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Sample records for reef health pathfinder

  1. Quality Health Information on the Internet: Developing a Diabetes Pathfinder for the Chinese Population

    PubMed Central

    Cleveland, Ana D.; Philbrick, Jodi; Pan, Xuequn (Della); Yu, Xinyu; Chen, Jiangping; O'Neill, Marty; Smith, Lisa

    2010-01-01

    A Web-based bilingual diabetes information pathfinder was created to help the Chinese population access quality health information on the Internet as part of a collaborative outreach project in the Dallas-Fort Worth area. A survey was conducted to identify the demographics, Internet usage, health information needs, and preferences for training sessions of the Chinese population. Breast cancer, diabetes, and breast cancer were the top three diseases of interest. The process of developing the pathfinder is described from start to finish, and it can serve as a model for the development of others. Pathfinder training sessions were held. PMID:20526379

  2. Quality Health Information on the Internet: Developing a Diabetes Pathfinder for the Chinese Population.

    PubMed

    Cleveland, Ana D; Philbrick, Jodi; Pan, Xuequn Della; Yu, Xinyu; Chen, Jiangping; O'Neill, Marty; Smith, Lisa

    2009-10-01

    A Web-based bilingual diabetes information pathfinder was created to help the Chinese population access quality health information on the Internet as part of a collaborative outreach project in the Dallas-Fort Worth area. A survey was conducted to identify the demographics, Internet usage, health information needs, and preferences for training sessions of the Chinese population. Breast cancer, diabetes, and breast cancer were the top three diseases of interest. The process of developing the pathfinder is described from start to finish, and it can serve as a model for the development of others. Pathfinder training sessions were held. PMID:20526379

  3. Pathfinder-Plus on flight in Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  4. Pathfinder-Plus on flight over Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    ,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  5. Pathfinder-Plus on flight over Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    ,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  6. Pathfinder-Plus on a flight in Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  7. Pathfinder-Plus takes off on flight in Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  8. Pathfinder-Plus on flight over Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    1998-01-01

    days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  9. Research Spotlight: New method to assess coral reef health

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-03-01

    Coral reefs around the world are becoming stressed due to rising temperatures, ocean acidification, overfishing, and other factors. Measuring community level rates of photosynthesis, respiration, and biogenic calcification is essential to assessing the health of coral reef ecosystems because the balance between these processes determines the potential for reef growth and the export of carbon. Measurements of biological productivity have typically been made by tracing changes in dissolved oxygen in seawater as it passes over a reef. However, this is a labor-intensive and difficult method, requiring repeated measurements. (Geophysical Research Letters, doi:10.1029/2010GL046179, 2011)

  10. Coral health on reefs near mining sites in New Caledonia.

    PubMed

    Heintz, T; Haapkylä, J; Gilbert, A

    2015-07-23

    Coral health data are poorly documented in New Caledonia, particularly from reefs chronically subject to anthropogenic and natural runoff. We investigated patterns of coral disease and non-disease conditions on reefs situated downstream of mining sites off the coast of New Caledonia. Surveys were conducted in March 2013 at 2 locations along the west coast and 2 locations along the east coast of the main island. Only 2 coral diseases were detected: growth anomalies and white syndrome. The most prevalent signs of compromised health at each location were sediment damage and algal overgrowth. These results support earlier findings that sedimentation and turbidity are major threats to in-shore reefs in New Caledonia. The Poritidae-dominated west coast locations were more subject to sediment damage, algal overgrowth and growth anomalies compared to the Acroporidae-dominated east coast locations. If growth form and resistance of coral hosts influence these results, differences in environmental conditions including hydro-dynamism between locations may also contribute to these outputs. Our results highlight the importance of combining coral health surveys with measurements of coral cover when assessing the health status of a reef, as reefs with high coral cover may have a high prevalence of corals demonstrating signs of compromised health. PMID:26203888

  11. Pathfinder-Plus on a flight over Hawaiian island N'ihau

    NASA Technical Reports Server (NTRS)

    1998-01-01

    -stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  12. Pathfinder-Plus on flight over Hawaiian island N'ihau

    NASA Technical Reports Server (NTRS)

    1998-01-01

    -stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  13. Pathfinder-Plus on flight near Hawaiian island N'ihau

    NASA Technical Reports Server (NTRS)

    1998-01-01

    flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  14. French Frigate Shoals reef health survey

    USGS Publications Warehouse

    Work, Thierry M.; Coles, Steve L.; Rameyer, Robert

    2002-01-01

    French Frigate Shoals consists of a large (31 nm) fringing reef partially enclosing a lagoon. A basalt pinnacle (La Perouse Pinnacle) arises approximately halfway between the two ends of the arcs of the fringing reefs. Tern Island is situated at the northern end of the lagoon and is surrounded by a dredged ship channel. The lagoon becomes progressively shallower from west to east and harbors a variety of marine life including corals, fish, marine mammals, and sea turtles (Amerson 1971). In 2000, an interagency survey of the northwestern Hawaiian Islands was done to document the fauna and flora in FFS (Maragos and Gulko, 2002). During that survey, 38 stations were examined, and 41 species of stony corals were documented, the most of any of the NW Hawaiian islands (Maragos and Gulko 2002). In some of these stations, corals with abnormalities were observed. The present study aimed to expand on the 2000 survey to evaluate the lesions in areas where they were documented.

  15. TEMPORAL TRENDS IN THE HEALTH OF SOUTH FLORIDA CORAL REEFS

    EPA Science Inventory

    Barron, M.G., D.L. Santavy, L. MacLaughlin, E. Mueller, E. Peters, B. Quarles and J. Campbell. In press. Temporal Trends in the Health of South Florida Coral Reefs (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November 2004, Portland, OR. 1 p. (ERL,GB R100...

  16. Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background

    NASA Technical Reports Server (NTRS)

    1998-01-01

    and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

  17. LISA Pathfinder

    NASA Technical Reports Server (NTRS)

    Stebbins, Robin

    2008-01-01

    USA Pathfinder is a space mission dedicated to demonstrating technology for the Laser Interferometer Space Antenna (LISA). LISA is a joint ESA/NASA mission to detect low-frequency gravitational waves on the 0.0001 to 0.1 Hz frequency band. LISA is expected to observe 100's of merging massive black hole binaries out z-15, tens of thousands of close compact binary systems in the Milky Way, merging intermediate-mass black hole binaries, tens of stellar-mass black holes falling into supermassive black holes in galactic centers, and possibly other exotic sources. Several critical LISA technologies have not been demonstrated at the requisite level of performance. In spaceflight, and some fight hardware cannot be tested in a 1-g environment. Hence, the LISA Pathfinder mission is being implemented to demonstrate these critical LISA technologies in a relevant flight environment. LISA Pathfinder mimics one arm of the LISA constellation by shrinking the 5-million-kilometer armlength down to a few tens of centimeters. The experimental concept is to measure the relative separation between two test masses nominally following their own geodesics, and thereby determine the relative residual acceleration between them near 1 mHz, about a decade above the lowest frequency required by LISA. To implement such a concept, disturbances on the test masses must be kept very small by many design features, but chiefly by "drag-free" flight. A drag-free spacecraft follows a free-falling test mass which it encloses, but has no mechanical connection to. The spacecraft senses it's orientation and separation with respect to the proof mass, and its propulsion system is commanded to keep the spacecraft centered about the test mass. Thus, the spacecraft shields the test mass from most external influences, and minimizes the effect of force gradients arising from the spacecraft, and acting on the test mass. LISA Pathfinder will compare the geodesic of one test mass against that of the other. Only a

  18. Environmental quality and preservation; reefs, corals, and carbonate sands; guides to reef-ecosystem health and environment

    USGS Publications Warehouse

    Lidz, Barbara H.

    2001-01-01

    Introduction In recent years, the health of the entire coral reef ecosystem that lines the outer shelf off the Florida Keys has declined markedly. In particular, loss of those coral species that are the building blocks of solid reef framework has significant negative implications for economic vitality of the region. What are the reasons for this decline? Is it due to natural change, or are human activities (recreational diving, ship groundings, farmland runoff, nutrient influx, air-borne contaminants, groundwater pollutants) a contributing factor and if so, to what extent? At risk of loss are biologic resources of the reefs, including habitats for endangered species in shoreline mangroves, productive marine and wetland nurseries, and economic fisheries. A healthy reef ecosystem builds a protective offshore barrier to catastrophic wave action and storm surges generated by tropical storms and hurricanes. In turn, a healthy reef protects the homes, marinas, and infrastructure on the Florida Keys that have been designed to capture a lucrative tourism industry. A healthy reef ecosystem also protects inland agricultural and livestock areas of South Florida whose produce and meat feed much of the United States and other parts of the world. In cooperation with the National Oceanic and Atmospheric Administration's (NOAA) National Marine Sanctuary Program, the U.S. Geological Survey (USGS) continues longterm investigations of factors that may affect Florida's reefs. One of the first steps in distinguishing between natural change and the effects of human activities, however, is to determine how coral reefs have responded to past environmental change, before the advent of man. By so doing, accurate scientific information becomes available for Marine Sanctuary management to understand natural change and thus to assess and regulate potential human impact better. The USGS studies described here evaluate the distribution (location) and historic vitality (thickness) of Holocene

  19. New mapping techniques help assess the health of Hawaii's coral reefs

    USGS Publications Warehouse

    Field, M.E.; Chavez, P.S., Jr.; Evans, K.R.; Cochran, S.A.

    2001-01-01

    The U.S. Geological Survey (USGS) is working closely with academic institutions and state and Federal agencies to assess the factors that affect the health of Hawaii's and our Nation's coral reefs. In order to establish a basis from which scientists can objectively detect changes in reef health, the USGS and its cooperators are applying many new techniques to the mapping and monitoring of coral reefs in Hawaii.

  20. Turning science into health solutions: KEMRI’s challenges as Kenya’s health product pathfinder

    PubMed Central

    2010-01-01

    Background A traditional pathway for developing new health products begins with public research institutes generating new knowledge, and ends with the private sector translating this knowledge into new ventures. But while public research institutes are key drivers of basic research in sub-Saharan Africa, the private sector is inadequately prepared to commercialize ideas that emerge from these institutes, resulting in these institutes taking on the role of product development themselves to alleviate the local disease burden. In this article, the case study method is used to analyze the experience of one such public research institute: the Kenya Medical Research Institute (KEMRI). Discussion Our analysis indicates that KEMRI’s product development efforts began modestly, and a manufacturing facility was constructed with a strategy for the facility’s product output which was not very successful. The intended products, HIV and Hepatitis B diagnostic kits, had a short product life cycle, and an abrupt change in regulatory requirements left KEMRI with an inactive facility. These problems were the result of poor innovation management capacity, variability in domestic markets, lack of capital to scale up technologies, and an institutional culture that lacked innovation as a priority. However, KEMRI appears to have adapted by diversifying its product line to mitigate risk and ensure continued use of its manufacturing facility. It adopted an open innovation business model which linked it with investors, research partnerships, licensing opportunities, and revenue from contract manufacturing. Other activities that KEMRI has put in place over several years to enhance product development include the establishment of a marketing division, development of an institutional IP policy, and training of its scientists on innovation management. Summary KEMRI faced many challenges in its attempt at health product development, including shifting markets, lack of infrastructure

  1. Spectrographic imaging: A bird's-eye view of the health of coral reefs

    NASA Astrophysics Data System (ADS)

    Mumby, Peter J.; Chisholm, John R. M.; Clark, Chris D.; Hedley, John D.; Jaubert, Jean

    2001-09-01

    Almost three-quarters of the world's coral reefs are thought to be deteriorating as a consequence of environmental stress. Until now, it has been possible to evaluate reef health only by field survey, which is labour-intensive and time-consuming. Here we map live coral cover from the air by remote imaging, a technique that will enable the state of shallow reefs to be monitored swiftly and over large areas.

  2. DECIGO pathfinder

    NASA Astrophysics Data System (ADS)

    Ando, M.; Kawamura, S.; Nakamura, T.; Tsubono, K.; Tanaka, T.; Funaki, I.; Seto, N.; Numata, K.; Sato, S.; Ioka, K.; Kanda, N.; Takashima, T.; Agatsuma, K.; Akutsu, T.; Akutsu, T.; Aoyanagi, K.-s.; Arai, K.; Arase, Y.; Araya, A.; Asada, H.; Aso, Y.; Chiba, T.; Ebisuzaki, T.; Enoki, M.; Eriguchi, Y.; Fujimoto, M.-K.; Fujita, R.; Fukushima, M.; Futamase, T.; Ganzu, K.; Harada, T.; Hashimoto, T.; Hayama, K.; Hikida, W.; Himemoto, Y.; Hirabayashi, H.; Hiramatsu, T.; Hong, F.-L.; Horisawa, H.; Hosokawa, M.; Ichiki, K.; Ikegami, T.; Inoue, K. T.; Ishidoshiro, K.; Ishihara, H.; Ishikawa, T.; Ishizaki, H.; Ito, H.; Itoh, Y.; Kamagasako, S.; Kawashima, N.; Kawazoe, F.; Kirihara, H.; Kishimoto, N.; Kiuchi, K.; Kobayashi, S.; Kohri, K.; Koizumi, H.; Koima, Y.; Kokeyama, K.; W-Kokuyama; Kotake, K.; Kozai, Y.; Kudoh, H.; Kunimori, H.; Kuninaka, H.; Kuroda, K.; Maeda, K.-i.; Matsuhara, H.; Mino, Y.; Miyakawa, O.; Miyoki, S.; Morimoto, M. Y.; Morioka, T.; Morisawa, T.; Moriwaki, S.; Mukohyama, S.; Musha, M.; Nagano, S.; Naito, I.; Nakagawa, N.; Nakamura, K.; Nakano, H.; Nakao, K.; Nakasuka, S.; Nakayama, Y.; Nishida, E.; Nishiyama, K.; Nishizawa, A.; Niwa, Y.; Ohashi, M.; Ohishi, N.; Ohkawa, M.; Okutomi, A.; Onozato, K.; Oohara, K.; Sago, N.; Saijo, M.; Sakagami, M.; Sakai, S.-i.; Sakata, S.; Sasaki, M.; Sato, T.; Shibata, M.; Shinkai, H.; Somiya, K.; Sotani, H.; Sugiyama, N.; Suwa, Y.; Tagoshi, H.; Takahashi, K.; Takahashi, K.; Takahashi, T.; Takahashi, H.; Takahashi, R.; Takahashi, R.; Takamori, A.; Takano, T.; Taniguchi, K.; Taruya, A.; Tashiro, H.; Tokuda, M.; Tokunari, M.; Toyoshima, M.; Tsujikawa, S.; Tsunesada, Y.; Ueda, K.-i.; Utashima, M.; Yamakawa, H.; Yamamoto, K.; Yamazaki, T.; Yokoyama, J.; Yoo, C.-M.; Yoshida, S.; Yoshino, T.

    2008-07-01

    DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article.

  3. Coastal nutrification and coral health at Porto Seguro reefs, Brazil

    NASA Astrophysics Data System (ADS)

    Costa, O.; Attrill, M.; Nimmo, M.

    2003-04-01

    Human activities have substantially increased the natural flux of nutrients to coastal systems worldwide. In Brazilian reefs, all major stresses (sedimentation, overfishing, tourism-related activities and nutrification) are human induced. To assess nutrification levels in Brazilian coastal reefs, measurements of the distribution patterns of nutrients and chlorophyll concentrations were conducted in three nearshore and offshore reefs with distinct nutrient inputs along the south coast of Bahia State. Seawater and porewater samples were analysed for soluble reactive phosphorus, total oxidised nitrogen and reactive silica. Benthic surveys were performed at all sites to investigate the relationships between benthic community composition and nutrient and chlorophyll concentrations. Sampling was undertaken in dry and rainy seasons. Results of both seawater and porewater nutrient measurements revealed the occurrence of consistent spatial and temporal patterns. An inshore-offshore gradient reflects the occurrence of land-based point sources, with significant amount of nutrients being delivered by human activities on the coast (untreated sewage and groundwater seepage). Another spatial gradient is related to distance from a localized source of pollution (an urban settlement without sewerage treatment) with two nearshore reefs presenting distinct nutrient and chlorophyll concentrations. Seasonal variations suggest that submarine groundwater discharge (SGD) is the primary source of nutrients for the coastal reefs during rainy season. The data also suggests that the SGD effect is not restricted to nearshore reefs, and may be an important factor controlling the differences between landward and seaward sides on the offshore reef. Benthic community assessment revealed that turf alga is the dominant group in all studied reefs and that zoanthids are the organisms most adapted to take advantage of nutrient increase in coastal areas. At nearshore reefs, there was a negative

  4. Pathfinders: A Self-Care and Health Education Program for Older Widows and Widowers.

    ERIC Educational Resources Information Center

    Caserta, Michael S.; Lund, Dale A.; Rice, Sarah Jane

    1999-01-01

    Describes a research-based self-care health education program for recently widowed people. Program aims to provide a foundation of knowledge, motivation, and encouragement to initiate positive behavioral changes, and to establish a support network. Preliminary analysis suggests the program is achieving many of the intended outcomes. (Author/JDM)

  5. Abrolhos bank reef health evaluated by means of water quality, microbial diversity, benthic cover, and fish biomass data.

    PubMed

    Bruce, Thiago; Meirelles, Pedro M; Garcia, Gizele; Paranhos, Rodolfo; Rezende, Carlos E; de Moura, Rodrigo L; Filho, Ronaldo-Francini; Coni, Ericka O C; Vasconcelos, Ana Tereza; Amado Filho, Gilberto; Hatay, Mark; Schmieder, Robert; Edwards, Robert; Dinsdale, Elizabeth; Thompson, Fabiano L

    2012-01-01

    The health of the coral reefs of the Abrolhos Bank (Southwestern Atlantic) was characterized with a holistic approach using measurements of four ecosystem components: (i) inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv) microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California) were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste) and one legally protected but poorly enforced coastal reef (the "paper park" of Timbebas Reef). The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes) showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic microbial pathogens

  6. Abrolhos Bank Reef Health Evaluated by Means of Water Quality, Microbial Diversity, Benthic Cover, and Fish Biomass Data

    PubMed Central

    Bruce, Thiago; Meirelles, Pedro M.; Garcia, Gizele; Paranhos, Rodolfo; Rezende, Carlos E.; de Moura, Rodrigo L.; Filho, Ronaldo-Francini; Coni, Ericka O. C.; Vasconcelos, Ana Tereza; Amado Filho, Gilberto; Hatay, Mark; Schmieder, Robert; Edwards, Robert; Dinsdale, Elizabeth; Thompson, Fabiano L.

    2012-01-01

    The health of the coral reefs of the Abrolhos Bank (southwestern Atlantic) was characterized with a holistic approach using measurements of four ecosystem components: (i) inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv) microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California) were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste) and one legally protected but poorly enforced coastal reef (the “paper park” of Timbebas Reef). The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes) showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic microbial

  7. Assessment of the Water Quality and Ecosystem Health of the Great Barrier Reef (Australia): Conceptual Models

    NASA Astrophysics Data System (ADS)

    Haynes, David; Brodie, Jon; Waterhouse, Jane; Bainbridge, Zoe; Bass, Deb; Hart, Barry

    2007-12-01

    Run-off containing increased concentrations of sediment, nutrients, and pesticides from land-based anthropogenic activities is a significant influence on water quality and the ecologic conditions of nearshore areas of the Great Barrier Reef World Heritage Area, Australia. The potential and actual impacts of increased pollutant concentrations range from bioaccumulation of contaminants and decreased photosynthetic capacity to major shifts in community structure and health of mangrove, coral reef, and seagrass ecosystems. A detailed conceptual model underpins and illustrates the links between the main anthropogenic pressures or threats (dry-land cattle grazing and intensive sugar cane cropping) and the production of key contaminants or stressors of Great Barrier Reef water quality. The conceptual model also includes longer-term threats to Great Barrier Reef water quality and ecosystem health, such as global climate change, that will potentially confound direct model interrelationships. The model recognises that system-specific attributes, such as monsoonal wind direction, rainfall intensity, and flood plume residence times, will act as system filters to modify the effects of any water-quality system stressor. The model also summarises key ecosystem responses in ecosystem health that can be monitored through indicators at catchment, riverine, and marine scales. Selected indicators include riverine and marine water quality, inshore coral reef and seagrass status, and biota pollutant burdens. These indicators have been adopted as components of a long-term monitoring program to enable assessment of the effectiveness of change in catchment-management practices in improving Great Barrier Reef (and adjacent catchment) water quality under the Queensland and Australian Governments’ Reef Water Quality Protection Plan.

  8. Pathfinder aircraft in flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The unique Pathfinder solar-powered flying wing, is shown during a checkout flight from the Dryden Flight Research Center, Edwards, California. This two-hour low-altitude flight over Rogers Dry Lake, Nov. 19, 1996, served to test aircraft systems and functional procedures, according to officials of AeroVironment, Inc., Pathfinder's developer and operator. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  9. Pathfinder Rear Ramp

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mars Pathfinder's rear rover ramp can be seen successfully unfurled in this image, taken at the end of Sol 2 by the Imager for Mars Pathfinder (IMP). This ramp was later used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. Areas of a lander petal and deflated airbag are visible at left. The image helped Pathfinder scientists determine that the rear ramp was the one to use for rover deployment. At upper right is the rock dubbed 'Barnacle Bill,' which Sojourner will later study.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C.

  10. Pathfinder aircraft flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pathfinder research aircraft's wing structure is clearly defined as it soars under a clear blue sky during a test flight from Dryden Flight Research Center, Edwards, California, in November of 1996. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  11. LISA and its pathfinder

    NASA Astrophysics Data System (ADS)

    The LISA Pathfinder Team

    2015-08-01

    On astronomical scales, gravity is the engine of the Universe. The launch of LISA Pathfinder this year to prepare the technology to detect gravitational waves will help us 'listen' to the whole Universe.

  12. MESUR Pathfinder Science Investigations

    NASA Technical Reports Server (NTRS)

    Golombek, M.

    1993-01-01

    The MESUR (Mars Environmental Survey) Pathfinder mission is the first Discovery mission planned for launch in 1996. MESUR Pathfinder is designed as an engineering demonstration of the entry, descent and landing approach to be employed by the follow-on MESUR Network mission, which will land of order 10 small stations on the surface of Mars to investigate interior, atmospheric and surface properties. Pathfinder is a small Mars lander, equipped with a microrover to deploy instruments and explore the local landing site. Instruments selected for Pathfinder include a surface imager on a 1 m pop-up mast (stereo with spectral filters), an atmospheric structure instrument/surface meteorology package, and an alpha proton x-ray spectrometer. The microrover will carry the alpha proton x-ray spectrometer to a number of different rocks and surface materials and provide close-up imaging...

