon for use as a source of raw materials, a transportation node, a facility for the fabrication and launch of elements of the space exploration infrastructure, and a base for scientific investigation and astronomical observatories. All of the aforementioned uses of a lunar base foresee the requirement for a lunar shuttle to operate from the lunar surface to one or more orbiting space stations located in low lunar orbits (LLO). The Utah State University lunar shuttle design is baslined for implementation after a mature lunar base has been established. The shuttle is designed to operate between the lunar base and a space station located in a 400-km-altitude orbit. This orbit was chosen with reference to Apollo experience, which has indicated that very low orbits, on the order of 100-km, may be unstable over periods of many months. After a thorough investigation of the anticipated needs and production capabilities of a lunar base, several design requirements were placed upon the shuttle. These requirements are (1) maximum use of lunar-derived propellant; (2) modularity and payload versatility; (3) two-way transport of 25-metric-ton cargo; (4) human transport capability; (5) satellite servicing; and (6) 3000-kg mass budget.

Voyer, P.↗
NASA NTRS1985

Judgments of natural and anomalous trajectories in the presence and absence of motion

Three experiments using McCloskey's curved tube problem, in which people are asked to predict the path that a ball takes when it is shot through a tube curved in a 'C' or spiral, are reported. The first experiment compared the perceptual and representational competencies of observers in recognizing the natural trajectory of the ball, and the second examined the competencies of children on this problem. The third experiment attempted to enhance the representational competence of observers by encouraging them to use a mental imagery approach to the problem. The subjects were presented with both on-going events and with static representations of the event. Men performed better than women under both these conditions, a result not attributable to formal instruction in physics. Children showed no gender effect. The use of mental imagery did not enhance performance on the static test.

Kaiser, M. K.↗
NASA NTRS1983

Association between gradual hard X-ray emission and metric continua during large flares

X-ray radiation is used to study coronal phenomena in conjunction with meter wave observations during some large solar flares. It is found that metric flare continua and moving type IV bursts are associated with gradual and long lasting (a few tens of minutes) microwave and hard X-ray emissions. The detailed temporal analysis reveals that although metric and hard X-ray sources are located at very different heights, both kinds of emission result from a common and continuous/repetitive injection of electrons in the corona. The late part of the metric event (stationary type IV burst) is only associated with soft X-ray radiation. This indicates that the mean energy of the radiating electrons is lower during stationary type IV bursts than during the earlier parts of the event.

Klein, L.↗
NASA NTRS1982

Mars Orbiter Study. Volume 1: Summary

Spacecraft system and subsystem designs were developed at the conceptual level to perform either of two Mars orbiter missions, a climatology mission and an aeronomy mission. The HS 376 spacecraft is the basis for the design because it has the lowest cost due to its production line status. The mission design, science instrument accommodation, and spacecraft design are summarized.

Drean, R.↗
NASA NTRS1981

The Viking seismometry

Efforts were made to determine the seismicity of Mars as well as define its internal structure by detecting vibrations generated by marsquakes and meteoroid impacts. The lack of marsquakes recognized in the Viking data made it impossible to make any direct inferences about the interior of Mars and only allowed the setting of upper bounds on the seismic activity of the planet. After obtaining more than 2100 hours worth of data during the quite periods at rates of one sample per second or higher, the Viking 2 seismometer was turned off as a consequence of a landing system failure. During the periods when adequate data were obtained, one event of possible seismic or meteoroid impact origin was recognized; however, there is a significant probability that this event was generated by a wind gust.

Lazarewicz, A. R.↗
NASA NTRS1972

Lunar crust - Structure and composition.

Lunar seismic data from artificial impacts recorded at three Apollo seismometers are interpreted to determine the structure of the moon's interior to a depth of about 100 kilometers. In the Fra Mauro region of Oceanus Procellarum, the moon has a layered crust 65 kilometers thick. The seismic velocities in the upper 25 kilometers are consistent with those in lunar basalts. Between 25 and 65 kilometers., the nearly constant velocity (6.8 kilometers per second) corresponds to velocities in gabbroic and anorthositic rocks. The apparent velocity is high (about 9 kilometers per second) in the lunar mantle immediately below the crust.

Toksoz, M. N.↗
NASA NTRS1972

The X-ray spectrum of NGC 5128.

Evaluation of the X-ray spectrum of NGC 5128 (Cen A) obtained by sounding rocket and balloon observations in the range from 1 to 180 keV. NGC 5128 may be fitted by a power law with a photon index -2 less than or equal to n less than or equal to -1.45. Inverse Compton models are presented, and constraints on their parameters are discussed. In all such models, the electrons and magnetic field have not yet equilibrated. Alternatively, the X rays may originate in a compact central core source.

Lampton, M.↗
NASA NTRS1972

Structure, composition, and properties of lunar crust.

Lunar seismic data from three Apollo seismometers are interpreted to determine the structure of the moon's interior to a depth of about 100 km. The travel times and amplitudes of P and S arrivals from Saturn IV-B and LM impacts are interpreted in terms of a velocity profile. The most outstanding feature of the model is that, in the Fra Mauro region of Oceanus Procellarum, the moon has a 65 km-thick layered crust. Other features of the model are: (1) rapid increase of velocity near the surface due to pressure effects on dry rocks, (2) a discontinuity at a depth of about 25 km, (3) near-constant velocities between 25 and 65 km deep, (4) a major discontinuity at 65 km marking the base of the lunar crust, and (5) very high apparent velocities (about 9 km/sec for P waves) in the lunar mantle below the crust.

Toksoz, M. N.↗
NASA NTRS1971

Beam lead technology

Beam lead technology for microcircuit interconnections with applications to metallization, passivation, and bonding

Anderson, K.↗