  13. Pathfinder: Humans in space

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1988-01-01

    Viewgraphs are presented on the Pathfinder program. Information is given on human exploration of the solar system, technical requirements interfaces, program objectives, space suits, human performance, man-machine systems, space habitats, life support systems, and artificial gravity

  14. Pathfinder aircraft in flight

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus

  15. Mapping Health of Bonaire Coral Reefs Using a Lightweight Hyperspectral Mapping System - First Results

    NASA Astrophysics Data System (ADS)

    Suomalainen, Juha; Mucher, Sander; Kooistra, Lammert; Meesters, Erik

    2014-05-01

    The Dutch Caribbean island of Bonaire is one of the world's top diving holiday destinations much due to its clear waters and healthy coral reefs. The coral reefs surround the western side of the island as an approximately 50-150m wide band. However, the general consensus is that the extent and biodiversity of the Bonarian coral reef is constantly decreasing due to anthropogenic pressures. The last extensive study of the health of the reef ecosystem was performed in 1985 by Van Duyl creating an underwater atlas. In order to update this atlas of Bonaire's coral reefs, in October 2013, a hyperspectral mapping campaign was performed using the WUR Hyperspectral Mapping System (HYMSY). A dive validation campaign has been planned for early 2014. The HYMSY consists of a custom pushbroom spectrometer (range 450-950nm, FWHM 9nm, ~20 lines/s, 328 pixels/line), a consumer camera (collecting 16MPix raw image every 2 seconds), a GPS-Inertia Navigation System (GPS-INS), and synchronization and data storage units. The weight of the system at take-off is 2.0kg allowing it to be mounted on varying platforms. In Bonaire the system was flown on two platforms. (1) on a Cessna airplane to provide a coverage for whole west side of the island with a hyperspectral map in 2-4m resolution and a RGB orthomosaic in 15cm resolution, and (2) on a kite pulled by boat and car to provide a subset coverage in higher resolution. In this presentation we will present our mapping technique and first results including a preliminary underwater atlas and conclusions on reef development.

  16. Effects of changing temperatures on coral reef health: Implications for management

    NASA Astrophysics Data System (ADS)

    Selig, Elizabeth Rose

    Human-induced climate change has already led to substantial changes in a variety of ecosystems. Coral reefs are particularly vulnerable to rises in ocean temperature as a result of climate change because they already live near their thermal limits. However, we know little about the spatial patterns of temperature anomalies, areas of greater than usual temperature, which cause coral mortality and increased rates of coral disease. These gaps in knowledge make it difficult to design effective management strategies for mitigating the effects of ocean warming. My dissertation research uses a combination of a new satellite ocean temperature dataset, field surveys on coral health, and data on marine protected area (MPA) boundaries to analyze how ocean temperatures are affecting coral reef health at regional and global scales. I discovered that temperature anomalies are spatially and temporally variable from 1985-2005 even during El Nino events. They are also typically less than 50 km2, smaller than the resolution of many climate models. In addition, I found a strong relationship on the Great Barrier Reef between the number of temperature anomalies and the number of cases of white syndrome, a prevalent coral disease. Results from this study suggest that temperature anomalies are playing a major role in the observed decline of coral reefs over the last 30-40 years. This decline highlights the importance of determining whether MPAs, one of the most common management tools are effective in restoring coral cover. My analyses demonstrated that MPAs can confer some ecosystem resilience through fisheries management and land management practices at regional scales. Coral cover on reefs inside of MPAs did not change over time, while unprotected reefs experienced declines in coral cover. However, MPAs do not moderate the effect of thermal stress on corals or reduce coral decline at rates that can offset losses from thermal stress and other major natural and human-caused disturbances

  17. Pathfinder Aircraft in Flight

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long- duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar- powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus

  18. Use of integrated landscape indicators to evaluate the health of linked watersheds and coral reef environments in the Hawaiian islands.

    PubMed

    Rodgers, Ku'ulei S; Kido, Michael H; Jokiel, Paul L; Edmonds, Tim; Brown, Eric K

    2012-07-01

    A linkage between the condition of watersheds and adjacent nearshore coral reef communities is an assumed paradigm in the concept of integrated coastal management. However, quantitative evidence for this "catchment to sea" or "ridge to reef" relationship on oceanic islands is lacking and would benefit from the use of appropriate marine and terrestrial landscape indicators to quantify and evaluate ecological status on a large spatial scale. To address this need, our study compared the Hawai'i Watershed Health Index (HI-WHI) and Reef Health Index (HI-RHI) derived independently of each other over the past decade. Comparisons were made across 170 coral reef stations at 52 reef sites adjacent to 42 watersheds throughout the main Hawaiian Islands. A significant positive relationship was shown between the health of watersheds and that of adjacent reef environments when all sites and depths were considered. This relationship was strongest for sites facing in a southerly direction, but diminished for north facing coasts exposed to persistent high surf. High surf conditions along the north shore increase local wave driven currents and flush watershed-derived materials away from nearshore waters. Consequently, reefs in these locales are less vulnerable to the deposition of land derived sediments, nutrients and pollutants transported from watersheds to ocean. Use of integrated landscape health indices can be applied to improve regional-scale conservation and resource management. PMID:22538320

  19. Use of Integrated Landscape Indicators to Evaluate the Health of Linked Watersheds and Coral Reef Environments in the Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Rodgers, Ku`ulei S.; Kido, Michael H.; Jokiel, Paul L.; Edmonds, Tim; Brown, Eric K.

    2012-07-01

    A linkage between the condition of watersheds and adjacent nearshore coral reef communities is an assumed paradigm in the concept of integrated coastal management. However, quantitative evidence for this "catchment to sea" or "ridge to reef" relationship on oceanic islands is lacking and would benefit from the use of appropriate marine and terrestrial landscape indicators to quantify and evaluate ecological status on a large spatial scale. To address this need, our study compared the Hawai`i Watershed Health Index (HI-WHI) and Reef Health Index (HI-RHI) derived independently of each other over the past decade. Comparisons were made across 170 coral reef stations at 52 reef sites adjacent to 42 watersheds throughout the main Hawaiian Islands. A significant positive relationship was shown between the health of watersheds and that of adjacent reef environments when all sites and depths were considered. This relationship was strongest for sites facing in a southerly direction, but diminished for north facing coasts exposed to persistent high surf. High surf conditions along the north shore increase local wave driven currents and flush watershed-derived materials away from nearshore waters. Consequently, reefs in these locales are less vulnerable to the deposition of land derived sediments, nutrients and pollutants transported from watersheds to ocean. Use of integrated landscape health indices can be applied to improve regional-scale conservation and resource management.

  20. The LISA Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, L. I.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martín, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    LISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter. The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper

  1. JWST Pathfinder Telescope Integration

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI&T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  2. JWST pathfinder telescope integration

    NASA Astrophysics Data System (ADS)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-08-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI and T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  3. Pathfinder: A Retrospective

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Mars is one of the most interesting planets in the solar system, featuring enormous canyons, giant volcanoes, and indications that, early in its history, it might have had rivers and perhaps even oceans. Five years ago, in July of 1997, the Pathfinder mission landed on Mars, bringing with it the microwave-oven sized Sojourner rover to wander around on the surface and analyse rocks. Among the experiments on the mission was one designed to analyse dust deposition. Pathfinder is only the first of an armada of spacecraft which will examine Mars from the pole to the equator in the next decade, culminating with a mission to bring humans to Mars.

  4. Clues to Coral Reef Health: Integrating Radiative Transfer Modeling and Hyperspectral Data

    NASA Astrophysics Data System (ADS)

    Guild, L.; Ganapol, B.; Kramer, P.; Armstrong, R.; Gleason, A.; Torres, J.; Johnson, L.; Garfield, N.

    2002-12-01

    An important contribution to coral reef research is to improve spectral distinction between various health states of coral species in areas subject to harmful anthropogenic activity and climate change. New insights into radiative transfer properties of corals under healthy and stressed conditions can advance understandings of ecological processes on reefs and allow better assessments of the impacts of large-scale bleaching and disease events. Our objective is to examine the spectral and spatial properties of hyperspectral sensors that may be used to remotely sense changes in reef community health. We compare in situ reef environment spectra (healthy coral, stressed coral, dead coral, algae, and sand) with airborne hyperspectral data to identify important spectral characteristics and indices. Additionally, spectral measurements over a range of water depths, relief, and bottom types are compared to help quantify bottom-water column influences. In situ spectra was collected in July and August 2002 at the Long Rock site in the Andros Island, Bahamas coastal zone coral reef. Our primary emphasis is on Acropora palmata (or elkhorn coral), a major reef building coral, which is prevalent in the study area, but is suffering from white band disease. A. palmata is currently being proposed as an endangered species because its populations have severely declined in many areas of the Caribbean. In addition to the A. palmata biotope, we have collected spectra of at least seven other coral biotopes that exist within the study area, each with different coral community composition, density of corals, relief, and size of corals. Coral spectral reflectance is input into a radiative transfer model, CORALMOD (CM1), which is based on a leaf radiative transfer model. In CM1, input coral reflectance measurements produce modeled reflectance through an inversion at each visible wavelength to provide the absorption spectrum. Initially, we have imposed a scattering baseline that is the same

  5. Clues to Coral Reef Health: Integrating Radiative Transfer Modeling and Hyperspectral Data

    NASA Technical Reports Server (NTRS)

    Guild, Liane; Ganapol, Barry; Kramer, Philip; Armstrong, Roy; Gleason, Art; Torres, Juan; Johnson, Lee; Garfield, Toby; Peterson, David L. (Technical Monitor)

    2002-01-01

    An important contribution to coral reef research is to improve spectral distinction between various health states of coral species in areas subject to harmful anthropogenic activity and climate change. New insights into radiative transfer properties of corals under healthy and stressed conditions can advance understandings of ecological processes on reefs and allow better assessments of the impacts of large-scale bleaching and disease events, Our objective was to examine the spectral and spatial properties of hyperspectral sensors that may be used to remotely sense changes in reef community health. We compare in situ reef environment spectra (healthy coral, stressed coral, dead coral, algae, and sand) with airborne hyperspectral data to identify important spectral characteristics and indices. Additionally, spectral measurements over a range of water depths, relief, and bottom types are compared to help quantify bottom-water column influences. In situ spectra were collected in July and August 2002 at the Long Rock site in the Andros Island, Bahamas coastal zone coral reef. Our primary emphasis was on Acropora palmata (or elkhorn coral), a major reef building coral, which is prevalent in the study area, but is suffering from white band disease. A. palmata is currently being, proposed as an endangered species because its populations have severely declined in many areas of the Caribbean. In addition to the A. palmata biotope, we have collected spectra of at least seven other coral biotopes that exist within the study area, each with different coral community composition, density of corals, relief, and size of corals. Coral spectral reflectance was then input into a radiative transfer model, CORALMOD (CM1), which is based on a leaf radiative transfer model. In CM1, input coral reflectance measurements produce modeled reflectance through an inversion at each visible wavelength to provide the absorption spectrum. Initially, we imposed a scattering baseline that is the

  6. The LISA Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Thorpe, james; McNamara, P. W.

    2011-01-01

    LISA Pathfinder is a dedicated technology demonstration space mission for the Laser Interferometer Space Antenna (LISA), a NASA/ESA collaboration to operate a space-based observatory for gravitational waves in the milli-Hertz band. Although the formal partnership between the agencies was dissolved in the Spring of 2011, both agencies are actively pursuing concepts for LISA-like gravitational wave observatories. These concepts take advantage of the significant technology development efforts that have already been made, especially those of the LISA Pathfinder mission. LISA Pathfinder, which is in the late stages of implementation, will place two test masses in drag-free flight and measure the relative acceleration between them. This measurement will validate a number of technologies that are critical to LISA-like gravitational wave instruments including sensing and control of the test masses, drag-free control laws, microNewton thrusters, and picometer-level laser metrology. We will present the current status of the LISA Pathfinder mission and associated activities.

  7. Pathfinder Spies Dust Devils

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This set of images from NASA's 1997 Pathfinder mission highlight the dust devils that gust across the surface of Mars. The right image shows the dusty martian sky as our eye would see it. The left image has been enhanced to expose the dust devils that lurk in the hazy sky.

  8. The LISA Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Stebbins, Robin

    2009-01-01

    LISA Pathfinder (formerly known as SMART-2) is a European Space Agency (ESA) mission designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission by testing in flight the critical technologies required for spaceborne gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. LISA Pathfinder is currently in the integration and test phase of the development, and is due to be launched on a dedicated launch vehicle in late 2011, with first results on the performance of the system being available approx 6 months later. This poster will describe the mission in detail, give the current status of the spacecraft development, and highlight the future milestones in the integration and test campaign.

  9. VR for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Blackmon, Theodore

    1998-01-01

    Virtual reality (VR) technology has played an integral role for Mars Pathfinder mission, operations Using an automated machine vision algorithm, the 3d topography of the Martian surface was rapidly recovered fro -a the stereo images captured. by the Tender camera to produce photo-realistic 3d models, An advanced, interface was developed for visualization and interaction with. the virtual environment of the Pathfinder landing site for mission scientists at the Space Flight Operations Facility of the Jet Propulsion Laboratory. The VR aspect of the display allowed mission scientists to navigate on Mars in Bud while remaining here on Earth, thus improving their spatial awareness of the rock field that surrounds the lenders Measurements of positions, distances and angles could be easily extracted from the topographic models, providing valuable information for science analysis and mission. planning. Moreover, the VR map of Mars has also been used to assist with the archiving and planning of activities for the Sojourner rover.

  10. SKA and its pathfinders

    NASA Astrophysics Data System (ADS)

    Stappers, Ben

    2011-07-01

    The Square Kilometer Array will be the largest radio telescope in theworld, spreading out over an entire continent. It will revolutionize manyareas of astronomy and astrophysics. It is also an enormous engineeringchallenge. I will introduce some of the pathfinder instruments being builtaround the world and how they are leading to the SKA. I will also discuss some of the science that will be enabled by the SKA and highlight some of the specific engineering challenges.

  11. Mars Pathfinder [foldout].

    PubMed

    1997-12-01

    The following foldout present images and analysis from the Mars Pathfinder Mission that are discussed in seven subsequent Reports. The center is a four-page panorama of the surface of Mars around the lander (Plate 1). The back of the foldout contains surface images (Plate 7), a different perspective of the landing site (Plate 2), rover targets (Plate 3), locations of rocks and other features (Plate 6) and data analysis (Plates 4, 4, 8, 9, and 10). PMID:9411794

  12. Mars Pathfinder Status at Launch

    NASA Technical Reports Server (NTRS)

    Spear, A. J.; Freeman, Delma C., Jr.; Braun, Robert D.

    1996-01-01

    The Mars Pathfinder Flight System is in final test, assembly and launch preparations at the Kennedy Space Center in Florida. Launch is scheduled for 2 Dec. 1996. The Flight System development, in particular the Entry, Descent, and Landing (EDL) system, was a major team effort involving JPL, other NASA centers and industry. This paper provides a summary Mars Pathfinder description and status at launch. In addition, a section by NASA's Langley Research Center, a key EDL contributor, is provided on their support to Mars Pathfinder. This section is included as an example of the work performed by Pathfinder team members outside JPL.

  13. Reef grief

    NASA Astrophysics Data System (ADS)

    2011-10-01

    As the first of the world's ecosystems faces extermination at our hands, coral reef ecologist Peter Sale -- Assistant Director of the Institute of Water, Environment and Health at the United Nations University in Ontario, Canada, and author of Our Dying Planet (published this autumn) -- talks to Nature Climate Change.

  14. The Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Golombek, Matthew P.

    1997-01-01

    Mars Pathfinder, one of the first Discovery-class missions (quick, low-cost projects with focused science objectives), will land a single spacecraft with a microrover and several instruments on the surface of Mars in 1997. Pathfinder will be the first mission to use a rover, carrying a chemical analysis instrument, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which will provide a calibration point or "ground truth" for orbital remote sensing observations. In addition to the rover, which also performs a number of technology experiments, Pathfinder carries three science instruments: a stereoscopic imager with spectral filters on an extendable mast, an alpha proton X ray spectrometer, and an atmospheric structure instrument/meteorology package. The instruments, the rover technology experiments, and the telemetry system will allow investigations of the surface morphology and geology at submeter to a hundred meters scale, the petrology and geochemistry of rocks and soils, the magnetic properties of dust, soil mechanics and properties, a variety of atmospheric investigations, and the rotational and orbital dynamics of Mars. Landing downstream from the mouth of a giant catastrophic outflow channel, Ares Vallis at 19.5 deg N, 32.8 deg W, offers the potential of identifying and analyzing a wide variety of crustal materials, from the ancient heavily cratered terrain, intermediate-aged ridged plains, and reworked channel deposits, thus allowing first-order scientific investigations of the early differentiation and evolution of the crust, the development of weathering products, and tile early environments and conditions on Mars.

  15. Delta II Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Final preparations for lift off of the DELTA II Mars Pathfinder Rocket are shown. Activities include loading the liquid oxygen, completing the construction of the Rover, and placing the Rover into the Lander. After the countdown, important visual events include the launch of the Delta Rocket, burnout and separation of the three Solid Rocket Boosters, and the main engine cutoff. The cutoff of the main engine marks the beginning of the second stage engine. After the completion of the second stage, the third stage engine ignites and then cuts off. Once the third stage engine cuts off spacecraft separation occurs.

  16. National pathfinder survey on children's oral health in Italy: pattern and severity of caries disease in 4-year-olds.

    PubMed

    Campus, G; Solinas, G; Strohmenger, L; Cagetti, M G; Senna, A; Minelli, L; Majori, S; Montagna, M T; Reali, D; Castiglia, P

    2009-01-01

    This paper describes the dental health status of Italian 4-year-olds in 2004/2005 and analyzes the association between caries in preschool children and some background characteristics in children and parents. Caries was recorded according to WHO criteria. 5,538 subjects were examined. Information on the children's and their parents' social, behavioral, ethnic and demographic status was obtained through a series of closed questions. Bivariate analysis was performed to investigate the association between caries and background characteristics. The probability of being an extra zero for the dmfs index was estimated via the zero-inflated negative binomial regression model (ZINB). 78.4% (95% CI = 77.2-79.6) of the children were caries-free. The national mean dmfs index was 1.36 (95% CI = 1.15-1.57), ranging from 1.22 (95% CI = 1.03-1.42) in the Italian North-East to 1.73 (95% CI = 0.83-2.63) in the South section. Significant bivariate associations between caries experience and risk factors were observed for parents' nationality (not Italian vs. Italian: p < 0.001), parents' educational levels (low vs. high: p < 0.001), preterm birth (yes vs. no: p = 0.011), prolonged breastfeeding (13 months: p = 0.038) and early tooth eruption (<6 months as reference: p = 0.004). Multivariable analysis (ZINB) showed that children with a low caries risk level had a higher probability of being an extra zero; in particular, children from fathers with a high educational level showed a probability of being an extra zero of 0.22. The results suggest a need to plan preventive programs to reduce oral health disparities among Italian preschool children, based on educational intervention with parents and children concerning oral health and caries prevention. PMID:19365120

  17. Pathfinder Rover Atop Mermaid Dune

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mars Pathfinder Lander camera image of Sojourner Rover atop the Mermaid 'dune' on Sol 30. Note the dark material excavated by the rover wheels. These, and other excavations brought materials to the surface for examination and allowed estimates of mechanical properties of the deposits.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  18. LISA Pathfinder ground testing

    NASA Astrophysics Data System (ADS)

    Guzman, Felipe; LISA Pathfinder Team

    2010-01-01

    The space-based gravitational wave observatory LISA is a joint NASA-ESA mission that requires challenging technology to ensure pure geodetic trajectories of test masses and the interferometric measurement of distance variations between them. The LISA Pathfinder mission is an ESA-launched technology demonstrator of key LISA subsystems such as spacecraft control with micronewton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of pre-flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems is currently ongoing. Studies have been carried out on very sensitive torsion pendulums that effectively reproduce a free-fall condition for the test mass within a horizontal plane in the lab, down to frequencies < 0.1 mHz. Thermal gradient induced effects, impact of gas molecules, noisy charging, surface charge patches, and other effects have been investigated and their physical models consolidated. A final upper limit on non-modeled disturbances has also been obtained within one order of magnitude of LISA requirements at 1 mHz. The interferometry system has also been extensively studied to identify noise sources and develop approaches to mitigate them. Engineering models of the optical bench, laser head and laser modulators have been interconnected and tested for functionality and noise level in closed-loop operation, demonstrating the required optical metrology sensitivity to test mass displacement. This poster presents the current status in the development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts.

  19. Assessing community values for reducing agricultural emissions to improve water quality and protect coral health in the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Rolfe, John; Windle, Jill

    2011-12-01

    Policymakers wanting to increase protection of the Great Barrier Reef from pollutants generated by agriculture need to identify when measures to improve water quality generate benefits to society that outweigh the costs involved. The research reported in this paper makes a contribution in several ways. First, it uses the improved science understanding about the links between management changes and reef health to bring together the analysis of costs and benefits of marginal changes, helping to demonstrate the appropriate way of addressing policy questions relating to reef protection. Second, it uses the scientific relationships to frame a choice experiment to value the benefits of improved reef health, with the results of mixed logit (random parameter) models linking improvements explicitly to changes in "water quality units." Third, the research demonstrates how protection values are consistent across a broader population, with some limited evidence of distance effects. Fourth, the information on marginal costs and benefits that are reported provide policymakers with information to help improve management decisions. The results indicate that while there is potential for water quality improvements to generate net benefits, high cost water quality improvements are generally uneconomic. A major policy implication is that cost thresholds for key pollutants should be set to avoid more expensive water quality proposals being selected.

  20. Mapping and monitoring the health and vitality of coral reefs from satellite: a biospheric approach.

    PubMed

    Dustan, P; Chakrabarti, S; Alling, A

    2000-01-01

    Biospheric studies of coral reefs require a planetary perspective that only remote sensing from space can provide. This article reviews aspects of monitoring and mapping coral reefs using Landsat and Spot satellite images. It details design considerations for developing a sensor for equatorial orbiting spacecraft, including spectral characteristics of living corals and the spatial resolution required to map coral reef communities. Possible instrumentation choices include computer techniques, filtered imagers, push-broom spectral imagery, and a newly developed hyperspectral imaging scheme using tomographic reconstruction. We compare the salient features of each technique and describe concepts for a payload to conduct planetary-scale coral reef monitoring. PMID:11543553

  1. Development of ecotoxicology procedures for use in assessing health of coral reefs

    SciTech Connect

    Davies, P.S.; Marubini, F.

    1995-12-31

    There is widespread concern over the apparent worldwide decline in the health of coral reefs. However, assessment methods, other than long-term monitoring, have not yet been attempted. To remedy this the authors are developing ecotoxicology procedures to assess the effects of water quality factors on the corals themselves. Because of the problems of working with large, attached organisms, the authors have concentrated on developing small clonal preparations from corals with both a branching and a massive growth-form. For branching corals, tips (`nubbins`) are removed, and the cut surface ground smooth before cementing to 30mm x 30mm acrylic squares. Cores, or `explants`, 25mm in diameter are removed from massive corals and cemented into injection-moulded plastic cups, to protect the cut surfaces of the skeleton. Trays of up to 18 nubbins and explants may then be transferred to the reef, where they are affixed to previously installed concrete breeze blocks. They may then be retrieved as required to assess the effects of water quality upon them. For laboratory ecotoxicology experiments, the authors have devised a system of artificial lighting, using halide lamps, to grow coral nubbins and explants under controlled conditions. To test the effects of pollutants, the authors use measurements of respiration, photosynthesis and skeletal growth rate. Growth is measured by a very simple buoyant weighing procedure, which requires only an analytical laboratory balance, and an easily-constructed plastic box-shaped chamber. The method is sufficiently sensitive to measure growth over a 24 hour period in some fast-growing corals. The authors will describe the results of initial experiments, carried out at the Bellairs Research Institute, Barbados, on the effects of different levels of phosphate and nitrate in the seawater. For the first time, they are able to demonstrate the concentration-related decrease in growth rate associated with nitrate eutrophication.

  2. Launch Abort System Pathfinder Arrival

    NASA Video Gallery

    The Orion Launch Abort System, or LAS, pathfinder returned home to NASA Langley on Oct. 18 on its way to NASA's Kennedy Space Center. The hardware was built at Langley and was used in preparation f...

  3. LISA Pathfinder: mission and status

    NASA Astrophysics Data System (ADS)

    Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Boatella, C.; Bogenstahl, J.; Bortoluzzi, D.; Bosetti, P.; Caleno, M.; Cavalleri, A.; Cesa, M.; Chmeissani, M.; Ciani, G.; Conchillo, A.; Congedo, G.; Cristofolini, I.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Dunbar, N.; Fauste, J.; Ferraioli, L.; Fertin, D.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marin, A.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gilbert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guillaume, B.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hough, J.; Hoyland, D.; Hueller, M.; Huesler, J.; Jeannin, O.; Jennrich, O.; Jetzer, P.; Johlander, B.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mitchell, E.; Monsky, A.; Nicolini, D.; Nicolodi, D.; Nofrarias, M.; Pedersen, F.; Perreur-Lloyd, M.; Perreca, A.; Plagnol, E.; Prat, P.; Racca, G. D.; Rais, B.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Sanjuan, J.; Schleicher, A.; Schulte, M.; Shaul, D.; Stagnaro, L.; Strandmoe, S.; Steier, F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tombolato, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Weber, W. J.; Zweifel, P.

    2011-05-01

    LISA Pathfinder, the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology demonstrator for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission. The technologies required for LISA are many and extremely challenging. This coupled with the fact that some flight hardware cannot be fully tested on ground due to Earth-induced noise led to the implementation of the LISA Pathfinder mission to test the critical LISA technologies in a flight environment. LISA Pathfinder essentially mimics one arm of the LISA constellation by shrinking the 5 million kilometre armlength down to a few tens of centimetres, giving up the sensitivity to gravitational waves, but keeping the measurement technology: the distance between the two test masses is measured using a laser interferometric technique similar to one aspect of the LISA interferometry system. The scientific objective of the LISA Pathfinder mission consists then of the first in-flight test of low frequency gravitational wave detection metrology. LISA Pathfinder is due to be launched in 2013 on-board a dedicated small launch vehicle (VEGA). After a series of apogee raising manoeuvres using an expendable propulsion module, LISA Pathfinder will enter a transfer orbit towards the first Sun-Earth Lagrange point (L1). After separation from the propulsion module, the LPF spacecraft will be stabilized using the micro-Newton thrusters, entering a 500 000 km by 800 000 km Lissajous orbit around L1. Science results will be available approximately 2 months after launch.

  4. Coral Reef Health Indices versus the Biological, Ecological and Functional Diversity of Fish and Coral Assemblages in the Caribbean Sea.

    PubMed

    Díaz-Pérez, Leopoldo; Rodríguez-Zaragoza, Fabián Alejandro; Ortiz, Marco; Cupul-Magaña, Amílcar Leví; Carriquiry, Jose D; Ríos-Jara, Eduardo; Rodríguez-Troncoso, Alma Paola; García-Rivas, María Del Carmen

    2016-01-01

    This study evaluated the relationship between the indices known as the Reef Health Index (RHI) and two-dimensional Coral Health Index (2D-CHI) and different representative metrics of biological, ecological and functional diversity of fish and corals in 101 reef sites located across seven zones in the western Caribbean Sea. Species richness and average taxonomic distinctness were used to asses biological estimation; while ecological diversity was evaluated with the indices of Shannon diversity and Pielou´s evenness, as well as by taxonomic diversity and distinctness. Functional diversity considered the number of functional groups, the Shannon diversity and the functional Pielou´s evenness. According to the RHI, 57.15% of the zones were classified as presenting a "poor" health grade, while 42.85% were in "critical" grade. Based on the 2D-CHI, 28.5% of the zones were in "degraded" condition and 71.5% were "very degraded". Differences in fish and coral diversity among sites and zones were demonstrated using permutational ANOVAs. Differences between the two health indices (RHI and 2D-CHI) and some indices of biological, ecological and functional diversity of fish and corals were observed; however, only the RHI showed a correlation between the health grades and the species and functional group richness of fish at the scale of sites, and with the species and functional group richness and Shannon diversity of the fish assemblages at the scale of zones. None of the health indices were related to the metrics analyzed for the coral diversity. In general, our study suggests that the estimation of health indices should be complemented with classic community indices, or should at least include diversity indices of fish and corals, in order to improve the accuracy of the estimated health status of coral reefs in the western Caribbean Sea. PMID:27579575

  5. Hillary Clinton visits Pathfinder projects in Brazil.

    PubMed

    1996-01-01

    In October 1995, US First Lady Hillary Clinton visited a maternity hospital in Salvador, Brazil, in which a family planning (FP)/reproductive health program has been administered by Pathfinder International since 1981 with funding from USAID. During her tour of the facility, Clinton learned about the high degree of unmet need for FP in the region which results from a lack of sufficient resources to meet demand. Clinton, in turn, praised the state of Bahia for its emphasis on FP in low-income areas. PMID:12179683

  6. Mars Pathfinder Landing Site Workshop

    NASA Technical Reports Server (NTRS)

    Golombek, Matthew (Editor)

    1994-01-01

    The Mars Pathfinder Project is an approved Discovery-class mission that will place a lander and rover on the surface of the Red Planet in July 1997. The Mars Pathfinder Landing Site Workshop was designed to allow the Mars scientific community to provide input as to where to land Pathfinder on Mars. The workshop was attended by over 60 people from around the United States and from Europe. Over 20 landing sites were proposed at the workshop, and the scientific questions and problems concerning each were addressed. The workshop and the discussion that occured during and afterward have significantly improved the ability to select a scientifically exciting but safe landing site on Mars.

  7. The Sonic Pathfinder: An Evaluation.

    ERIC Educational Resources Information Center

    Dodds, Allan G.; And Others

    1984-01-01

    An objective evaluation of the Sonic Pathfinder, a new ultrasonic mobility aid, showed that use of the aid changes mobility in many ways. Reduced perception of environmental sounds was not reflected in performance. The majority of users traveled slowly and exhibited less than optimal strategies. (Author/CL)

  8. Pathfinder Teaching and Learning Units.

    ERIC Educational Resources Information Center

    Hawaii Univ., Honolulu. Sea Grant Program.

    This collection of teaching units were selected from materials developed during the Operation Pathfinder Institutes (OPI) which took place in the Pacific region between 1994 and 1999. The institutes were intended to provide upper elementary and middle school science teachers with an opportunity to develop a deeper understanding of the marine…

  9. Desert Pathfinder at Work

    NASA Astrophysics Data System (ADS)

    2005-09-01

    The Atacama Pathfinder Experiment (APEX) project celebrates the inauguration of its outstanding 12-m telescope, located on the 5100m high Chajnantor plateau in the Atacama Desert (Chile). The APEX telescope, designed to work at sub-millimetre wavelengths, in the 0.2 to 1.5 mm range, passed successfully its Science Verification phase in July, and since then is performing regular science observations. This new front-line facility provides access to the "Cold Universe" with unprecedented sensitivity and image quality. After months of careful efforts to set up the telescope to work at the best possible technical level, those involved in the project are looking with satisfaction at the fruit of their labour: APEX is not only fully operational, it has already provided important scientific results. "The superb sensitivity of our detectors together with the excellence of the site allow fantastic observations that would not be possible with any other telescope in the world," said Karl Menten, Director of the group for Millimeter and Sub-Millimeter Astronomy at the Max-Planck-Institute for Radio Astronomy (MPIfR) and Principal Investigator of the APEX project. ESO PR Photo 30/05 ESO PR Photo 30/05 Sub-Millimetre Image of a Stellar Cradle [Preview - JPEG: 400 x 627 pix - 200k] [Normal - JPEG: 800 x 1254 pix - 503k] [Full Res - JPEG: 1539 x 2413 pix - 1.3M] Caption: ESO PR Photo 30/05 is an image of the giant molecular cloud G327 taken with APEX. More than 5000 spectra were taken in the J=3-2 line of the carbon monoxide molecule (CO), one of the best tracers of molecular clouds, in which star formation takes place. The bright peak in the north of the cloud is an evolved star forming region, where the gas is heated by a cluster of new stars. The most interesting region in the image is totally inconspicuous in CO: the G327 hot core, as seen in methanol contours. It is a truly exceptional source, and is one of the richest sources of emission from complex organic molecules in the

  10. Spacetime Metrology with LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Congedo, Giuseppe

    2012-04-01

    LISA is the proposed ESA-NASA gravitational wave detector in the 0.1 mHz - 0.1 Hz band. LISA Pathfinder is the down-scaled version of a single LISA arm. The arm - named Doppler link - can be treated as a differential accelerometer, measuring the relative acceleration between test masses. LISA Pathfinder - the in-flight test of the LISA instrumentation - is currently in the final implementation and planned to be launched in 2014. It will set stringent constraints on the ability to put test masses in geodesic motion to within the required differential acceleration of 3times10^{-14} m s^{-2} Hz^{-1/2} and track their relative motion to within the required differential displacement measurement noise of 9times10^{-12} m Hz^{-1/2}, around 1 mHz. Given the scientific objectives, it will carry out - for the first time with such high accuracy required for gravitational wave detection - the science of spacetime metrology, in which the Doppler link between two free-falling test masses measures the curvature. This thesis contains a novel approach to the calculation of the Doppler response to gravitational waves. It shows that the parallel transport of 4-vectors records the history of gravitational wave signals. In practice, the Doppler link is implemented with 4 bodies in LISA and 3 bodies in LISA Pathfinder. To compensate for noise sources a control logic is implemented during the measurement. The closed-loop dynamics of LISA Pathfinder can be condensed into operators acting on the motion coordinates, handling the couplings, as well as the cross-talks. The scope of system identification is the optimal calibration of the instrument. This thesis describes some data analysis procedures applied to synthetic experiments and shows the relevance of system identification for the success of LISA Pathfinder in demonstrating the principles of spacetime metrology for all future space-based missions.

  11. LISA Pathfinder: A Mission Status

    NASA Astrophysics Data System (ADS)

    Hewitson, Martin; LISA Pathfinder Team Team

    2016-03-01

    On December 3rd at 04:04 UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space. This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.

  12. Multispectral Imaging from Mars PATHFINDER

    NASA Technical Reports Server (NTRS)

    Ferrand, William H.; Bell, James F., III; Johnson, Jeffrey R.; Bishop, Janice L.; Morris, Richard V.

    2007-01-01

    The Imager for Mars Pathfinder (IMP) was a mast-mounted instrument on the Mars Pathfinder lander which landed on Mars Ares Vallis floodplain on July 4, 1997. During the 83 sols of Mars Pathfinders landed operations, the IMP collected over 16,600 images. Multispectral images were collected using twelve narrowband filters at wavelengths between 400 and 1000 nm in the visible and near infrared (VNIR) range. The IMP provided VNIR spectra of the materials surrounding the lander including rocks, bright soils, dark soils, and atmospheric observations. During the primary mission, only a single primary rock spectral class, Gray Rock, was recognized; since then, Black Rock, has been identified. The Black Rock spectra have a stronger absorption at longer wavelengths than do Gray Rock spectra. A number of coated rocks have also been described, the Red and Maroon Rock classes, and perhaps indurated soils in the form of the Pink Rock class. A number of different soil types were also recognized with the primary ones being Bright Red Drift, Dark Soil, Brown Soil, and Disturbed Soil. Examination of spectral parameter plots indicated two trends which were interpreted as representing alteration products formed in at least two different environmental epochs of the Ares Vallis area. Subsequent analysis of the data and comparison with terrestrial analogs have supported the interpretation that the rock coatings provide evidence of earlier martian environments. However, the presence of relatively uncoated examples of the Gray and Black rock classes indicate that relatively unweathered materials can persist on the martian surface.

  13. Insights into the Coral Microbiome: Underpinning the Health and Resilience of Reef Ecosystems.

    PubMed

    Bourne, David G; Morrow, Kathleen M; Webster, Nicole S

    2016-09-01

    Corals are fundamental ecosystem engineers, creating large, intricate reefs that support diverse and abundant marine life. At the core of a healthy coral animal is a dynamic relationship with microorganisms, including a mutually beneficial symbiosis with photosynthetic dinoflagellates (Symbiodinium spp.) and enduring partnerships with an array of bacterial, archaeal, fungal, protistan, and viral associates, collectively termed the coral holobiont. The combined genomes of this coral holobiont form a coral hologenome, and genomic interactions within the hologenome ultimately define the coral phenotype. Here we integrate contemporary scientific knowledge regarding the ecological, host-specific, and environmental forces shaping the diversity, specificity, and distribution of microbial symbionts within the coral holobiont, explore physiological pathways that contribute to holobiont fitness, and describe potential mechanisms for holobiont homeostasis. Understanding the role of the microbiome in coral resilience, acclimation, and environmental adaptation is a new frontier in reef science that will require large-scale collaborative research efforts. PMID:27482741

  14. MARS PATHFINDER ENCAPSULATION IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    McDonnell Douglas workers in the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2) are installing a shipping container around the Mars Pathfinder spacecraft/PAM-D upper stage booster assembly in preparation for transferring the Pathfinder to Launch Complex (LC) 17 on Cape Canaveral Air Station. The Pathfinder will be encased in a protective fairing before being mated to the McDonnell Douglas Delta II expendable launch vehicle that will loft it into orbit. Mars Pathfinder is slated for liftoff Dec. 2 from LC 17B.

  15. Environmental Variability in the Florida Keys: Impacts on Coral Reef Resilience and Health

    NASA Astrophysics Data System (ADS)

    Soto, I. M.; Muller-Karger, F. E.

    2005-12-01

    Environmental variability contributes to both mass mortality and resilience in tropical coral reef communities. We assess variations in sea surface temperature (SST) and ocean color in the Florida Keys using satellite imagery, and provide insight into how this variability is associated with locations of resilient coral communities (those unaffected by or able to recover from major events). The project tests the hypothesis that areas with historically low environmental variability promote lower levels of coral reef resilience. Time series of SST from the Advanced Very High Resolution Radiometer (AVHRR) sensors and ocean color derived quantities (e.g., turbidity and chlorophyll) from the Sea-viewing Wide Field of View Sensor (SeaWiFS) are being constructed over the entire Florida Keys region for a period of twelve and nine years, respectively. These data will be compared with historical coral cover data derived from Landsat imagery (1984-2002). Improved understanding of the causes of coral reef decline or resilience will help protect and manage these natural treasures.

  16. Devonian reefs

    SciTech Connect

    Kuhme, A.K.

    1986-05-01

    Three reef settings in northern Alberta and British Columbia were examined: (1) shelf edge, in the Clarke Lake shale basin; (2) open-marine pinnacle, in the Clarke Lake shale basin; and (3) restricted basin pinnacle, in the Shekilie evaporite basin. The shelf-edge reef tends to be water prone and does not offer the same reserves potential as pinnacle reefs; therefore, it is not examined in detail. The pinnacle reefs in the open-marine setting tend to be gas prone, whereas the pinnacle reefs in the restricted basin setting tend to be oil prone. Seismic models were generated from geologic cross sections over existing, economically producing reef anomalies. Seismic responses from these models were then examined, and criteria for reef identification established. For the acid test, seismic anomalies that were tested by the drill bit were examined, and the validity of the reef identification criteria was confirmed. Examples include both economic successes and failures. A different set of criteria for pinnacle reef identification were established for open-marine and restricted basin settings. Criteria are not universally applicable, so each basin will have a different set. Detecting the content and amount of porosity in reefs using seismic studies is elusive at best and remains a challenge to the explorationist.

  17. Mars Pathfinder Atmosphere Entry Trajectory Design

    NASA Technical Reports Server (NTRS)

    Spencer, David A.

    1995-01-01

    The Mars Pathfinder spacecraft will enter the Martian atmosphere directly from the interplanetary trajectory, at a relatively high velocity. The design of the nominal entry trajectory, and the accurate determination of potential trajectory dispersions, is necessary for the development of the Pathfinder Entry, Descent, and Landing (EDL) System.

  18. Software Aids Visualization Of Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Weidner, Richard J.

    1996-01-01

    Report describes Simulator for Imager for Mars Pathfinder (SIMP) computer program. SIMP generates "virtual reality" display of view through video camera on Mars lander spacecraft of Mars Pathfinder mission, along with display of pertinent textual and graphical data, for use by scientific investigators in planning sequences of activities for mission.

  19. The Mars Pathfinder Science Data Processing System

    NASA Technical Reports Server (NTRS)

    Runkle, A. J.; Lorre, J. J.; Alexander, D. A.; LaVoie, S. K.; Woncik, P. J.; Duxbury, E. D.; McAuley, J. M.; Green, W. B.

    1998-01-01

    This paper will describe the system developed to support Mars Pathfinder, the technology that was used to provide sophisticated products at very low cost, and the variety of data products used to support Mars Pathfinder operations. This paper represents one phase of work performed at the Jet Propulsion Laboratory, California Instittue of Technology, under a contract with National Aeronautics and Space Administration.

  20. MARS PATHFINDER CAMERA TEST IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers from the Jet Propulsion Laboratory (JPL) are conducting a systems test of the imager for the Mars Pathfinder. Mounted on the Pathfinder lander, the imager (the white cylindrical element the worker is touching) is a specially designed camera featuring a stereo-imaging system with color capability provided by a set of selectable filters. It is mounted on an extendable mast that will pop up after the lander touches down on the Martian surface. The imager will transmit images of the terrain, allowing engineers back on Earth to survey the landing site before the Pathfinder rover is deployed to explore the area. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2. JPL manages the Pathfinder project for NASA.

  1. MARS PATHFINDER ENCAPSULATION IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder and mated PAM-D upper stage booster are ready for transfer from the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2) on KSC to Launch Complex 17 on Cape Canaveral Air Station. Uppermost is the Mars Pathfinder assembly, with its lander encased in a protective aeroshell attached to the circular cruise stage. Lowermost on the workstand is the PAM-D booster that will give the Pathfinder the final 'kick' to send it on its way to Mars. Once at Launch Complex (LC) 17, the Pathfinder will be encased in a protective fairing before being mated to the Delta II expendable launch vehicle that will loft it into orbit. Mars Pathfinder is slated for liftoff from LC 17B on Dec. 2.

  2. Metatranscriptome Sequencing of a Reef-building Coral Elucidates Holobiont Community Gene Functions in Health and Disease

    NASA Astrophysics Data System (ADS)

    Timberlake, S.; Helbig, T.; Fernando, S.; Penn, K.; Alm, E.; Thompson, F.; Thompson, J. R.

    2012-12-01

    The coral reefs of the Abrolhos Bank of Brazil play a vital ecological role in the health of the Southern Atlantic Ocean, but accelerating rates of disease, particularly white plague, threaten this ecosystem. Thus, an understanding of white plague disease and diagnostic tests for it are urgently needed. The coral animal is associated with a distinct microbiome, a diverse assemblage of eukaryotes, bacteria, and viruses. That these microbes have a great influence on the health of the coral has been long known, however, most of their functions are still mysterious. While recent studies have contrasted healthy and white-plague-associated communities, the causative agents and mechanisms of the disease remain unknown. We collected fragments of healthy and diseased corals, as well as post-disease skeleton, from 12 colonies of the genus Mussismilia, the major component of the reef structure in the Abrolhos bank, and increasingly, a victim of white-plague disease. Fragments were flash-frozen in situ, and prepped for culture-free high throughput sequencing of gene transcripts with the Illumina II-G. While the membership of the microbial communities associated with coral has been previously described, the a coral holobiont community's gene function has, to date, never been assayed by this powerful approach. We designed a bioinformatics pipeline to analyze the short-read data from this complex sample: identifying the functions of genes expressed in the holobiont, and describing the active community's taxonomic composition. We show that gene functions expressed by the coral's bacterial assemblage are distinct from those of the underlying skeleton, and we highlight differences in the disease samples. We find that gene markers for the dissimilatory sulfate reduction pathway more abundant in the disease state, and we further quantify this difference with qPCR. Finally, we report the abundant expression of highly repetitive transcripts in the diseased coral samples, and highlight

  3. Mars Pathfinder mission operations concepts

    NASA Technical Reports Server (NTRS)

    Sturms, Francis M., Jr.; Dias, William C.; Nakata, Albert Y.; Tai, Wallace S.

    1994-01-01

    The Mars Pathfinder Project plans a December 1996 launch of a single spacecraft. After jettisoning a cruise stage, an entry body containing a lander and microrover will directly enter the Mars atmosphere and parachute to a hard landing near the sub-solar latitude of 15 degrees North in July 1997. Primary surface operations last for 30 days. Cost estimates for Pathfinder ground systems development and operations are not only lower in absolute dollars, but also are a lower percentage of total project costs than in past planetary missions. Operations teams will be smaller and fewer than typical flight projects. Operations scenarios have been developed early in the project and are being used to guide operations implementation and flight system design. Recovery of key engineering data from entry, descent, and landing is a top mission priority. These data will be recorded for playback after landing. Real-time tracking of a modified carrier signal through this phase can provide important insight into the spacecraft performance during entry, descent, and landing in the event recorded data is never recovered. Surface scenarios are dominated by microrover activity and lander imaging during 7 hours of the Mars day from 0700 to 1400 local solar time. Efficient uplink and downlink processes have been designed to command the lander and microrover each Mars day.

  4. Low cost approach to Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Spear, Anthony J.

    1995-10-01

    Mars Pathfinder, launching in December '96 and landing in July '97, will demo a low cost delivery system to the surface of Mars. Historically, spacecraft that orbit or land on a distant body carry a large amount of fuel for braking. Mars Pathfinder, thrusting only for navigation, enters directly into the Martian atmosphere, aerobrakes with its aeroshell, deploys a parachute at 10 km above the surface and, within 100 m off the surface, ignites solid rockets for final braking prior to deployment of air bags which cushion touchdown. After landing, petals open to upright the lander, exposing solar panels to the sun. Even though the lander and rover are expected to last longer, the major objectives of Mars Pathfinder, demonstrating EDL (Entry, Descent, Landing) and lander-rover surface operations, will occur within the first few days, at which time panoramic images of the surface will be transmitted and the rover will be deployed to conduct both mobility tests and rock composition measurements. While Mars Pathfinder is primarily an engineering demo, it accomplishes a focused, exciting set of science investigations with a stereo, multi-color lander imager; atmospheric instrumentation, used as a weather station after landing; and the rover with cameras and the APXS (Alpha Proton X-ray Spectrometer). This paper features Mars Pathfinder's approach to innovative and cost effective mission accomplishment, under a development cost cap. Mars Pathfinder is pathfinding a new way of doing business at NASA and JPL for small, low cost, Discovery class missions.

  5. Mars pathfinder lander deployment mechanisms

    NASA Technical Reports Server (NTRS)

    Gillis-Smith, Greg R.

    1996-01-01

    The Mars Pathfinder Lander employs numerous mechanisms, as well as autonomous mechanical functions, during its Entry, Descent and Landing (EDL) Sequence. This is the first US lander of its kind, since it is unguided and airbag-protected for hard landing using airbags, instead of retro rockets, to soft land. The arrival condition, location, and orientation of the Lander will only be known by the computer on the Lander. The Lander will then autonomously perform the appropriate sequence to retract the airbags, right itself, and open, such that the Lander is nearly level with no airbag material covering the solar cells. This function uses two different types of mechanisms - the Airbag Retraction Actuators and the Lander Petal Actuators - which are designed for the high torque, low temperature, dirty environment and for limited life application. The development of these actuators involved investigating low temperature lubrication, Electrical Discharge Machining (EDM) to cut gears, and gear design for limited life use.

  6. The Pathfinder Chemical Transfer Propulsion Program

    NASA Technical Reports Server (NTRS)

    Hannum, Ned P.; Berkopec, Frank D.; Zurawski, Robert L.

    1989-01-01

    Pathfinder is a research and technology initiative by the National Aeronautics and Space Administration (NASA) intended to strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in FY-89. One of the four major thrusts is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which are expected to be operated and maintained in space. These advanced engines will enhance or enable a variety of future space exploration missions. The goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder are described.

  7. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  8. Navigation Flight Operations for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Vaughan, Robin M.; Kallemeyn, Pieter H., Jr.; Spencer, David A.; Braun, Robert D.

    2004-01-01

    On July 4, 1997, Mars Pathfinder became the first spacecraft to land on the surface of Mars in 21 years. Pathfinder was launched on December 4, 1996 and spent seven months en route to the red planet. This report discusses the navigation flight experience for the Mars Pathfinder interplanetary cruise. In particular, orbit determination and maneuver design and execution results are presented. Special emphasis is given to the navigation role in the days and hours leading up to and including the Entry, Descent, and Landing (EDL) phase.

  9. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). In the background is the Pathfinder cruise stage, which the lander will be mated to once its functional tests are complete. The lander will remain attached to this stage during its six-to-seven-month journey to Mars. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  10. Pathfinder-Plus flight in Hawaii

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Pathfinder-Plus flight in Hawaii June 2002 AeroVironment's Pathfinder-Plus solar-powered flying wing recently flew a three-flight demonstration of its ability to relay third-generation cell phone and video signals as well as provide Internet linkage. The two pods underneath the center section of the wing carried the advanced two-way telecom package, developed by Japanese telecommunications interests.

  11. Power and pyro subsystems for Mars Pathfinder

    SciTech Connect

    Shirbacheh, M.

    1997-12-31

    The Power and Pyro Subsystem (PPS) for Mars Pathfinder was designed to support the spacecraft activities during Launch, Cruise, Entry and Landing and Mars operation phases of the mission. The key design constraints were cost, volume and mass. The PPS consists of solar arrays, batteries and power electronics. This paper describes the Mars Pathfinder mission, key requirements on PPS, and PPS system architecture and description of each element of the PPS system.

  12. Re-evaluating the health of coral reef communities: baselines and evidence for human impacts across the central Pacific.

    PubMed

    Smith, Jennifer E; Brainard, Rusty; Carter, Amanda; Grillo, Saray; Edwards, Clinton; Harris, Jill; Lewis, Levi; Obura, David; Rohwer, Forest; Sala, Enric; Vroom, Peter S; Sandin, Stuart

    2016-01-13

    Numerous studies have documented declines in the abundance of reef-building corals over the last several decades and in some but not all cases, phase shifts to dominance by macroalgae have occurred. These assessments, however, often ignore the remainder of the benthos and thus provide limited information on the present-day structure and function of coral reef communities. Here, using an unprecedentedly large dataset collected within the last 10 years across 56 islands spanning five archipelagos in the central Pacific, we examine how benthic reef communities differ in the presence and absence of human populations. Using islands as replicates, we examine whether benthic community structure is associated with human habitation within and among archipelagos and across latitude. While there was no evidence for coral to macroalgal phase shifts across our dataset we did find that the majority of reefs on inhabited islands were dominated by fleshy non-reef-building organisms (turf algae, fleshy macroalgae and non-calcifying invertebrates). By contrast, benthic communities from uninhabited islands were more variable but in general supported more calcifiers and active reef builders (stony corals and crustose coralline algae). Our results suggest that cumulative human impacts across the central Pacific may be causing a reduction in the abundance of reef builders resulting in island scale phase shifts to dominance by fleshy organisms. PMID:26740615

  13. Which environmental factors predict seasonal variation in the coral health of Acropora digitifera and Acropora spicifera at Ningaloo Reef?

    PubMed

    Hinrichs, Saskia; Patten, Nicole L; Feng, Ming; Strickland, Daniel; Waite, Anya M

    2013-01-01

    The impact of physico-chemical factors on percent coral cover and coral health was examined on a spatial basis for two dominant Acropora species, A. digitifera and A. spicifera, at Ningaloo Reef (north-western Australia) in the southeast Indian Ocean. Coral health was investigated by measuring metabolic indices (RNA/DNA ratio and protein concentration), energy levels (lipid ratio) and autotrophic indices (chlorophyll a (chl a) and zooxanthellae density) at six stations during typical seasons (austral autumn 2010 (March and April), austral winter 2010 (August)) and during an extreme La Niña event in summer 2011 (February). These indices were correlated with 15 physico-chemical factors (measured immediately following coral sampling) to identify predictors for health indices. Variations in metabolic indices (protein concentration and RNA/DNA ratio) for A. spicifera were mainly explained by nitrogen, temperature and zooplankton concentrations under typical conditions, while for A. digitifera, light as well as phytoplankton, in particular picoeukaryotes, were important, possibly due to higher energy requirement for lipid synthesis and storage in A. digitifera. Optimum metabolic values occurred for both Acropora species at 26-28°C when autotrophic indices (chl a and zooxanthellae density) were lowest. The extreme temperature during the La Niña event resulted in a shift of feeding modes, with an increased importance of water column plankton concentrations for metabolic rates of A. digitifera and light and plankton for A. spicifera. Our results suggest that impacts of high sea surface temperatures during extreme events such as La Niña may be mitigated via reduction on metabolic rates in coral host. The high water column plankton concentrations and associated low light levels resulted in a shift towards high symbiont densities, with lower metabolic rates and energy levels than the seasonal norm for the coral host. PMID:23637770

  14. LISA Pathfinder Instrument Data Analysis

    NASA Technical Reports Server (NTRS)

    Guzman, Felipe

    2010-01-01

    LISA Pathfinder (LPF) is an ESA-launched demonstration mission of key technologies required for the joint NASA-ESA gravitational wave observatory in space, LISA. As part of the LPF interferometry investigations, analytic models of noise sources and corresponding noise subtraction techniques have been developed to correct for effects like the coupling of test mass jitter into displacement readout, and fluctuations of the laser frequency or optical pathlength difference. Ground testing of pre-flight hardware of the Optical Metrology subsystem is currently ongoing at the Albert Einstein Institute Hannover. In collaboration with NASA Goddard Space Flight Center, the LPF mission data analysis tool LTPDA is being used to analyze the data product of these tests. Furthermore, the noise subtraction techniques and in-flight experiment runs for noise characterization are being defined as part of the mission experiment master plan. We will present the data analysis outcome of preflight hardware ground tests and possible noise subtraction strategies for in-flight instrument operations.

  15. Mars Pathfinder Atmospheric Entry Navigation Operations

    NASA Technical Reports Server (NTRS)

    Braun, R. D.; Spencer, D. A.; Kallemeyn, P. H.; Vaughan, R. M.

    1997-01-01

    On July 4, 1997, after traveling close to 500 million km, the Pathfinder spacecraft successfully completed entry, descent, and landing, coming to rest on the surface of Mars just 27 km from its target point. In the present paper, the atmospheric entry and approach navigation activities required in support of this mission are discussed. In particular, the flight software parameter update and landing site prediction analyses performed by the Pathfinder operations navigation team are described. A suite of simulation tools developed during Pathfinder's design cycle, but extendible to Pathfinder operations, are also presented. Data regarding the accuracy of the primary parachute deployment algorithm is extracted from the Pathfinder flight data, demonstrating that this algorithm performed as predicted. The increased probability of mission success through the software parameter update process is discussed. This paper also demonstrates the importance of modeling atmospheric flight uncertainties in the estimation of an accurate landing site. With these atmospheric effects included, the final landed ellipse prediction differs from the post-flight determined landing site by less then 0.5 km in downtrack.

  16. The EUSO-Balloon pathfinder

    NASA Astrophysics Data System (ADS)

    Adams, J. H.; Ahmad, S.; Albert, J.-N.; Allard, D.; Anchordoqui, L.; Andreev, V.; Anzalone, A.; Arai, Y.; Asano, K.; Ave Pernas, M.; Baragatti, P.; Barrillon, P.; Batsch, T.; Bayer, J.; Bechini, R.; Belenguer, T.; Bellotti, R.; Belov, K.; Berlind, A. A.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Blaksley, C.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Blümer, J.; Bobik, P.; Bogomilov, M.; Bonamente, M.; Briggs, M. S.; Briz, S.; Bruno, A.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellinic, G.; Catalano, C.; Catalano, G.; Cellino, A.; Chikawa, M.; Christl, M. J.; Cline, D.; Connaughton, V.; Conti, L.; Cordero, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Dagoret-Campagne, S.; de Castro, A. J.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Dell'Oro, A.; De Simone, N.; Di Martino, M.; Distratis, G.; Dulucq, F.; Dupieux, M.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Falk, S.; Fang, K.; Fenu, F.; Fernández-Gómez, I.; Ferrarese, S.; Finco, D.; Flamini, M.; Fornaro, C.; Franceschi, A.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; Garipov, G.; Geary, J.; Gelmini, G.; Giraudo, G.; Gonchar, M.; González Alvarado, C.; Gorodetzky, P.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Higashide, K.; Ikeda, D.; Ikeda, H.; Inoue, N.; Inoue, S.; Insolia, A.; Isgrò, F.; Itow, Y.; Joven, E.; Judd, E. G.; Jung, A.; Kajino, F.; Kajino, T.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Karus, M.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Keilhauer, B.; Khrenov, B. A.; Kim, J.-S.; Kim, S.-W.; Kim, S.-W.; Kleifges, M.; Klimov, P. A.; Kolev, D.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; Lacombe, M.; Lachaud, C.; Lee, J.; Licandro, J.; Lim, H.; López, F.; Maccarone, M. C.; Mannheim, K.; Maravilla, D.; Marcelli, L.; Marini, A.; Martinez, O.; Masciantonio, G.; Mase, K.; Matev, R.; Medina-Tanco, G.; Mernik, T.; Miyamoto, H.; Miyazaki, Y.; Mizumoto, Y.; Modestino, G.; Monaco, A.; Monnier-Ragaigne, D.; Morales de los Ríos, J. A.; Moretto, C.; Morozenko, V. S.; Mot, B.; Murakami, T.; Murakami, M. Nagano; Nagata, M.; Nagataki, S.; Nakamura, T.; Napolitano, T.; Naumov, D.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Panasyuk, M. I.; Parizot, E.; Park, I. H.; Park, H. W.; Pastircak, B.; Patzak, T.; Paul, T.; Pennypacker, C.; Perez Cano, S.; Peter, T.; Picozza, P.; Pierog, T.; Piotrowski, L. W.; Piraino, S.; Plebaniak, Z.; Pollini, A.; Prat, P.; Prévôt, G.; Prieto, H.; Putis, M.; Reardon, P.; Reyes, M.; Ricci, M.; Rodríguez, I.; Rodríguez Frías, M. D.; Ronga, F.; Roth, M.; Rothkaehl, H.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez-Cano, G.; Sagawa, H.; Saito, A.; Sakaki, N.; Sakata, M.; Salazar, H.; Sánchez, S.; Santangelo, A.; Santiago Crúz, L.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, H.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Segreto, A.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shibata, T.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Siemieniec-Oziȩbło, G.; Silva López, H. H.; Sledd, J.; Słomińska, K.; Sobey, A.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, F.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Tenzer, C.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Trillaud, F.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tymieniecka, T.; Uchihori, Y.; Unger, M.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Valore, L.; Vankova, G.; Vigorito, C.; Villaseñor, L.; von Ballmoos, P.; Wada, S.; Watanabe, J.; Watanabe, S.; Watts, J.; Weber, M.; Weiler, T. J.; Wibig, T.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yamamoto, Y.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, K.; Yoshida, S.; Young, R.; Zotov, M. Yu.; Zuccaro Marchi, A.

    2015-11-01

    EUSO-Balloon is a pathfinder for JEM-EUSO, the Extreme Universe Space Observatory which is to be hosted on-board the International Space Station. As JEM-EUSO is designed to observe Ultra-High Energy Cosmic Rays (UHECR)-induced Extensive Air Showers (EAS) by detecting their ultraviolet light tracks "from above", EUSO-Balloon is a nadir-pointing UV telescope too. With its Fresnel Optics and Photo-Detector Module, the instrument monitors a 50 km2 ground surface area in a wavelength band of 290-430 nm, collecting series of images at a rate of 400,000 frames/sec. The objectives of the balloon demonstrator are threefold: a) perform a full end-to-end test of a JEM-EUSO prototype consisting of all the main subsystems of the space experiment, b) measure the effective terrestrial UV background, with a spatial and temporal resolution relevant for JEM-EUSO. c) detect tracks of ultraviolet light from near space for the first time. The latter is a milestone in the development of UHECR science, paving the way for any future space-based UHECR observatory. On August 25, 2014, EUSO-Balloon was launched from Timmins Stratospheric Balloon Base (Ontario, Canada) by the balloon division of the French Space Agency CNES. From a float altitude of 38 km, the instrument operated during the entire astronomical night, observing UV-light from a variety of ground-covers and from hundreds of simulated EASs, produced by flashers and a laser during a two-hour helicopter under-flight.

  17. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a electrical test of its pyrotechnic system by Jet Propulsion Laboratory (JPL) engineers Lorraine Garcia (foreground) and Linda Robeck in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). A wheel of the Sojourner autonomous rover, which is attached to one of the lander's petals, can be seen behind the lander. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  18. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a test of its pyrotechnic system by Jet Propulsion Laboratory (JPL) engineer Jerry Gutierrez in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). A wheel of the Sojourner autonomous rover, which is attached to one of the lander's petals, can be seen behind the lander. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  19. Overhead view of Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image, prepared by Pathfinder scientists at NASA/ Ames Research Center, is a view of the landing site from above. Seen in the lower right is Mermaid dune, with its long axis oriented northwest-southeast and its steeper side, the presumed slipface, toward the southwest. Dunes like Mermaid, the depositional tails and erosional moats associated with rocks in the area, and the fluted and polished surfaces on several boulders at the landing site all indicate an effective wind that blows from the northeast to the southwest.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  20. Dynamic Pathfinders: Leveraging Your OPAC to Create Resource Guides

    ERIC Educational Resources Information Center

    Hunter, Ben

    2008-01-01

    Library pathfinders are a time-tested method of leading library users to important resources. However, paper-based pathfinders suffer from space limitations, and both paper-based and Web-based pathfinders require frequent updates to keep up with new library acquisitions. This article details a step-by-step method to create an online dynamic…

  1. Using MODIS data for understanding changes in seagrass meadow health: a case study in the Great Barrier Reef (Australia).

    PubMed

    Petus, Caroline; Collier, Catherine; Devlin, Michelle; Rasheed, Michael; McKenna, Skye

    2014-07-01

    Stretching more than 2000 km along the Queensland coast, the Great Barrier Reef Marine Park (GBR) shelters over 43,000 square km of seagrass meadows. Despite the status of marine protected area and World Heritage listing of the GBR, local seagrass meadows are under stress from reduced water quality levels; with reduction in the amount of light available for seagrass photosynthesis defined as the primary cause of seagrass loss throughout the GBR. Methods have been developed to map GBR plume water types by using MODIS quasi-true colour (hereafter true colour) images reclassified in function of their dominant colour. These data can be used as an interpretative tool for understanding changes in seagrass meadow health (as defined in this study by the seagrass area and abundance) at different spatial and temporal scales. We tested this method in Cleveland Bay, in the northern GBR, where substantial loss in seagrass area and biomass was detected by annual monitoring from 2007 to 2011. A strong correlation was found between bay-wide seagrass meadow area and biomass and exposure to turbid Primary (sediment-dominated) water type. There was also a strong correlation between the changes of biomass and area of individual meadows and exposure of seagrass ecosystems to Primary water type over the 5-year period. Seagrass meadows were also grouped according to the dominant species within each meadow, irrespective of location within Cleveland Bay. These consolidated community types did not correlate well with the exposure to Primary water type, and this is likely to be due to local environmental conditions with the individual meadows that comprise these groupings. This study proved that remote sensing data provide the synoptic window and repetitivity required to investigate changes in water quality conditions over time. Remote sensing data provide an opportunity to investigate the risk of marine-coastal ecosystems to light limitation due to increased water turbidity when in situ

  2. Pathfinder Landing Site in Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 14 May 2004 This image of the Mars Pathfinder Landing site was acquired July 17, 2002, during northern spring.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude 19.4, Longitude 326.8 East (33.2 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science

  3. System modelling for LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Diaz-Aguiló, Marc; Grynagier, Adrien; Rais, Boutheina

    LISA Pathfinder is the technology demonstrator for LISA, a space-borne gravitational waves observatory. The goal of the mission is to characterise the dynamics of the LISA Technology Package (LTP) to prove that on-board experimental conditions are compatible with the de-tection of gravitational waves. The LTP is a drag-free dynamics experiment which includes a control loop with sensors (interferometric and capacitive), actuators (capacitive actuators and thrusters), controlled disturbances (magnetic coils, heaters) and which is subject to various endogenous or exogenous noise sources such as infrared pressure or solar wind. The LTP experiment features new hardware which was never flown in space. The mission has a tight operation timeline as it is constrained to about 100 days. It is therefore vital to have efficient and precise means of investigation and diagnostics to be used during the on-orbit operations. These will be conducted using the LTP Data Analysis toolbox (LTPDA) which allows for simulation, parameter identification and various analyses (covariance analysis, state estimation) given an experimental model. The LTPDA toolbox therefore contains a series of models which are state-space representations of each component in the LTP. The State-Space Models (SSM) are objects of a state-space class within the LTPDA toolbox especially designed to address all the requirements of this tool. The user has access to a set of linear models which represent every satellite subsystem; the models are available in different forms representing 1D, 2D and 3D systems, each with settable symbolic and numeric parameters. To limit the possible errors, the models can be automatically linked to produce composite systems and closed-loops of the LTP. Finally, for the sake of completeness, accuracy and maintainability of the tool, the models contain all the physical information they mimic (i.e. variable units, description of parameters, description of inputs/outputs, etc). Models

  4. Mars Pathfinder Landing Site and Surroundings

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Pathfinder landed on Mars on July 4, 1997, and continued operating until Sept. 27 of that year. The landing site is on an ancient flood plain of the Ares and Tiu outflow channels. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took an image on Dec. 21, 2006, that provides unprecedented detail of the geology of the region and hardware on the surface.

    [figure removed for brevity, see original site] HiRISE Image This is the entire image. The crater at center bottom was unofficially named 'Big Crater' by the Pathfinder team. Its wall was visible from Pathfinder, located 3 kilometers (2 miles) to the north. The two bright features to the upper left of Big Crater are the 'Twin Peaks,' also observed by Pathfinder. The bright mound to the upper right of the Twin Peaks is 'North Knob,' seen in Pathfinder images as peaking over the horizon.

    At this scale there is no obvious geologic evidence of an ancient flood. Rather, impact craters dominate the scene, attesting to an old surface. The age is probably on the order of 1.8 billion to 3.5 billion years, when the Ares and Tiu floods are estimated to have occurred. Wind-formed linear ripples and dunes are seen throughout and are concentrated within craters. Sets of polygonal ridges of enigmatic origin are seen east of the Pathfinder lander. Rocks are visible over the entire image, with heavy concentrations near fresh-looking craters. Most of them are probably blocks tossed outward by crater-forming impacts.

    The complete image is centered at 19.1 degrees north latitude, 326.8 degrees east longitude. The range to the target site was 284.7 kilometers (177.9 miles). At this distance the image scale is 28.5 centimeters (11 inches) per pixel, so objects about 85 centimeters (33 inches) across are resolved. The image shown here has been map-projected to 25 centimeters (10 inches) per pixel. North is up. The image was taken at a local Mars time

  5. NASA's Chemical Transfer Propulsion Program for Pathfinder

    NASA Technical Reports Server (NTRS)

    Hannum, Ned P.; Berkopec, Frank D.; Zurawski, Robert L.

    1989-01-01

    Pathfinder is a research and technology project, with specific deliverables, initiated by the National Aeronautics and Space Administration (NASA) which will strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in Fiscal Year 1989, and is to advance a collection of critical technologies for these missions and ensure technology readiness for future national decisions regarding exploration of the solar system. The four major thrusts of Pathfinder are: surface exploration, in-space operations, humans-in-space, and space transfer. The space transfer thrust will provide the critical technologies needed for transportation to, and return from, the Moon, Mars, and other planets in the solar system, as well as for reliable and cost-effective Earth-orbit operations. A key element of this thrust is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which may be operated and maintained in space. Described here are the program overview including the goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder.

  6. Mechanical design of the Mars Pathfinder mission

    NASA Technical Reports Server (NTRS)

    Eisen, Howard Jay; Buck, Carl W.; Gillis-Smith, Greg R.; Umland, Jeffrey W.

    1997-01-01

    The Mars Pathfinder mission and the Sojourner rover is reported on, with emphasis on the various mission steps and the performance of the technologies involved. The mechanical design of mission hardware was critical to the success of the entry sequence and the landing operations. The various mechanisms employed are considered.

  7. Pathfinders on Black Dance in America.

    ERIC Educational Resources Information Center

    Roy, Loriene, Ed.

    This is a compilation of 18 pathfinders (i.e., a bibliographic instruction aid) on black dance in America, prepared by graduate students in the "Information Resources in the Humanities" and the "Information Resources in the Social Sciences" classes in the Graduate School of Library and Information Science at the University of Texas at Austin. The…

  8. Regenerative fuel cell systems for project pathfinder

    NASA Technical Reports Server (NTRS)

    Huff, J. R.; Hedstrom, J.; Vanderborgh, N. E.; Prokopius, P.

    1989-01-01

    The objectives of a surface power program, an element of the exploration thrust of the Pathfinder project, and plans for meeting them are outlined. Technological assessment and tradeoff studies of fuel cell and electrolyzer technologies suitable for use in a regenerative fuel cell are described. The viability of proton exchange membranes (PEM) in meeting the system requirements is discussed.

  9. Strategy for selecting Mars Pathfinder landing sites

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Kuzmin, Ruslin O.

    1994-01-01

    A strategy for Pathfinder site selection must be developed that is fundamentally different from most previous considerations. At least two approaches can be identified. In one approach, the objective is to select a site representing a key geologic unit on Mars, i.e., a unit that is widespread, easily recognized, and used frequently as a datum in various investigations. The second approach is to select a site that potentially affords access to a wide variety of rock types. Because rover range is limited, rocks from a variety of sources must be assembled in a small area for sampling. Regardless of the approach taken in site selection, the Pathfinder site should include eolian deposits and provisions should be made to obtain measurements on soils. A recommended approach for selecting the Mars Pathfinder landing site is to identify a deltaic deposit, composed of sediments derived from sources of various ages and geologic units that shows evidence of eolian activity. The site should be located as close as possible to the part of the outwash where rapid deposition occurred because the likelihood of 'sorting' by size and composition increases with distance, decreasing the probability of heterogeneity. In addition, it is recommended that field operation tests be conducted to gain experience and insight into conducting science with Pathfinder.

  10. Free-Flight Experiments in LISA Pathfinder

    NASA Technical Reports Server (NTRS)

    Thorpe, J. I.; Cutler, C. J.; Hewitson, M.; Jennrich, O.; Maghami, P.; Paczkowski, S.; Russano, G.; Vitale, S.; Weber, W. J.

    2014-01-01

    The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this 'suspension noise'. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.

  11. Pathfinders: An Intellectual Guide to Libraries.

    ERIC Educational Resources Information Center

    Jung, Claudia Ruediger; And Others

    Intended as an example for other college libraries, this collection of 38 pathfinders and bibliographies was developed by the reference staff of the Calvin Coolidge Library at Castleton State College, Vermont. Designed to present the types of literature available in particular subject fields and those works readily available in the Coolidge…

  12. Mars Pathfinder mechanically pumped cooling loop

    NASA Technical Reports Server (NTRS)

    Birur, G. C.

    2001-01-01

    A mechanically pumped single-phase cooling loop was successfully flown on the Mars Pathfinder (MPF) Spacecraft which safely landed on the Martian surface on July 4, 1997. One of the key technologies that enabled the mission to succeed was an active heat rejection system (HRS) used to cool the electronics on the spacecraft during its seven-month cruise from Earth to Mars.

  13. Mars Pathfinder Project: Planetary Constants and Models

    NASA Technical Reports Server (NTRS)

    Lyons, D.; Vaughn, R.

    1999-01-01

    This document provides a common set of astrodynamic constants and planetary models for use by the Mars pathfinder Project. It attempts to collect in a single reference all the quantities and models in use across the project during development and for mission operations.

  14. The Magnetic Properties Experiments on Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Knudsen, J. M.; Gunnlaugsson, H. P.; Hviid, S. F.; Madsen, M. B.

    1996-09-01

    A remarkable result from the Viking missions was the discovery that the Martian soil is highly magnetic, in the sense that the soil is attracted by permanent magnets. Both the strong and weak magnets on the Viking landers were saturated with dust throughout the mission. Appropriate limits for the spontaneous magnetization sigma_S were advanced: 1 Am(2) (kg soil)(-1) < sigma_S < 7 Am(2) (kg soil)(-1) . The essential difference between the Magnet Arrays for Mars Pathfinder and the Viking Magnetic Properties Experiment is that Magnet Arrays on Pathfinder will include magnets of lower strengths that the weakest Viking magnet. The five magnets consist of small ring magnets concentric with oppositely polarized cylindrical magnets. The outer diameter of the ring magnets is 18 mm. Discrete (single phase) particles of strongly magnetic minerals (gamma -Fe2O3 or Fe3O4) will stick to all five magnets, while composite (multiphase) particles will stick preferentially to the strongest magnets. Two Magnet Arrays are placed on the Pathfinder lander, with a distance of 1180 and 1450 mm, respectively, from the Imager for Mars Pathfinder (IMP). The magnets will attract airborne dust, and the dust on the magnets will be periodically viewed by the IMP. The images transmitted to Earth are the data on which conclusions on the magnetic properties of the dust will be based. Besides the Magnet Arrays the Pathfinder lander carries two other types of magnets. The Tip Plate Magnet is placed at a distance of 10 cm from the IMP, and thus allows a rather high resolution imaging of the dust clinging to the magnet. The Ramp Magnets are placed near the end of the ramps by which the micro-rover will descend to the surface. The dust on the Ramp Magnets will be studied by the APX-spectrometer of the micro-rover.

  15. A Paddock to reef monitoring and modelling framework for the Great Barrier Reef: Paddock and catchment component.

    PubMed

    Carroll, Chris; Waters, David; Vardy, Suzanne; Silburn, David M; Attard, Steve; Thorburn, Peter J; Davis, Aaron M; Halpin, Neil; Schmidt, Michael; Wilson, Bruce; Clark, Andrew

    2012-01-01

    Targets for improvements in water quality entering the Great Barrier Reef (GBR) have been set through the Reef Water Quality Protection Plan (Reef Plan). To measure and report on progress towards the targets set a program has been established that combines monitoring and modelling at paddock through to catchment and reef scales; the Paddock to Reef Integrated Monitoring, Modelling and Reporting Program (Paddock to Reef Program). This program aims to provide evidence of links between land management activities, water quality and reef health. Five lines of evidence are used: the effectiveness of management practices to improve water quality; the prevalence of management practice adoption and change in catchment indicators; long-term monitoring of catchment water quality; paddock & catchment modelling to provide a relative assessment of progress towards meeting targets; and finally marine monitoring of GBR water quality and reef ecosystem health. This paper outlines the first four lines of evidence. PMID:22277580

  16. The Global Coral Reef Crisis: Trends and Solutions (Coral Reefs: Values, Threats, and the Marine Aquarium Trade)

    SciTech Connect

    Shuman, Craig S.

    2003-02-05

    Second only to tropical rainforests, coral reefs support one of the world's most diverse natural habitats. Over 350 million individuals depend on coral reef resources for food and income. Unfortunately, the Earth is in the midst of a coral reef crisis. Anthropogenic impacts including overfishing, destructive fishing practices, sedimentation and pollution, as well as global climate change, have served to disrupt the natural processes that maintain the health of these ecosystems. Until recently, however, the global extent of the coral reef crisis was unknown. Reef Check was developed in 1996 as a volunteer, community-based monitoring protocol designed to measure the health of coral reefs on a global scale. With goals of education, monitoring, and management, Reef Check has activities in over 60 countries and territories. They have not only provided scientific evidence of the global extent of the coral reef crisis, but have provided the first community based steps to alleviate this urgent situation.

  17. Coral reef bleaching: ecological perspectives

    NASA Astrophysics Data System (ADS)

    Glynn, P. W.

    1993-03-01

    Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt

  18. Assessment of Mars Pathfinder landing site predictions

    USGS Publications Warehouse

    Golombek, M.P.; Moore, H.J.; Haldemann, A.F.C.; Parker, T.J.; Schofield, J.T.

    1999-01-01

    Remote sensing data at scales of kilometers and an Earth analog were used to accurately predict the characteristics of the Mars Pathfinder landing site at a scale of meters. The surface surrounding the Mars Pathfinder lander in Ares Vallis appears consistent with orbital interpretations, namely, that it would be a rocky plain composed of materials deposited by catastrophic floods. The surface and observed maximum clast size appears similar to predictions based on an analogous surface of the Ephrata Fan in the Channeled Scabland of Washington state. The elevation of the site measured by relatively small footprint delay-Doppler radar is within 100 m of that determined by two-way ranging and Doppler tracking of the spacecraft. The nearly equal elevations of the Mars Pathfinder and Viking Lander 1 sites allowed a prediction of the atmospheric conditions with altitude (pressure, temperature, and winds) that were well within the entry, descent, and landing design margins. High-resolution (~38 m/pixel) Viking Orbiter 1 images showed a sparsely cratered surface with small knobs with relatively low slopes, consistent with observations of these features from the lander. Measured rock abundance is within 10% of that expected from Viking orbiter thermal observations and models. The fractional area covered by large, potentially hazardous rocks observed is similar to that estimated from model rock distributions based on data from the Viking landing sites, Earth analog sites, and total rock abundance. The bulk and fine-component thermal inertias measured from orbit are similar to those calculated from the observed rock size-frequency distribution. A simple radar echo model based on the reflectivity of the soil (estimated from its bulk density), and the measured fraction of area covered by rocks was used to approximate the quasi-specular and diffuse components of the Earth-based radar echos. Color and albedo orbiter data were used to predict the relatively dust free or unweathered

  19. Project O.R.B (Operation Reef Ball): Creating Artificial Reefs, Educating the Community

    NASA Astrophysics Data System (ADS)

    Phipps, A.

    2012-04-01

    The Project O.R.B. (Operation Reef Ball) team at South Plantation High School's Everglades Restoration & Environmental Science Magnet Program is trying to help our ailing south Florida coral reefs by constructing, deploying, and monitoring designed artificial reefs. Students partnered with the Reef Ball Foundation, local concrete companies, state parks, Girl Scouts, Sea Scouts, local universities and environmental agencies to construct concrete reef balls, each weighing approximately 500 lbs (227 kg). Students then deployed two artificial reefs consisting of over 30 concrete reef balls in two sites previously permitted for artificial reef deployment. One artificial reef was placed approximately 1.5 miles (2.4 km) offshore of Golden Beach in Miami-Dade County with the assistance of Florida Atlantic University and their research vessel. A twin reef was deployed at the mouth of the river in Oleta River State Park in Miami. Monitoring and maintenance of the sites is ongoing with semi-annual reports due to the Reef Ball Foundation and DERM (Department of Environmental Resource Management) of Miami-Dade County. A second goal of Project O.R.B. is aligned with the Florida Local Action Strategy, the Southeast Florida Coral Reef Initiative, and the U.S. Coral Reef Task Force, all of which point out the importance of awareness and education as key components to the health of our coral reefs. Project O.R.B. team members developed and published an activity book targeting elementary school students. Outreach events incorporate cascade learning where high school students teach elementary and middle school students about various aspects of coral reefs through interactive "edu-tainment" modules. Attendees learn about water sampling, salinity, beach erosion, surface runoff, water cycle, ocean zones, anatomy of coral, human impact on corals, and characteristics of a well-designed artificial reef. Middle school students snorkel on the artificial reef to witness first-hand the success

  20. Potential landing sites for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Kuzmin, Ruslan O.; Landheim, R.; Greeley, Ronald

    1994-01-01

    In addition to a better understanding of the geological evolution of Mars, new techniques for processing available data have emerged, new data have been acquired, and the engineering approaches for placing spacecraft on the surface have evolved. Selection of the Mars Pathfinder landing site must take these issues into account, along with mission constraints. An advantage of Mars Pathfinder is the rover for sampling surface materials over a range of tens of meters. However, engineering constraints and the limited scientific payload of this mission require new approaches for landing site selection. One approach is to select sites exhibiting a wide variety of rocks near the lander. An alternative approach is to select sites in which the regional geology consists of a single rock type representing a key datum for the geological study of Mars, and is uniformly distributed within the landing ellipse.

  1. Mapping Oyster Reef Habitats in Mobile Bay

    NASA Technical Reports Server (NTRS)

    Bolte, Danielle

    2011-01-01

    Oyster reefs around the world are declining rapidly, and although they haven t received as much attention as coral reefs, they are just as important to their local ecosystems and economies. Oyster reefs provide habitats for many species of fish, invertebrates, and crustaceans, as well as the next generations of oysters. Oysters are also harvested from many of these reefs and are an important segment of many local economies, including that of Mobile Bay, where oysters rank in the top five commercial marine species both by landed weight and by dollar value. Although the remaining Mobile Bay oyster reefs are some of the least degraded in the world, projected climate change could have dramatic effects on the health of these important ecosystems. The viability of oyster reefs depends on water depth and temperature, appropriate pH and salinity levels, and the amount of dissolved oxygen in the water. Projected increases in sea level, changes in precipitation and runoff patterns, and changes in pH resulting from increases in the amount of carbon dioxide dissolved in the oceans could all affect the viability of oyster reefs in the future. Human activities such as dredging and unsustainable harvesting practices are also adversely impacting the oyster reefs. Fortunately, several projects are already under way to help rebuild or support existing or previously existing oyster reefs. The success of these projects will depend on the local effects of climate change on the current and potential habitats and man s ability to recognize and halt unsustainable harvesting practices. As the extent and health of the reefs changes, it will have impacts on the Mobile Bay ecosystem and economy, changing the resources available to the people who live there and to the rest of the country, since Mobile Bay is an important national source of seafood. This project identified potential climate change impacts on the oyster reefs of Mobile Bay, including the possible addition of newly viable

  2. Mars Pathfinder Project: Planetary Constants and Models

    NASA Technical Reports Server (NTRS)

    Vaughan, Robin

    1995-01-01

    This document provides a common set of astrodynamic constants and planetary models for use by the Mars Pathfinder Project. It attempts to collect in a single reference all the quantities and models in use across the project during development and for mission operations. These models are central to the navigation and mission design functions, but they are also used in other aspects of the project such as science observation planning and data reduction.

  3. Stress analysis of Pathfinder-2 models

    NASA Technical Reports Server (NTRS)

    Mehrotra, S. C.; Mills, C. T. L.

    1984-01-01

    Stress analysis of the Pathfinder 2 fighter model was performed to determine a method for leading- and trailing-edge attachment that gives acceptable stress levels. Structural modeling of the wing was done using the finite element code SPAR. For the models studied, one ordinary lap joint was found to be satisfactory for the leading-edge flap, however, the alternating surface segmented lap joint method fo attachment was necessary for the trailing-edge flap to obtain acceptable stress levels.

  4. Canadian Hydrogen Intensity Mapping Experiment (CHIME) pathfinder

    NASA Astrophysics Data System (ADS)

    Bandura, Kevin; Addison, Graeme E.; Amiri, Mandana; Bond, J. Richard; Campbell-Wilson, Duncan; Connor, Liam; Cliche, Jean-François; Davis, Greg; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; Gibbs, Kenneth; Gilbert, Adam; Halpern, Mark; Hanna, David; Hincks, Adam D.; Hinshaw, Gary; Höfer, Carolin; Klages, Peter; Landecker, Tom L.; Masui, Kiyoshi; Mena Parra, Juan; Newburgh, Laura B.; Pen, Ue-li; Peterson, Jeffrey B.; Recnik, Andre; Shaw, J. Richard; Sigurdson, Kris; Sitwell, Mike; Smecher, Graeme; Smegal, Rick; Vanderlinde, Keith; Wiebe, Don

    2014-07-01

    A pathfinder version of CHIME (the Canadian Hydrogen Intensity Mapping Experiment) is currently being commissioned at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. The instrument is a hybrid cylindrical interferometer designed to measure the large scale neutral hydrogen power spectrum across the redshift range 0.8 to 2.5. The power spectrum will be used to measure the baryon acoustic oscillation (BAO) scale across this poorly probed redshift range where dark energy becomes a significant contributor to the evolution of the Universe. The instrument revives the cylinder design in radio astronomy with a wide field survey as a primary goal. Modern low-noise amplifiers and digital processing remove the necessity for the analog beam forming that characterized previous designs. The Pathfinder consists of two cylinders 37m long by 20m wide oriented north-south for a total collecting area of 1,500 square meters. The cylinders are stationary with no moving parts, and form a transit instrument with an instantaneous field of view of ~100 degrees by 1-2 degrees. Each CHIME Pathfinder cylinder has a feedline with 64 dual polarization feeds placed every ~30 cm which Nyquist sample the north-south sky over much of the frequency band. The signals from each dual-polarization feed are independently amplified, filtered to 400-800 MHz, and directly sampled at 800 MSps using 8 bits. The correlator is an FX design, where the Fourier transform channelization is performed in FPGAs, which are interfaced to a set of GPUs that compute the correlation matrix. The CHIME Pathfinder is a 1/10th scale prototype version of CHIME and is designed to detect the BAO feature and constrain the distance-redshift relation. The lessons learned from its implementation will be used to inform and improve the final CHIME design.

  5. Overhead View of Area Surrounding Pathfinder

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Overhead view of the area surrounding the Pathfinder lander illustrating the Sojourner traverse. Red rectangles are rover positions at the end of sols 1-30. Locations of soil mechanics experiments, wheel abrasion experiments, and APXS measurements are shown. The A numbers refer to APXS measurements as discussed in the paper by Rieder et al. (p. 1770, Science Magazine, see image note). Coordinates are given in the LL frame.

    The photorealistic, interactive, three-dimensional virtual reality (VR) terrain models were created from IMP images using a software package developed for Pathfinder by C. Stoker et al. as a participating science project. By matching features in the left and right camera, an automated machine vision algorithm produced dense range maps of the nearfield, which were projected into a three-dimensional model as a connected polygonal mesh. Distance and angle measurements can be made on features viewed in the model using a mouse-driven three-dimensional cursor and a point-and-click interface. The VR model also incorporates graphical representations of the lander and rover and the sequence and spatial locations at which rover data were taken. As the rover moved, graphical models of the rover were added for each position that could be uniquely determined using stereo images of the rover taken by the IMP. Images taken by the rover were projected into the model as two-dimensional 'billboards' to show the proper perspective of these images.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  6. Imaging axon pathfinding in zebrafish in vivo.

    PubMed

    Leung, Louis; Holt, Christine E

    2012-09-01

    Axon pathfinding in the developing animal involves a highly dynamic process in which the axonal growth cone makes continuous decisions as it navigates toward its target. Changes occurring in the growth cone with respect to retracting from or extending into complex new territories can occur in minutes. Thus, the advent of strategies to visualize axon path-finding in vivo in a live intact animal is crucial for a better understanding of how the growth cone makes such rapid decisions in response to multiple cues. Combining these strategies with loss-of-function and/or gain-of-function techniques, one can gain some insight as to which molecules are crucial to particular growth cone behaviors at specific choice points during navigation. The major advantage of using zebrafish lies in the accessibility of major axon tracts for live microscopy, as their embryonic development occurs ex utero. Furthermore, the robust embryos remain healthy during immobilization and allow for good imaging for long periods. This protocol describes the method for stabilizing and preparing live zebrafish embryos for imaging labeled axonal tracts at high spatial and temporal resolution for up to 72 h. It has been used for retinotectal axon pathfinding, but can be adapted to visualize other axon tracts of interest. PMID:22949713

  7. Great Barrier Reef

    Atmospheric Science Data Center

    2013-04-16

    ... reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was acquired by ... visible in this image is Whitsunday Island, with smaller islands and reefs extending southeast, parallel to the coast. These include ...

  8. Materials Adherence Experiment on Mars Pathfinder: Early results

    SciTech Connect

    Landis, G.A.; Jenkins, P.P.; Hunter, G.

    1997-12-31

    The Materials Adherence Experiment (MAE) on the Pathfinder Sojourner rover will measure the dust deposition rate. By August, the Sojourner Rover on Mars Pathfinder will have completed its primary mission, and the experiment will have data on dust deposition during the first three weeks of operation on Mars. This paper will present the initial data from the experiment. This will be the first presentation of the results from the Pathfinder MAE experiment.

  9. Benthic foraminifera baseline assemblages from a coastal nearshore reef complex on the central Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Johnson, Jamie; Perry, Chris; Smithers, Scott; Morgan, Kyle

    2016-04-01

    Declining water quality due to river catchment modification since European settlement (c. 1850 A.D.) represents a major threat to the health of coral reefs on Australia's Great Barrier Reef (GBR), particularly for those located in the coastal waters of the GBR's inner-shelf. These nearshore reefs are widely perceived to be most susceptible to declining water quality owing to their close proximity to river point sources. Despite this, nearshore reefs have been relatively poorly studied with the impacts and magnitudes of environmental degradation still remaining unclear. This is largely due to ongoing debates concerning the significance of increased sediment yields against naturally high background sedimentary regimes. Benthic foraminifera are increasingly used as tools for monitoring environmental and ecological change on coral reefs. On the GBR, the majority of studies have focussed on the spatial distributions of contemporary benthic foraminiferal assemblages. While baseline assemblages from other environments (e.g. inshore reefs and mangroves) have been described, very few records exist for nearshore reefs. Here, we present preliminary results from the first palaeoecological study of foraminiferal assemblages of nearshore reefs on the central GBR. Cores were recovered from the nearshore reef complex at Paluma Shoals using percussion techniques. Recovery was 100%, capturing the entire Holocene reef sequence of the selected reef structures. Radiocarbon dating and subsequent age-depth modelling techniques were used to identify reef sequences pre-dating European settlement. Benthic foraminifera assemblages were reconstructed from the identified sequences to establish pre-European ecological baselines with the aim of providing a record of foraminiferal distribution during vertical reef accretion and against which contemporary ecological change may be assessed.

  10. Great Barrier Reef, Queensland, Australia

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This detailed view of the Great Barrier Reef, Queensland, Australia (19.5S, 149.5E) shows several small patch reefs within the overall reef system. The Great Barrier Reef, largest in the world, comprises thousands of individual reefs of great variety and are closely monitored by marine ecologists. These reefs are about 6000 years old and sit on top of much older reefs. The most rapid coral growth occurs on the landward side of the reefs.

  11. Results from the Mars Pathfinder camera.

    PubMed

    Smith, P H; Bell, J F; Bridges, N T; Britt, D T; Gaddis, L; Greeley, R; Keller, H U; Herkenhoff, K E; Jaumann, R; Johnson, J R; Kirk, R L; Lemmon, M; Maki, J N; Malin, M C; Murchie, S L; Oberst, J; Parker, T J; Reid, R J; Sablotny, R; Soderblom, L A; Stoker, C; Sullivan, R; Thomas, N; Tomasko, M G; Wegryn, E

    1997-12-01

    Images of the martian surface returned by the Imager for Mars Pathfinder (IMP) show a complex surface of ridges and troughs covered by rocks that have been transported and modified by fluvial, aeolian, and impact processes. Analysis of the spectral signatures in the scene (at 440- to 1000-nanometer wavelength) reveal three types of rock and four classes of soil. Upward-looking IMP images of the predawn sky show thin, bluish clouds that probably represent water ice forming on local atmospheric haze (opacity approximately 0.5). Haze particles are about 1 micrometer in radius and the water vapor column abundance is about 10 precipitable micrometers. PMID:9388170

  12. Mars pathfinder Rover egress deployable ramp assembly

    NASA Technical Reports Server (NTRS)

    Spence, Brian R.; Sword, Lee F.

    1996-01-01

    The Mars Pathfinder Program is a NASA Discovery Mission, led by the Jet Propulsion Laboratory, to launch and place a small planetary Rover for exploration on the Martian surface. To enable safe and successful egress of the Rover vehicle from the spacecraft, a pair of flight-qualified, deployable ramp assemblies have been developed. This paper focuses on the unique, lightweight deployable ramp assemblies. A brief mission overview and key design requirements are discussed. Design and development activities leading to qualification and flight systems are presented.

  13. Mars Pathfinder Wheel Abrasion Experiment Ground Test

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Siebert, Mark W.

    1998-01-01

    The National Aeronautics and Space Administration (NASA) sent a mission to the martian surface, called Mars Pathfinder. The mission payload consisted of a lander and a rover. The primary purpose of the mission was demonstrating a novel entry, descent, and landing method that included a heat shield, a parachute, rockets, and a cocoon of giant air bags. Once on the surface, the spacecraft returned temperature measurements near the Martian surface, atmosphere pressure, wind speed measurements, and images from the lander and rover. The rover obtained 16 elemental measurements of rocks and soils, performed soil-mechanics, atmospheric sedimentation measurements, and soil abrasiveness measurements.

  14. MAXIM Pathfinder x-ray interferometry mission

    NASA Astrophysics Data System (ADS)

    Gendreau, Keith C.; Cash, Webster C.; Shipley, Ann F.; White, Nicholas

    2003-03-01

    The MAXIM Pathfinder (MP) mission is under study as a scientific and technical stepping stone for the full MAXIM X-ray interferometry mission. While full MAXIM will resolve the event horizons of black holes with 0.1 microarcsecond imaging, MP will address scientific and technical issues as a 100 microarcsecond imager with some capabilities to resolve microarcsecond structure. We will present the primary science goals of MP. These include resolving stellar coronae, distinguishing between jets and accretion disks in AGN. This paper will also present the baseline design of MP. We will overview the challenging technical requirements and solutions for formation flying, target acquisition, and metrology.

  15. Mars PathFinder Rover Traverse Image

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This figure contains an azimuth-elevation projection of the 'Gallery Panorama.' The original Simple Cylindrical mosaic has been reprojected to the inside of a sphere so that lines of constant azimuth radiate from the center and lines of constant elevation are concentric circles. This projection preserves the resolution of the original panorama. Overlaid onto the projected Martian surface is a delineation of the Sojourner rover traverse path during the 83 Sols (Martian days) of Pathfinder surface operations. The rover path was reproduced using IMP camera 'end of day' and 'Rover movie' image sequences and rover vehicle telemetry data as references.

  16. Coral reef ecosystem decline: changing dynamics of coral reef carbonate production and implications for reef growth potential

    NASA Astrophysics Data System (ADS)

    Perry, Chris

    2016-04-01

    Global-scale deteriorations in coral reef health have caused major shifts in species composition and are likely to be exacerbated by climate change. It has been suggested that one effect of these ecological changes will be to lower reef carbonate production rates, which will impair reef growth potential and, ultimately, may lead to states of net reef erosion. However, quantitative data to support such assertions are limited, and linkages between the ecological state of coral reefs and their past and present geomorphic performance (in other words their growth potential) are poorly resolved. Using recently collected data from sites in the Caribbean and Indian Ocean, and which have undergone very different post-disturbance ecological trajectories over the last ~20-30 years, the differential impacts of disturbance on contemporary carbonate production regimes and on reef growth potential can be explored. In the Caribbean, a region which has been severely impacted ecological over the last 30+ years, our datasets show that average carbonate production rates on reefs are now less than 50% of pre-disturbance rates, and that calculated accretion rates (mm yr-1) are an about order of magnitude lower within shallow water habitats compared to Holocene averages. Collectively, these data suggest that recent ecological declines are now propagating through the system to impact on the geomorphic performance of Caribbean reefs and will impair their future growth potential. In contrast, the carbonate budgets of most reefs across the Chagos archipelago (central Indian Ocean), which is geographically remote and largely isolated from direct human disturbances, have recovered rapidly from major past disturbances (specifically the 1998 coral bleaching event). The carbonate budgets on these remote reefs now average +3.7 G (G = kg CaCO3 m-2 yr-1). Most significantly the production rates on Acropora-dominated reefs, which were most severely impacted by the 1998 bleaching event, average +8.4 G

  17. Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO)

    NASA Technical Reports Server (NTRS)

    McCormick, M. Patrick; Winker, David M.

    1998-01-01

    This paper will describe the planned 3-year Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission, its instrumentation and implementation. It will use LITE and other data, plus analyses, to show the feasibility of such a mission. PICASSO is being proposed for NASA's Earth System Science Pathfinder (ESSP) program with launch predicted in 2003.

  18. Primary Foreign Language Pathfinders: The Brighton and Hove Experience

    ERIC Educational Resources Information Center

    Enever, Janet; Watts, Catherine

    2009-01-01

    This article reports on a two-year project located within one local authority (LA), Brighton and Hove City Council, which was selected in 2003 to become a Primary Foreign Language Pathfinder. The main aim of this Pathfinder was to work with 18 other LAs across the country to pilot fresh approaches towards delivering foreign languages in the…

  19. Pathfinder on lakebed rolling out for test flight

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Pathfinder research aircraft's wing structure is clearly defined in this photo as personnel from AeroVironment rolled it out onto the lakebed at NASA's Dryden Flight Research Center, Edwards, California, for another test flight. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  20. The Australian SKA Pathfinder (ASKAP) software architecture

    NASA Astrophysics Data System (ADS)

    Guzman, Juan C.; Humphreys, Ben

    2010-07-01

    The Australian SKA Pathfinder (ASKAP) is a 1% Square Kilometre Array (SKA) pathfinder radio telescope, comprising of 36 12-metre diameter reflector antennas, each with a Focal Plane Array consisting of approximately 100 dualpolarised elements operating at centimetre wavelengths and yielding a wide field-of-view (FOV) on the sky of about 30 square degrees. ASKAP is currently under construction and will be located in the remote radio-quiet desert Midwest region of Western Australia. It is expected to be fully operational in 2013. Key challenges include near real-time processing of large amount of data (~ 4 GB/s), control and monitoring of widely distributed devices (approx. 150,000 monitoring I/O points) and remote semi-automated operations. After evaluating several software technologies we have decided to use the EPICS framework for the Telescope Operating System and the Internet Communications Engine (ICE) middleware for the high-level service bus. This paper presents a summary of the overall ASKAP software architecture, as well as describing how EPICS and ICE technologies fit in the control software design.

  1. Imaging axon pathfinding in Xenopus in vivo.

    PubMed

    Leung, Louis; Holt, Christine E

    2012-09-01

    Axon pathfinding in the developing animal involves a highly dynamic process in which the axonal growth cone makes continuous decisions as it navigates toward its target. Changes occurring in the growth cone with respect to retracting from or extending into complex new territories can occur in minutes. Thus, the advent of strategies to visualize axon path-finding in vivo in a live intact animal is crucial for a better understanding of how the growth cone makes such rapid decisions in response to multiple cues. Combining these strategies with loss-of-function and/or gain-of-function techniques allows one to gain some insight as to which molecules are crucial to particular growth cone behaviors at specific choice points during navigation. The main advantage of using Xenopus lies in the accessibility of major axon tracts for live microscopy, as their embryonic development occurs ex utero. Furthermore, the robust embryos remain healthy during immobilization and allow for good imaging for long periods. This protocol describes the methods for stabilizing and preparing live Xenopus embryos for imaging labeled axonal tracts at high spatial and temporal resolution for up to 72 h. This approach can been used to investigate how the knockdown of certain gene functions can affect the speed of navigation through the well-studied Xenopus retinotectal pathway. It can be adapted to visualize other axon tracts of interest. PMID:22949712

  2. Overhead View of Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Planimetric (overhead view) map of the landing site, to a distance of 20 meters from the spacecraft. North is at the top in this and Plates 3-5. To produce this map, images were geometrically projected onto an assumed mean surface representing the ground. Features above the ground plane (primarily rocks) therefore appear displaced radially outward; the amount of distortion increases systematically with distance. The upper surfaces of the lander and rover also appear enlarged and displaced because of their height. Primary grid (white) is based on the Landing Site Cartographic (LSC) coordinate system, defined with X eastward, Y north, and Z up, and origin located at the mean ground surface immediately beneath the deployed position of the IMP camera gimbal center. Secondary ticks (cyan) are based on the Mars local level (LL) frame, which has X north, Y east, Z down, with origin in the center of the lander baseplate. Rover positions (including APXS measurements) are commonly reported in the LL frame. Yellow grid shows polar coordinates based on the LSC system. Cartographic image processing by U.S. Geological Survey.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  3. Life and death on the coral reef: an ecological perspective on scholarly publishing in the health sciences*†

    PubMed Central

    Forsman, Rick B.

    2005-01-01

    Objective: Reflecting patterns evident in past Janet Doe lectures, the 2004 address draws on the foundations of biology to provide a model that offers insights into the advent of electronic publications and choices for the future. Setting: The lecture sketches a picture of the fragile relationships found in complex ecosystems and illustrates how such interdependencies function in the environment of the coral reef. Analysis: Deriving lessons from the marine world, the lecture then shifts to a description of similarities in the realm of scholarly publishing, the impact of digital innovations in the marketplace, and the controversies and choices inherent in open access publications. Conclusions: Lessons from ecology and publishing lead to the conclusion that librarians must take action and risks in this time of dramatic environmental change. PMID:15685268

  4. Journey to the Reef

    ERIC Educational Resources Information Center

    Bryson, Linda

    2010-01-01

    Despite their experiences with a cartoon sponge, most elementary students know little about the diverse inhabitants of coral reefs. Therefore, with vivid photography and video, diverse coral reef inhabitants were brought to life for the author's fifth-grade students. Students shared their knowledge in language arts and even explored coral reefs in…

  5. Imager for Mars Pathfinder (IMP) image calibration

    USGS Publications Warehouse

    Reid, R.J.; Smith, P.H.; Lemmon, M.; Tanner, R.; Burkland, M.; Wegryn, E.; Weinberg, J.; Marcialis, R.; Britt, D.T.; Thomas, N.; Kramm, R.; Dummel, A.; Crowe, D.; Bos, B.J.; Bell, J.F., III; Rueffer, P.; Gliem, F.; Johnson, J. R.; Maki, J.N.; Herkenhoff, K. E.; Singer, Robert B.

    1999-01-01

    The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of the mission. Image calibration algorithms were developed for landed operations to correct instrumental sources of noise and to calibrate images relative to observations of the radiometric targets. The uncertainties associated with these algorithms as well as current improvements to image calibration are discussed. Copyright 1999 by the American Geophysical Union.

  6. 360 Degree Panorama Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the first contiguous, uniform 360-degree color panorama taken by the Imager for Mars Pathfinder (IMP) over the course of sols 8, 9, and 10 (Martian days). Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama. At left is a lander petal and a metallic mast which is a portion of the low-gain antenna. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock Barnacle Bill, which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large rock Yogi. Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, and appeared more like the common basalts found on Earth. The tracks and circular pattern in the soil leading up to Yogi were part of Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the wheels in order to determine physical properties of the soil. During its traverse to Yogi the rover stirred the soil and exposed material from several centimeters in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer, the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to the rock Scooby Doo, and such white material may underlie much of the site. Deflated airbags are visible at the perimeter of all three lander petals. The IMP is a stereo imaging system with color

  7. Mars Pathfinder airbag impact attenuation system

    SciTech Connect

    Waye, D.E.; Cole, J.K.; Rivellini, T.P.

    1995-04-01

    The Mars Pathfinder spacecraft, scheduled for launch in November 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teamed to design, fabricate, test and validate a prototype 0.38 scale model of an airbag impact attenuation system. A computer code was developed to predict the performance of the airbag system. A test program in Sandia`s High Altitude Chamber was performed to validate the code and demonstrate the feasibility of the airbag concept and design. In addition, freefall tests were performed at representative velocities to demonstrate the structural integrity of the airbag system design. The feasibility program demonstrated that the airbag impact attenuation design will protect the lander upon impact with the Martian surface.

  8. Electrostatic Charging of the Pathfinder Rover

    NASA Technical Reports Server (NTRS)

    Siebert, Mark W.; Kolecki, Joseph C.

    1996-01-01

    The Mars Pathfinder mission will send a lander and a rover to the martian surface. Because of the extremely dry conditions on Mars, electrostatic charging of the rover is expected to occur as it moves about. Charge accumulation may result in high electrical potentials and discharge through the martian atmosphere. Such discharge could interfere with the operation of electrical elements on the rover. A strategy was sought to mitigate this charge accumulation as a precautionary measure. Ground tests were performed to demonstrate charging in laboratory conditions simulating the surface conditions expected at Mars. Tests showed that a rover wheel, driven at typical rover speeds, will accumulate electrical charge and develop significant electrical potentials (average observed, 110 volts). Measurements were made of wheel electrical potential, and wheel capacitance. From these quantities, the amount of absolute charge was estimated. An engineering solution was developed and recommended to mitigate charge accumulation. That solution has been implemented on the actual rover.

  9. Java PathFinder User Guide

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus

    1999-01-01

    The JAVA PATHFINDER, JPF, is a translator from a subset of JAVA 1.0 to PROMELA, the programming language of the SPIN model checker. The purpose of JPF is to establish a framework for verification and debugging of JAVA programming based on model checking. The main goal is to automate program verification such that a programmer can apply it in the daily work without the need for a specialist to manually reformulate a program into a different notation in order to analyze the program. The system is especially suited for analyzing multi-threaded JAVA applications, where normal testing usually falls short. The system can find deadlocks and violations of boolean assertions stated by the programmer in a special assertion language. This document explains how to Use JPF.

  10. Model Checking JAVA Programs Using Java Pathfinder

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Pressburger, Thomas

    2000-01-01

    This paper describes a translator called JAVA PATHFINDER from JAVA to PROMELA, the "programming language" of the SPIN model checker. The purpose is to establish a framework for verification and debugging of JAVA programs based on model checking. This work should be seen in a broader attempt to make formal methods applicable "in the loop" of programming within NASA's areas such as space, aviation, and robotics. Our main goal is to create automated formal methods such that programmers themselves can apply these in their daily work (in the loop) without the need for specialists to manually reformulate a program into a different notation in order to analyze the program. This work is a continuation of an effort to formally verify, using SPIN, a multi-threaded operating system programmed in Lisp for the Deep-Space 1 spacecraft, and of previous work in applying existing model checkers and theorem provers to real applications.

  11. Pathfinder autonomous rendezvous and docking project

    NASA Technical Reports Server (NTRS)

    Lamkin, Stephen (Editor); Mccandless, Wayne (Editor)

    1990-01-01

    Capabilities are being developed and demonstrated to support manned and unmanned vehicle operations in lunar and planetary orbits. In this initial phase, primary emphasis is placed on definition of the system requirements for candidate Pathfinder mission applications and correlation of these system-level requirements with specific requirements. The FY-89 activities detailed are best characterized as foundation building. The majority of the efforts were dedicated to assessing the current state of the art, identifying desired elaborations and expansions to this level of development and charting a course that will realize the desired objectives in the future. Efforts are detailed across all work packages in developing those requirements and tools needed to test, refine, and validate basic autonomous rendezvous and docking elements.

  12. Modal analysis of PATHFINDER unmanned air vehicle

    SciTech Connect

    Woehrle, T.G.; Costerus, B.W.; Lee, C.L.

    1994-10-19

    An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal data was taken from 92 measurement locations on the aircraft using newly designed, lightweight, tri-axial accelerometers. A conventional PC-based data acquisition system provided data handling. Modal parameters were calculated, and animated mode shapes were produced using SMS STARStruct{trademark} Modal Analysis System software. The modal parameters will be used for validation of finite element models, optimum placement of onboard accelerometers during flight testing, and vibration isolation design of sensor platforms.

  13. Mars Pathfinder Airbag Impact Attenuation System

    NASA Technical Reports Server (NTRS)

    Waye, Donald; Cole, J. Kenneth; Rivellini, Tommaso P.

    1995-01-01

    The Mars Pathfinder spacecraft, scheduled for launch in December 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teamed to design, fabricate, test and validate a prototype 0.38 scale model of an airbag impact attenuation system. A computer code was developed to predict the performance of the airbag system. A test program in Sandia's High Altitude Chamber was performed to validate the code and demonstrate the feasibility of the airbag concept and design. In addition, freefall tests were performed at representative velocities to demonstrate the structural integrity of the airbag system design. The feasibility program demonstrated that the airbag impact attenuation design will protect the lander upon impact with the Martian surface.

  14. Statechart Analysis with Symbolic PathFinder

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina S.

    2012-01-01

    We report here on our on-going work that addresses the automated analysis and test case generation for software systems modeled using multiple Statechart formalisms. The work is motivated by large programs such as NASA Exploration, that involve multiple systems that interact via safety-critical protocols and are designed with different Statechart variants. To verify these safety-critical systems, we have developed Polyglot, a framework for modeling and analysis of model-based software written using different Statechart formalisms. Polyglot uses a common intermediate representation with customizable Statechart semantics and leverages the analysis and test generation capabilities of the Symbolic PathFinder tool. Polyglot is used as follows: First, the structure of the Statechart model (expressed in Matlab Stateflow or Rational Rhapsody) is translated into a common intermediate representation (IR). The IR is then translated into Java code that represents the structure of the model. The semantics are provided as "pluggable" modules.

  15. The Imager for Mars Pathfinder Insurance Pan

    NASA Technical Reports Server (NTRS)

    Herkenhoff, K. E.; Johnson, J. R.; Weller, L. A.

    2003-01-01

    The Imager for Mars Pathfinder (IMP) obtained a full panorama of the Sagan Memorial Station landing site on Sol 2, before the IMP mast was deployed. The images in this panorama were taken in 4 filters (including stereo) and losslessly compressed to provide a high-quality multispectral survey of the landing site even if the IMP mast did not successfully deploy; this data set was therefore called the Insurance Pan. It was completed late in the afternoon of Sol 2, just before the IMP mast was (successfully) deployed. The data were stored in memory and returned to Earth after it became clear that downlink rates were higher than expected. The Insurance Pan horizontal (azimuth) coverage is nearly complete, with gaps caused by pointing errors and data packet losses. Stereo data were acquired in the blue (445 nm) filter, as well as right-eye green (531 nm), orange (600 nm), and near-infrared (752 nm) data.

  16. JWST Pathfinder Telescope Risk Reduction Cryo Test Program

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Scorse, Thomas R.; Spina, John A.; Noel, Darin M.; Havey, Keith A., Jr.; Huguet, Jesse A.; Whitman, Tony L.; Wells, Conrad; Walker, Chanda B.; Lunt, Sharon; Hadaway, James B.; Keski-Kuha, Ritva; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Marsh, James M.

    2015-01-01

    In 2014, the Optical Ground Support Equipment was integrated into the large cryo vacuum chamber at Johnson Space Center (JSC) and an initial Chamber Commissioning Test was completed. This insured that the support equipment was ready for the three Pathfinder telescope cryo tests. The Pathfinder telescope which consists of two primary mirror segment assemblies and the secondary mirror was delivered to JSC in February 2015 in support of this critical risk reduction test program prior to the flight hardware. This paper will detail the Chamber Commissioning and first optical test of the JWST Pathfinder telescope.

  17. JWST pathfinder telescope risk reduction cryo test program

    NASA Astrophysics Data System (ADS)

    Matthews, Gary W.; Scorse, Thomas R.; Spina, John A.; Noël, Darin M.; Havey, Keith A.; Huguet, Jesse A.; Whitman, Tony L.; Wells, Conrad; Walker, Chanda B.; Lunt, Sharon; Hadaway, James B.; Keski-Kuha, Ritva; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Marsh, James M.

    2015-08-01

    In 2014, the Optical Ground Support Equipment was integrated into the large cryo vacuum chamber at Johnson Space Center (JSC) and an initial Chamber Commissioning Test was completed. This insured that the support equipment was ready for the three Pathfinder telescope cryo tests. The Pathfinder telescope which consists of two primary mirror segment assemblies and the secondary mirror was delivered to JSC in February 2015 in support of this critical risk reduction test program prior to the flight hardware. This paper will detail the Chamber Commissioning and first optical test of the JWST Pathfinder telescope.

  18. Exobiology site priorities for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Farmer, Jack D.; Desmarais, David J.

    1994-01-01

    The fact that life developed on the Earth within the first billion years of its history makes it quite plausible that life may have also developed on Mars. If life did develop on Mars, it undoubtedly left behind a fossil record. Such a fossil record is likely to be more accessible than either subsurface environments that may harbor life, or scattered 'oases' that may be present at the surface. Consequently, the post-Viking approach of Mars exobiology has shifted focus to search for evidence of an ancient martian biosphere. This has led to the emergence of a new subdiscipline of paleontology, herein termed 'exopaleontology', which deals with the exploration for fossils on other planets and whose core concepts derive from Earth-based Precambrian paleontology, microbial ecology, and sedimentology. Potential targets on Mars for subaqueous spring deposits, sedimentary cements, and evaporites are ancient terminal lake basins where hydrological systems could have endured for some time under arid conditions. Potential targets for the Mars Pathfinder mission include channeled impact craters and areas of deranged drainage associated with outflows in northwest Arabia and Xanthe Terra, where water may have ponded temporarily to form lakes. The major uncertainty of such targets is their comparatively younger age and the potentially short duration of hydrological activity compared to older paleolake basins found in the southern hemisphere. However, it has been suggested that cycles of catastrophic flooding associated with Tharsis volcanism may have sustained a large body of water, Oceanus Borealis, in the northern plains area until quite late in martian history. Although problematic, the shoreline areas of the proposed northern ocean provide potential targets for a Mars Pathfinder mission aimed at exploring for carbonates or other potentially fossiliferous marine deposits. Carbonates and evaporites possess characteristic spectra signatures in the near-infrared and should be

  19. The CO Mapping Array Pathfinder (COMAP)

    NASA Astrophysics Data System (ADS)

    Cleary, Kieran; Bigot-Sazy, Marie-Anne; Chung, Dongwoo; Church, Sarah E.; Dickinson, Clive; Eriksen, Hans; gaier, todd; Goldsmith, Paul; Gundersen, Joshua O.; Harper, Stuart; Harris, Andrew I.; Lamb, James; Li, Tony; Munroe, Ryan; Pearson, Timothy J.; Readhead, Anthony C. S.; Wechsler, Risa H.; Kathrine Wehus, Ingunn; Woody, David

    2016-01-01

    The CO Mapping Array Pathfinder (COMAP) will open a new window on both the Epoch of Reionization (EoR) and the Epoch of Galaxy Assembly by using carbon monoxide (CO) lines to trace the distribution of star-forming galaxies in both epochs. Phase I of COMAP comprises a 10-m telescope, located at the Owens Valley Radio Observatory (OVRO), equipped with a 19-pixel spectrometer array that will map a total of 10 square degrees of sky in the frequency range 30-34 GHz, with spectral resolution R~800. This band will be sensitive to CO(1-0) in the redshift slice z=2.4-2.8 and to CO(2-1) in the redshift slice z = 5.8-6.7.Constraining the CO power spectrum from the EoR will ultimately require measurements at multiple frequencies and arrays with hundreds of elements. The aim of this pathfinder experiment is to i) demonstrate the feasibility and future potential of wide-field CO intensity mapping, and ii) provide a test-bed for the technology development and observational strategies. Phase I of COMAP will focus on constraining the CO power spectrum from the Epoch of Galaxy Assembly, at z=2.4-2.8. A wide range of predictions for the strength of this power spectrum have appeared in the literature; much of this range can either be confirmed or ruled out by COMAP.Cross-correlation with galaxy surveys in this redshift range will allow us to disentangle the impact of cosmological parameters, star formation rate (SFR) and the CO-SFR connection. Cross-correlation will also establish confidence that the observed signal is CO and allow inferences to be drawn about the unobserved, but CO-luminous galaxy population. The COMAP fields will therefore be chosen to overlap with galaxy surveys.COMAP Phase I observations are planned to start in late 2017, continuing until late 2019.

  20. The magnetic properties experiments on Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Madsen, M. B.; Hviid, S. F.; Gunnlaugsson, H. P.; Knudsen, J. M.; Goetz, W.; Pedersen, C. T.; Dinesen, A. R.; Mogensen, C. T.; Olsen, M.; Hargraves, R. B.

    1999-04-01

    The Mars Pathfinder lander carried two magnet arrays, each containing five small permanent magnets of varying strength. The magnet arrays were passively exposed to the wind borne dust on Mars. By the end of the Mars Pathfinder mission a bull's-eye pattern was visible on the four strongest magnets of the arrays showing the presence of magnetic dust particles. From the images we conclude that the dust suspended in the atmosphere is not solely single phase particles of hematite (α-Fe2O3) and that single phase particles of the ferrimagnetic minerals maghemite (γ-Fe2O3) or magnetite (Fe3O4) are not present as free particles in any appreciable amount. The material on the strongest magnets seems to be indistinguishable from the bright surface material around the lander. From X-ray fluorescence it is known that the soil consists mainly of silicates. The element iron constitutes about 13% of the soil. The particles in the airborne dust seem to be composite, containing a few percent of a strongly magnetic component. We conclude that the magnetic phase present in the airborne dust particles is most likely maghemite. The particles thus appear to consist of silicate aggregates stained or cemented by ferric oxides, some of the stain and cement being maghemite. These results imply that Fe2+ ions were leached from the bedrock, and after passing through a state as free Fe2+ ions in liquid water, the Fe2+ was oxidized to Fe3+ and then precipitated. It cannot, however, be ruled out that the magnetic particles are titanomagnetite (or titanomaghemite) occurring in palagonite, having been inherited directly from the bedrock.

  1. Topographic Map of Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Topographic map of the landing site, to a distance of 60 meters from the lander in the LSC coordinate system. The lander is shown schematically in the center; 2.5 meter radius circle (black) centered on the camera was not mapped. Gentle relief [root mean square (rms) elevation variation 0.5 m; rms a directional slope 4O] and organization of topography into northwest and northeast-trending ridges about 20 meters apart are apparent. Roughly 30% of the illustrated area is hidden from the camera behind these ridges. Contours (0.2 m interval) and color coding of elevations were generated from a digital terrain model, which was interpolated by kriging from approximately 700 measured points. Angular and parallax point coordinates were measured manually on a large (5 m length) anaglyphic uncontrolled mosaic and used to calculate Cartesian (LSC) coordinates. Errors in azimuth on the order of 10 are therefore likely; elevation errors were minimized by referencing elevations to the local horizon. The uncertainty in range measurements increases quadratically with range. Given a measurement error of 1/2 pixel, the expected precision in range is 0.3 meter at 10 meter range, and 10 meters at 60 meter range. Repeated measurements were made, compared, and edited for consistency to improve the range precision. Systematic errors undoubtedly remain and will be corrected in future maps compiled digitally from geometrically controlled images. Cartographic processing by U.S. Geological Survey.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  2. Linking Wave Forcing to Coral Cover and Structural Complexity Across Coral Reef Flats

    NASA Astrophysics Data System (ADS)

    Harris, D. L.; Rovere, A.; Parravicini, V.; Casella, E.

    2015-12-01

    The hydrodynamic regime is a significant component in the geomorphic and ecological development of coral reefs. The energy gradients and flow conditions generated by the breaking and transformation of waves across coral reef crests and flats drive changes in geomorphic structure, and coral growth form and distribution. One of the key aspects in regulating the wave energy propagating across reef flats is the rugosity or roughness of the benthic substrate. Rugosity and structural complexity of coral reefs is also a key indicator of species diversity, ecological functioning, and reef health. However, the links between reef rugosity, coral species distribution and abundance, and hydrodynamic forcing are poorly understood. In this study we examine this relationship by using high resolution measurement of waves in the surf zone and coral reef benthic structure.Pressure transducers (logging at 4 Hz) were deployed in cross reef transects at two sites (Tiahura and Ha'apiti reef systems) in Moorea, French Polynesia with wave characteristics determined on a wave by wave basis. A one dimensional hydrodynamic model (XBeach) was calibrated from this data to determine wave processes on the reef flats under average conditions. Transects of the reef benthic structure were conducted using photographic analysis and the three dimensional reef surface was constructed using structure from motion procedures. From this analysis reef rugosity, changes in coral genus and growth form, and across reef shifts in benthic community were determined. The results show clear changes in benthic assemblages along wave energy gradients with some indication of threshold values of wave induced bed shear stress above which live coral cover was reduced. Reef rugosity was shown to be significantly along the cross-reef transect which has important implications for accurate assessment of wave dissipation across coral reef flats. Links between reef rugosity and coral genus were also observed and may indicate

  3. LISA Pathfinder paves way for gravitational-wave probe

    NASA Astrophysics Data System (ADS)

    Johnston, Hamish

    2016-07-01

    Researchers working on the LISA Pathfinder space mission have successfully managed to isolate from the environment two 2 kg test masses at a special “Lagrangian point” between the Earth and the Sun.

  4. Dust on Mars: Materials Adherence Experiment results from Mars Pathfinder

    SciTech Connect

    Landis, G.A.; Jenkins, P.P.

    1997-12-31

    Mars Pathfinder is the first solar-powered probe to operate on the surface of Mars. Pathfinder consists of a lander and a small, autonomous, six-wheel solar-powered rover, Sojourner. The Pathfinder spacecraft reflects NASA`s new philosophy of exploiting new technologies to reduce mission cost. The Materials Adherence Experiment on Pathfinder was designed to measure the degradation of solar arrays due to dust settling out of the atmosphere and blocking light to the solar array, lowering the array power output. The MAE measurements indicate steady dust accumulation at a rate of about 0.28% per day. This value is consistent with the performance of the solar arrays, which have decreased in power at an estimated rate of 0.29% per day.

  5. Operations and Autonomy of the Mars Pathfinder Microrover

    NASA Technical Reports Server (NTRS)

    Mishkin, A. H.; Morrison, J. C.; Nguyen, T. T.; Stone, H. W.; Cooper, B. K.

    1998-01-01

    The Microrover Flight Experiment (MFEX) is a NSAS OACT (Office of Advanced Concepts and Technology) flight experiment which, integrated with the Mars Pathfinder (MPF) lander and spacecraft system, landed on Mars on July 4, 1997.

  6. Immersive Environments for Mission Operations: Beyond Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Wright, J.; Hartman, F.; Cooper, B.

    1998-01-01

    Immersive environments are just beginning to be used to support mission operations at the Jet Propulsion Laboratory. This technology contributed to the Mars Pathfinder Mission in planning sorties for the Sojourner rover.

  7. Selection of the Mars Pathfinder landing site

    NASA Astrophysics Data System (ADS)

    Golombek, M. P.; Cook, R. A.; Moore, H. J.; Parker, T. J.

    1997-02-01

    The Mars Pathfinder spacecraft will land on a depositional fan near the mouth of the catastrophic outflow channel, Ares Vallis (19.5°N, 32.8°W). This site offers the prospect of analyzing a variety of rock types from the ancient cratered highlands, intermediate-age ridged plains, and reworked channel deposits. Analyses of these rocks by Pathfinder instruments will enable first-order scientific questions to be addressed, such as differentiation of the crust, the development of weathering products, and the nature of the early environment, as well as their subsequent evolution on Mars. Constraints imposed by (1) spacecraft and rover designs (which are robust), (2) entry, descent, and landing, (3) scientific potential at various sites, and (4) safety were important considerations in site selection. Engineering constraints require a 70 km by 200 km smooth, flat (low slopes) area located between 10° and 20°N that is below 0 km elevation, with average radar reflectivity, little dust, and moderate rock abundance. Three regions on Mars are between 10° and 20°N and below 0 km elevation: Chryse, Amazonis, and Isidis-Elysium. Science considerations favor sites at the mouths of outflow channels (grab bag sites offer an assay of rock types on Mars), highland sites (early crustal differentiation and climate), and sites covered with dark (unoxidized) material. Sites are considered safe if they are clearly below 0 km elevation, appear acceptably free of hazards in high-resolution (<50m/pixel) Viking orbiter images and have acceptable reflectivity and roughness at radar wavelengths, thermal inertia, rock abundance, red to violet ratio, and albedo. Recent 3.5-cm wavelength radar observations were used to verify elevation, reflectivity, and roughness within the landing ellipses. Three sites meet all of these criteria: Ares Vallis, Tritonis Lacus, and Isidis. Although Isidis appears to be safer than Tritonis and Ares, the greater scientific potential at Ares Vallis resulted in

  8. Bayesian model selection for LISA pathfinder

    NASA Astrophysics Data System (ADS)

    Karnesis, Nikolaos; Nofrarias, Miquel; Sopuerta, Carlos F.; Gibert, Ferran; Armano, Michele; Audley, Heather; Congedo, Giuseppe; Diepholz, Ingo; Ferraioli, Luigi; Hewitson, Martin; Hueller, Mauro; Korsakova, Natalia; McNamara, Paul W.; Plagnol, Eric; Vitale, Stefano

    2014-03-01

    The main goal of the LISA Pathfinder (LPF) mission is to fully characterize the acceleration noise models and to test key technologies for future space-based gravitational-wave observatories similar to the eLISA concept. The data analysis team has developed complex three-dimensional models of the LISA Technology Package (LTP) experiment onboard the LPF. These models are used for simulations, but, more importantly, they will be used for parameter estimation purposes during flight operations. One of the tasks of the data analysis team is to identify the physical effects that contribute significantly to the properties of the instrument noise. A way of approaching this problem is to recover the essential parameters of a LTP model fitting the data. Thus, we want to define the simplest model that efficiently explains the observations. To do so, adopting a Bayesian framework, one has to estimate the so-called Bayes factor between two competing models. In our analysis, we use three main different methods to estimate it: the reversible jump Markov chain Monte Carlo method, the Schwarz criterion, and the Laplace approximation. They are applied to simulated LPF experiments in which the most probable LTP model that explains the observations is recovered. The same type of analysis presented in this paper is expected to be followed during flight operations. Moreover, the correlation of the output of the aforementioned methods with the design of the experiment is explored.

  9. LISA Pathfinder as a micrometeorite instrument

    NASA Astrophysics Data System (ADS)

    Thorpe, James

    2016-03-01

    The Solar System contains a population of dust and small particles originating from asteroids, comets, and other bodies. These particles have been studied using a number of techniques ranging from in-situ satellite detectors to analysis of lunar microcraters to ground-based observations of zodiacal light. We describe an approach for using the LISA Pathfinder [LPF] mission as an instrument to detect and characterize the dynamics of dust particles in the vicinity of Earth-Sun L1. Launched on Dec. 3rd, 2015, LPF is a dedicated technology demonstrator mission that will validate several key technologies for a future space-based gravitational-wave observatory. The primary science instrument aboard LPF is a precision accelerometer which we show will be capable of sensing discrete momentum impulses as small as 4 × 10-8 N . s. We then estimate the rate of such impulses resulting from impacts of micrometeoroids based on standard models of the micrometeoroid environment in the inner solar system. We find that LPF may detect dozens to hundreds of individual events corresponding to impacts of particles with masses > 10-9 g during LPF's roughly six-month science operations phase.

  10. Data Analysis for the LISA Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Thorpe, James Ira

    2009-01-01

    The LTP (LISA Technology Package) is the core part of the Laser Interferometer Space Antenna (LISA) Pathfinder mission. The main goal of the mission is to study the sources of any disturbances that perturb the motion of the freely-falling test masses from their geodesic trajectories as well as 10 test various technologies needed for LISA. The LTP experiment is designed as a sequence of experimental runs in which the performance of the instrument is studied and characterized under different operating conditions. In order to best optimize subsequent experimental runs, each run must be promptly analysed to ensure that the following ones make best use of the available knowledge of the instrument ' In order to do this, all analyses must be designed and tested in advance of the mission and have sufficient built-in flexibility to account for unexpected results or behaviour. To support this activity, a robust and flexible data analysis software package is also required. This poster presents two of the main components that make up the data analysis effort: the data analysis software and the mock-data challenges used to validate analysis procedures and experiment designs.

  11. Status of the LISA Pathfinder LPF

    NASA Astrophysics Data System (ADS)

    Heinzel, G.; Ruediger, A.

    LISA Laser Interferometer Space Antenna is the joint Nasa ESA project for the detection of gravitational waves GWs It consists of three spacecraft in an equilateral triangle of 5 million km sides orbiting on an Earth-like orbit around the sun Each spacecraft houses two free-falling test masses that determine the distances to the other spacecraft Distance changes due to GWs are monitored by laser interferometry down to minute relative changes in the order of 10 -23 The extremely small GW signals make a technology demonstrator the LISA Pathfinder LPF very desirable to verify that the employed technologies of 1 laser stability 2 picometer interferometry 3 drag-free control and 4 micronewton thrusters can meet the challenge The LPF will be carried on the ESA Smart-2 mission to be placed near the Lagrange point L1 with launch expected for 2009 LPF will consist of one spacecraft with two independent test masses the distances between these two test masses and the position changes with respect to the optical bench spacecraft will be monitored with a resolution only one power of ten away from the requirements of LISA proper A flight module of the optical bench has been built and has passed the necessary tests for space qualification

  12. The Mars Pathfinder Mission and Science Results

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.

    1999-01-01

    Mars Pathfinder, the first low-cost, quick Discovery class mission to be completed, successfully landed on the surface of Mars on July 4, 1997, deployed and navigated a small rover, and collected data from 3 science instruments and 10 technology experiments. The mission operated on Mars for 3 months and returned 2.3 Gbits of new data, including over 16,500 lander and 550 rover images, 16 chemical analyses of rocks and soil, and 8.5 million individual temperature, pressure and wind measurements. The rover traversed 100 m clockwise around the lander, exploring about 200 square meters of the surface. The mission captured the imagination of the public, and garnered front page headlines during the first week. A total of about 566 million internet "hits" were registered during the first month of the mission, with 47 million "hits" on July 8th alone, making the Pathfinder landing by far the largest internet event in history at the time. Pathfinder was the first mission to deploy a rover on Mars. It carried a chemical analysis instrument, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which provided a calibration point or "ground truth" for orbital remote sensing observations. The combination of spectral imaging of the landing area by the lander camera, chemical analyses aboard the rover, and close-up imaging of colors, textures and fabrics with the rover cameras offered the potential of identifying rocks (petrology and mineralogy). With this payload, a landing site in Ares Vallis was selected because it appeared acceptably safe and offered the prospect of analyzing a variety of rock types expected to be deposited by catastrophic floods, which enabled addressing first-order scientific questions such as differentiation of the crust, the development of weathering products, and the nature of the early Martian environment and its subsequent evolution. The 3 instruments and rover allowed seven areas of scientific investigation: the

  13. The Mars Pathfinder Mission and Science Results

    NASA Astrophysics Data System (ADS)

    Golombek, M. P.

    1999-01-01

    Mars Pathfinder, the first low-cost, quick Discovery class mission to be completed, successfully landed on the surface of Mars on July 4, 1997, deployed and navigated a small rover, and collected data from 3 science instruments and 10 technology experiments. The mission operated on Mars for 3 months and returned 2.3 Gbits of new data, including over 16,500 lander and 550 rover images, 16 chemical analyses of rocks and soil, and 8.5 million individual temperature, pressure and wind measurements. The rover traversed 100 m clockwise around the lander, exploring about 200 square meters of the surface. The mission captured the imagination of the public, and garnered front page headlines during the first week. A total of about 566 million internet "hits" were registered during the first month of the mission, with 47 million "hits" on July 8th alone, making the Pathfinder landing by far the largest internet event in history at the time. Pathfinder was the first mission to deploy a rover on Mars. It carried a chemical analysis instrument, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which provided a calibration point or "ground truth" for orbital remote sensing observations. The combination of spectral imaging of the landing area by the lander camera, chemical analyses aboard the rover, and close-up imaging of colors, textures and fabrics with the rover cameras offered the potential of identifying rocks (petrology and mineralogy). With this payload, a landing site in Ares Vallis was selected because it appeared acceptably safe and offered the prospect of analyzing a variety of rock types expected to be deposited by catastrophic floods, which enabled addressing first-order scientific questions such as differentiation of the crust, the development of weathering products, and the nature of the early Martian environment and its subsequent evolution. The 3 instruments and rover allowed seven areas of scientific investigation: the

  14. Constellation Pathfinder: A University Nanosatellite Project

    NASA Astrophysics Data System (ADS)

    Spence, Harlan E.; Petschek, Harry E.

    2002-08-01

    Under the task of nanosatellite mission design, we developed a mission concept that enables hundreds of one-kilogram spacecraft to be placed into orbit with a single mothership. We performed trade studies to arrive at a positive feasibility assessment. The results of that study were described in two publications. Second, under the task of spacecraft design, we developed nanosatellite designs needed to enable constellation missions. Design studies were conducted and subsystems prototyped, including a spin-table and launcher concept for a small stack of nanosatellites. Engineering design studies of this work appeared in the refereed literature. Instruments to be flown on such a small craft have been specified and then developed as part of a related AF SBIR effort. Undergraduate students (>100 in the Aerospace Engineering, Mechanical Engineering, and Electrical and Computer Engineering departments) played an enormous role in the mission and spacecraft definitions of the Constellation Pathfinder project. In addition to five publications, numerous invited and contributed presentations of these studies have been presented at national and international meetings.

  15. New directions in coral reef microbial ecology.

    PubMed

    Garren, Melissa; Azam, Farooq

    2012-04-01

    Microbial processes largely control the health and resilience of coral reef ecosystems, and new technologies have led to an exciting wave of discovery regarding the mechanisms by which microbial communities support the functioning of these incredibly diverse and valuable systems. There are three questions at the forefront of discovery: What mechanisms underlie coral reef health and resilience? How do environmental and anthropogenic pressures affect ecosystem function? What is the ecology of microbial diseases of corals? The goal is to understand the functioning of coral reefs as integrated systems from microbes and molecules to regional and ocean-basin scale ecosystems to enable accurate predictions of resilience and responses to perturbations such as climate change and eutrophication. This review outlines recent discoveries regarding the microbial ecology of different microenvironments within coral ecosystems, and highlights research directions that take advantage of new technologies to build a quantitative and mechanistic understanding of how coral health is connected through microbial processes to its surrounding environment. The time is ripe for natural resource managers and microbial ecologists to work together to create an integrated understanding of coral reef functioning. In the context of long-term survival and conservation of reefs, the need for this work is immediate. PMID:21955796

  16. Reef Education Evaluation: Environmental Knowledge and Reef Experience

    ERIC Educational Resources Information Center

    Stepath, Carl M.

    2005-01-01

    Background: The Reef education evaluation: environmental knowledge and reef experience report concerns PhD research about marine education, and the investigation of learning with high school students and the effect of coral reef monitoring marine experiential education interventions. The effectiveness of classroom learning and reef trips were…

  17. Uncovering the connectivity of coral reef systems via Lagrangian Coherent Structures

    NASA Astrophysics Data System (ADS)

    Leclair, Matthieu; Lowe, Ryan; Zang, Zhenlin; Ivey, Gregory; Peacock, Thomas

    2015-04-01

    There has been a staggering decline in the health of coral reef ecosystems worldwide over the past century, driven by anthropogenic influences, natural processes, and overall climate change. The future of coral reefs depends largely on their ability to recover from catastrophic events, which in turn crucially relies on the ability of reef larval populations to supply and restore damaged reefs. Improving quantitative predictions of reef larval transport and connectivity has thus emerged as a high priority research area in coral reef science. Ocean circulation models are being increasingly utilized in conjunction with particle tracking methods to provide spatially explicit predictions of larval transport within reef systems. The current major drawback of this approach is that it does not elucidate the underlying yet dynamic flow structures that drive reef connectivity. Recently, however, novel Lagrangian-based analysis approaches have been developed to identify the hidden coherent structures that govern material transport in spatiotemporally complex flow fields. Here we apply these methods to investigate the connectivity within a complex coral reef system, using the UNESCO World Heritage Ningaloo Reef in Australia as a case study. Our study demonstrates how this new approach identifies the dominant flow structures present on the reef, thereby uncovering connectivity and advocating a new practical framework for investigating and understanding how ocean processes shape the ecological transport in and around coral reefs. The technique can prove particularly valuable in supporting the design of Marine Protected Areas that are intended to safeguard the future of coral reefs and other ocean ecosystems.

  18. Caribbean-wide decline in carbonate production threatens coral reef growth

    PubMed Central

    Perry, Chris T.; Murphy, Gary N.; Kench, Paul S.; Smithers, Scott G.; Edinger, Evan N.; Steneck, Robert S.; Mumby, Peter J.

    2013-01-01

    Global-scale deteriorations in coral reef health have caused major shifts in species composition. One projected consequence is a lowering of reef carbonate production rates, potentially impairing reef growth, compromising ecosystem functionality and ultimately leading to net reef erosion. Here, using measures of gross and net carbonate production and erosion from 19 Caribbean reefs, we show that contemporary carbonate production rates are now substantially below historical (mid- to late-Holocene) values. On average, current production rates are reduced by at least 50%, and 37% of surveyed sites were net erosional. Calculated accretion rates (mm year−1) for shallow fore-reef habitats are also close to an order of magnitude lower than Holocene averages. A live coral cover threshold of ~10% appears critical to maintaining positive production states. Below this ecological threshold carbonate budgets typically become net negative and threaten reef accretion. Collectively, these data suggest that recent ecological declines are now suppressing Caribbean reef growth potential. PMID:23360993

  19. Great Barrier Reef

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A better than average view of the Great Barrier Reef was captured by SeaWiFS on a recent overpass. There is sunglint northeast of the reef and there appears to be some sort of filamentous bloom in the Capricorn Channel.

  20. The Status of the Ultra Fast Flash Observatory - Pathfinder

    NASA Astrophysics Data System (ADS)

    Nam, J. W.; Ahmad, S.; Ahn, K. B.; Barrillon, P.; Brandt, S.; Budtz-Jrgensen, C.; Castro-Tirado, A. J.; Chang, C.-H.; Chang, C.-Y.; Chang, Y. Y.; Chen, C. R.; Chen, P.; Cho, M.; Choi, H. S.; Choi, Y. J.; Connel, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang, J. J.; Huang, M. H. A.; Jeong, S.; Jung, A.; Kim, J. E.; Kim, M. B.; Kim, S.-W.; Kim, Y. W.; Krasnov, A. S.; Lee, J.; Lim, H.; Linder, E. V.; Liu, T. C.; Lund, N.; Min, K. W.; Na, G. W.; Panasyuk, M. I.; Park, I. H.; Reglero, V.; Ripa, J.; Rodrigo, J. M.; Smoot, G. F.; Suh, J. E.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.

    2014-01-01

    The Ultra Fast Flash Observatory (UFFO) is a project to study early optical emissions from Gamma Ray Bursts (GRBs). The primary scientific goal of UFFO is to see if GRBs can be calibrated with their rising times, so that they could be used as new standard candles. In order to minimize delay in optical follow-up measurements, which is now about 100 sec after trigger from the Swift experiment, we rotate a mirror to redirect light path so that optical measurement can be performed within a second after the trigger. We have developed a pathfinder mission, UFFO-pathfinder to launch on board the Lomonosov satellite in 2012. In this talk, I will present scientific motivations and descriptions of the design and development of UFFO-pathfinder.

  1. Mars Pathfinder Rover-Lewis Research Center Technology Experiments Program

    NASA Technical Reports Server (NTRS)

    Stevenson, Steven M.

    1997-01-01

    An overview of NASA's Mars Pathfinder Program is given and the development and role of three technology experiments from NASA's Lewis Research Center and carried on the Mars Pathfinder rover is described. Two recent missions to Mars were developed and managed by the Jet Propulsion Laboratory, and launched late last year: Mars Global Surveyor in November 1996 and Mars Pathfinder in December 1996. Mars Global Surveyor is an orbiter which will survey the planet with a number of different instruments, and will arrive in September 1997, and Mars Pathfinder which consists of a lander and a small rover, landing on Mars July 4, 1997. These are the first two missions of the Mars Exploration Program consisting of a ten year series of small robotic martian probes to be launched every 26 months. The Pathfinder rover will perform a number of technology and operational experiments which will provide the engineering information necessary to design and operate more complex, scientifically oriented surface missions involving roving vehicles and other machinery operating in the martian environment. Because of its expertise in space power systems and technologies, space mechanisms and tribology, Lewis Research Center was asked by the Jet Propulsion Laboratory, which is heading the Mars Pathfinder Program, to contribute three experiments concerning the effects of the martian environment on surface solar power systems and the abrasive qualities of the Mars surface material. In addition, rover static charging was investigated and a static discharge system of several fine Tungsten points was developed and fixed to the rover. These experiments and current findings are described herein.

  2. MOC's Highest Resolution View of Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site] (A) Mars Pathfinder site, left: April 1998; right: January 2000.

    [figure removed for brevity, see original site] (B) top: April 1998; bottom: January 2000.

    Can Mars Global Surveyor's 1.5 meter (5 ft) per pixel camera be used to find any evidence as to the fate of the Mars Polar Lander that was lost on December 3, 1999? One way to find out is to look for one of the other Mars landers and determine what, if anything, can be seen. There have been three successful Mars lander missions: Viking 1 (July 1976), Viking 2 (September 1976), and Mars Pathfinder (July 1997). Of these, the location of Mars Pathfinder is known the best because there are several distinct landmarks visible in the lander's images that help in locating the spacecraft. The MGS MOC Operations Team at Malin Space Science Systems has been tasked since mid-December 1999 with looking for the lost Polar Lander. Part of this effort has been to test the capabilities of MOC by taking a picture of the landing site of Mars Pathfinder.

    An attempt to photograph the Pathfinder site was made once before, in April 1998, by turning the entire MGS spacecraft so that the camera could point at the known location of the Mars Pathfinder lander. Turning the MGS spacecraft like this is not a normal operation--it takes considerable planning, and disrupts the on-going, normal acquisition of science data. It took 3 attempts to succeed, but on April 22, 1998, MOC acquired the picture seen on the left side of Figure A, above. The three near-by major landmarks that were visible to the Pathfinder's cameras are labeled here (North Peak, Big Crater, Twin Peaks). It was known at the time that this image was not adequate to see the Pathfinder lander because the camera was not in focus and had a resolution of only 3.3 meters (11 ft) per pixel. In this and all other images shown here, north is up. All views of the 1998 MOC image are illuminated from the lower right, all views

  3. MARS PATHFINDER LANDER REMOVED FROM SHIPPING CONTAINER IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the SAEF-2 spacecraft checkout facility at Kennedy Space Center, engineers and technicians from Jet Propulsion Laboratory remove the Mars Pathfinder lander from its shipping container, still covered in protective wrapping. Pictured from L-R, Linda Robeck, Jerry Gutierrez, Lorraine Garcia, Chuck Foehlinger of JPL. The arrival of the spacecraft at KSC from Pasadena, CA occurred on Aug. 13, 1996. Launch of Mars Pathfinder aboard a McDonnell Douglas Delta II rocket will occur from Pad B at Complex 17 on Dec. 2.

  4. Atmosphere structure and meteorology instrument for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Seiff, Alvin

    1994-01-01

    The MESUR Science Definition Team recommended that all MESUR probes, including Pathfinder, carry an ASI/MET experiment, in order that no opportunity be lost to characterize the atmosphere of Mars in passing through it. The experiment was thus included on Pathfinder from the start (February 1992), but on an essentially noninterference basis: It was to make no unusual demands on the spacecraft. A Science Advisory Team was appointed by NASA Headquarters in September 1993 first met on November 3rd to initiate formal science participation, and the level of activity has since been high. The instrument passed its Preliminary Design Review on February 28th.

  5. PATHFINDER: Probing Atmospheric Flows in an Integrated and Distributed Environment

    NASA Technical Reports Server (NTRS)

    Wilhelmson, R. B.; Wojtowicz, D. P.; Shaw, C.; Hagedorn, J.; Koch, S.

    1995-01-01

    PATHFINDER is a software effort to create a flexible, modular, collaborative, and distributed environment for studying atmospheric, astrophysical, and other fluid flows in the evolving networked metacomputer environment of the 1990s. It uses existing software, such as HDF (Hierarchical Data Format), DTM (Data Transfer Mechanism), GEMPAK (General Meteorological Package), AVS, SGI Explorer, and Inventor to provide the researcher with the ability to harness the latest in desktop to teraflop computing. Software modules developed during the project are available in the public domain via anonymous FTP from the National Center for Supercomputing Applications (NCSA). The address is ftp.ncsa.uiuc.edu, and the directory is /SGI/PATHFINDER.

  6. LISA Pathfinder and eLISA news

    NASA Technical Reports Server (NTRS)

    Thorpe, James Ira; Mueller, Guido

    2014-01-01

    Two important gatherings of the space-based gravitational-wave detector community were held in Zurich, Switzerland this past March. The first was a meeting of the Science Working Team for LISA Pathfinder (LPF), a dedicated technology demonstrator mission for a future LISA-like gravitational wave observatory. LPF is entering an extremely exciting phase with launch less than 15 months away. All flight components for both the European science payload, known as the LISA Technology Package (LTP), and the NASA science payload, known as the Space Technology 7 Disturbance Reduction System (ST7-DRS), have been delivered and are undergoing integration. The final flight component for the spacecraft bus, a cold-gas thruster based on the successful GAIA design, will be delivered later this year. Current focus is on completing integration of the science payload (see Figures 1 and 2) and preparation for operations and data analysis. After a launch in Summer 2015, LPF will take approximately 90 days to reach its operational orbit around the Earth-Sun Lagrange point (L1), where it will begin science operations. After 90 days of LTP operations followed by 90 days of DRS operations, LPF will have completed its prime mission of paving the way for a space-based observatory of gravitational waves in the milliHertz band. Immediately following the meeting of the LPF team, the eLISA consortium held its third progress meeting. The consortium (www.elisascience.org) is the organizing body of the European space-based gravitational-wave community, and it was responsible for the "The Gravitational Universe" whitepaper that resulted in the November 2013 election of a gravitational-wave science theme for ESA's Cosmic Visions L3 opportunity. In preparation for an L3 mission concept call, which is expected later this decade, and for launch in the mid 2030s, the eLISA consortium members are coordinating technology development and mission study activities which will build on the LPF results. The final

  7. New protection initiatives announced for coral reefs

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Off the coasts of some of the South Pacific's most idyllic-sounding atolls, Austin Bowden-Kerby has seen first-hand the heavy damage to coral reefs from dynamite and cyanide fishing. For instance, while snorkeling near Chuuk, an island in Micronesia, he has observed craters and rubble beds of coral, which locals have told him date to World War II ordnance.A marine biologist and project scientist for the Coral Gardens Initiative of the Foundation for the Peoples of the South Pacific, Bowden-Kerby has also identified what he says are some public health effects related to destroyed coral reefs and their dying fisheries. These problems include protein and vitamin A deficiency and blindness, all of which may—in some instances—be linked to poor nutrition resulting from lower reef fish consumption by islanders, according to Bowden-Kerby.

  8. Re-examination of Mars Pathfinder parachute drag coefficient estimate

    NASA Technical Reports Server (NTRS)

    Desai, P.; Schofield, T.; Lisano, M.

    2003-01-01

    The Mars Exploration Rover (MER) mission utilizes the Mars Pathfinder (MPF) parachute design. The MPF parachute drag coefficient is a driver for the MER entry, descent, and landing (EDL) design. As a result, a good estimate of the performance of the MPF parachute at Mars is required.

  9. Teacher Job Satisfaction: Lessons from the TSW Pathfinder Project

    ERIC Educational Resources Information Center

    Butt, Graham; Lance, Ann; Fielding, Antony; Gunter, Helen; Rayner, Steve; Thomas, Hywel

    2005-01-01

    Government policy assumes that modernization and remodelling will be effective as external intervention mechanisms to improve job satisfaction. Based on data collected as part of the evaluation of the "Transforming the School Workforce Pathfinder Project", an argument is presented here which suggests that internal management models may be more…

  10. A Pathfinder for Animal Research and Animal Rights.

    ERIC Educational Resources Information Center

    Anderson, David C.

    1992-01-01

    This pathfinder was originally prepared for "Biomedical Research and Animal Rights," a session sponsored by the Veterinary Medical Libraries and Research Libraries Sections of the Medical Library Association. Current resources are described, from bibliographies to electronic bulletin boards, which relate to the issue of laboratory animal welfare…

  11. Pathfinders for Four Directions: An Indigenous Educational Model.

    ERIC Educational Resources Information Center

    Roy, Loriene, Comp.

    The Four Directions Project, administered by the Pueblo of Laguna Department of Education, is a 5-year federally-funded technology innovation grant that aims to help Native people and their educators develop culturally relevant curricula through technology. This report includes the full text of 45 "pathfinders" designed by students in the Graduate…

  12. Sedimentary geomorphology of the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Rice, James W., Jr.; Parker, Timothy Jay

    1997-01-01

    The first landing on Mars in over 20 years will take place July 4, 1997, near te mouth of the Ares Vallis outflow channel located in southeastern Chryse Planitia. Mars Pathfinder, unlike Viking 1, is expected to land on a surface that has a distinct and unambiguous fluvial signature.

  13. Relating MBSE to Spacecraft Development: A NASA Pathfinder

    NASA Technical Reports Server (NTRS)

    Othon, Bill

    2016-01-01

    The NASA Engineering and Safety Center (NESC) has sponsored a Pathfinder Study to investigate how Model Based Systems Engineering (MBSE) and Model Based Engineering (MBE) techniques can be applied by NASA spacecraft development projects. The objectives of this Pathfinder Study included analyzing both the products of the modeling activity, as well as the process and tool chain through which the spacecraft design activities are executed. Several aspects of MBSE methodology and process were explored. Adoption and consistent use of the MBSE methodology within an existing development environment can be difficult. The Pathfinder Team evaluated the possibility that an "MBSE Template" could be developed as both a teaching tool as well as a baseline from which future NASA projects could leverage. Elements of this template include spacecraft system component libraries, data dictionaries and ontology specifications, as well as software services that do work on the models themselves. The Pathfinder Study also evaluated the tool chain aspects of development. Two chains were considered: 1. The Development tool chain, through which SysML model development was performed and controlled, and 2. The Analysis tool chain, through which both static and dynamic system analysis is performed. Of particular interest was the ability to exchange data between SysML and other engineering tools such as CAD and Dynamic Simulation tools. For this study, the team selected a Mars Lander vehicle as the element to be designed. The paper will discuss what system models were developed, how data was captured and exchanged, and what analyses were conducted.

  14. Modis, SeaWIFS, and Pathfinder funded activities

    NASA Technical Reports Server (NTRS)

    Evans, Robert H.

    1995-01-01

    MODIS (Moderate Resolution Imaging Spectrometer), SeaWIFS (Sea-viewing Wide Field Sensor), Pathfinder, and DSP (Digital Signal Processor) objectives are summarized. An overview of current progress is given for the automatic processing database, client/server status, matchup database, and DSP support.

  15. Results of the Imager for Mars Pathfinder Windsock Experiment

    NASA Technical Reports Server (NTRS)

    Sullivan, R.; Golombek, M.; Greeley, R.; Herkenhoff, K.; Kraft, M.; Murphy, J.; Smith, P.; Wilson, G.

    2000-01-01

    The IMP windsock experiment measured wind speeds at three heights within 1.2 m of the martian surface during Pathfinder landed operations. Data from the strongest breezes indicate aerodynamic roughness = 3 cm, wind friction speeds up to 1 m/sec.

  16. Australia's Great Barrier Reef

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Great Barrier Reef extends for 2,000 kilometers along the northeastern coast of Australia. It is not a single reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was acquired by the MISR instrument on August 26, 2000 (Terra orbit 3679), and shows part of the southern portion of the reef adjacent to the central Queensland coast. The width of the MISR swath is approximately 380 kilometers, with the reef clearly visible up to approximately 200 kilometers from the coast. It may be difficult to see the myriad details in the browse image, but if you retrieve the higher resolution version, a zoomed display reveals the spectacular structure of the many reefs.

    The more northerly coastal area in this image shows the vast extent of sugar cane cultivation, this being the largest sugar producing area in Australia, centered on the city of Mackay. Other industries in the area include coal, cattle, dairying, timber, grain, seafood, and fruit. The large island off the most northerly part of the coast visible in this image is Whitsunday Island, with smaller islands and reefs extending southeast, parallel to the coast. These include some of the better known resort islands such as Hayman, Lindeman, Hamilton, and Brampton Islands.

    Further south, just inland of the small semicircular bay near the right of the image, is Rockhampton, the largest city along the central Queensland coast, and the regional center for much of central Queensland. Rockhampton is just north of the Tropic of Capricorn. Its hinterland is a rich pastoral, agricultural, and mining region.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  17. Coral Reef Ecosystems

    NASA Astrophysics Data System (ADS)

    Yap, Helen T.

    Coral reefs are geological structures of significant dimensions, constructed over millions of years by calcifying organisms. The present day reef-builders are hard corals belonging to the order Scleractinia, phylum Cnidaria. The greatest concentrations of coral reefs are in the tropics, with highest levels of biodiversity situated in reefs of the Indo-West Pacific region. These ecosystems have provided coastal protection and livelihood to human populations over the millennia. Human activities have caused destruction of these habitats, the intensity of which has increased alarmingly since the latter decades of the twentieth century. The severity of this impact is directly related to exponential growth rates of human populations especially in the coastal areas of the developing world. However, a more recently recognized phenomenon concerns disturbances brought about by the changing climate, manifested mainly as rising sea surface temperatures, and increasing acidification of ocean waters due to greater drawdown of higher concentrations of atmospheric carbon dioxide. Management efforts have so far not kept pace with the rates of degradation, so that the spatial extent of damaged reefs and the incidences of localized extinction of reef species are increasing year after year. The major management efforts to date consist of establishing marine protected areas and promoting the active restoration of coral habitats.

  18. Results of the Imager for Mars Pathfinder windsock experiment

    USGS Publications Warehouse

    Sullivan, R.; Greeley, R.; Kraft, M.; Wilson, G.; Golombek, M.; Herkenhoff, K.; Murphy, J.; Smith, P.

    2000-01-01

    The Imager for Mars Pathfinder (IMP) windsock experiment measured wind speeds at three heights within 1.2 m of the Martian surface during Pathfinder landed operations. These wind data allowed direct measurement of near-surface wind profiles on Mars for the first time, including determination of aerodynamic roughness length and wind friction speeds. Winds were light during periods of windsock imaging, but data from the strongest breezes indicate aerodynamic roughness length of 3 cm at the landing site, with wind friction speeds reaching 1 m/s. Maximum wind friction speeds were about half of the threshold-of-motion friction speeds predicted for loose, fine-grained materials on smooth Martian terrain and about one third of the threshold-of-motion friction speeds predicted for the same size particles over terrain with aerodynamic roughness of 3 cm. Consistent with this, and suggesting that low wind speeds prevailed when the windsock array was not imaged and/or no particles were available for aeolian transport, no wind-related changes to the surface during mission operations have been recognized. The aerodynamic roughness length reported here implies that proposed deflation of fine particles around the landing site, or activation of duneforms seen by IMP and Sojourner, would require wind speeds >28 m/s at the Pathfinder top windsock height (or >31 m/s at the equivalent Viking wind sensor height of 1.6 m) and wind speeds >45 m/s above 10 m. These wind speeds would cause rock abrasion if a supply of durable particles were available for saltation. Previous analyses indicate that the Pathfinder landing site probably is rockier and rougher than many other plains units on Mars, so aerodynamic roughness length elsewhere probably is less than the 3-cm value reported for the Pathfinder site. Copyright 2000 by the American Geophysical Union.

  19. An overview of Miocene reefs

    SciTech Connect

    Jordan, C.F. Jr. ); Colgan, M.W. ); Frost, S.H. ); Glenn, E.C. ); Bosence, D. ); Esteban, M. )

    1990-05-01

    Miocene reefs lived approximately within the latitudes of 27{degree}S to 48{degree}N compared with 25{degree}S and 32{degree}N for Holocene reefs. This expansion of reef-growing environments was the result of warm Miocene climates, aided by a eustatic sea level rise and tectonic styles that provided numerous foundations for reef development. The majority of Miocene reefs are found in three main areas: (1) Southeast Asia and the western Pacific, (2) the Mediterranean-Middle East, and (3) Middle America and the Caribbean. These regions, with their distinctive suites of coral and foramineral species, formed three biological provinces; respectively, they are the Indo-Pacific, Tethyan, and Western Atlantic provinces. Miocene reefs in Southeast Asia occur in several foreland basins as patch reef complexes on paleohighs and as barrier reefs in back-arc basins. Those reefs in the Mediterranean occur as fringing reefs, middle-shelf patch reefs, or as barrier reefs on the edges of tectonic blocks associated with Alpine thrust belts. Most reefs in the Caribbean grew on isolated open-ocean highs of volcanic origin. Miocene reefs display a diversity of framework types: (1) coral-encrusting, red algal boundstones with diverse coral faunas, (2) branching coral-encrusting, red algal boundstones with a limited Poritid fauna, (3) encrusting red algal boundstones. Barrier reef systems are especially rich in encrusting red algae and robust corals; grainstones are common as interbedded sediment. Patch reef complexes, however, display muddy carbonate textures, may have less diverse coral faunas, and commonly have larger foraminifera. The global distribution of Miocene reefs is important because (1) it provides insight into a paleoclimatic view of the earth during a major greenhouse stage and (2) Miocene buildups, such as the Arun (EUR of 14 tcf) and Bima fields (EUR of about 100 MMBO), are exploration targets.

  20. Coral reefs: Turning back time

    NASA Astrophysics Data System (ADS)

    Lough, Janice M.

    2016-03-01

    An in situ experiment finds that reducing the acidity of the seawater surrounding a natural coral reef significantly increases reef calcification, suggesting that ocean acidification may already be slowing coral growth. See Letter p.362

  1. Analyzing the Effects of Climate Change on Sea Surface Temperature in Monitoring Coral Reef Health in the Florida Keys Using Sea Surface Temperature Data

    NASA Technical Reports Server (NTRS)

    Jones, Jason; Burbank, Renane; Billiot, Amanda; Schultz, Logan

    2011-01-01

    This presentation discusses use of 4 kilometer satellite-based sea surface temperature (SST) data to monitor and assess coral reef areas of the Florida Keys. There are growing concerns about the impacts of climate change on coral reef systems throughout the world. Satellite remote sensing technology is being used for monitoring coral reef areas with the goal of understanding the climatic and oceanic changes that can lead to coral bleaching events. Elevated SST is a well-documented cause of coral bleaching events. Some coral monitoring studies have used 50 km data from the Advanced Very High Resolution Radiometer (AVHRR) to study the relationships of sea surface temperature anomalies to bleaching events. In partnership with NOAA's Office of National Marine Sanctuaries and the University of South Florida's Institute for Marine Remote Sensing, this project utilized higher resolution SST data from the Terra's Moderate Resolution Imaging Spectroradiometer (MODIS) and AVHRR. SST data for 2000-2010 was employed to compute sea surface temperature anomalies within the study area. The 4 km SST anomaly products enabled visualization of SST levels for known coral bleaching events from 2000-2010.

  2. Impact Of Coral Structures On Wave Directional Spreading Across A Shallow Reef Flat - Lizard Island, Northern Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Leon, J. X.; Baldock, T.; Callaghan, D. P.; Hoegh-guldberg, O.; Mumby, P.; Phinn, S. R.; Roelfsema, C. M.; Saunders, M. I.

    2013-12-01

    global-scale degradation in coral reef health is causing a lowering of reef carbonate production that might lead to a decrease in reef structure and roughness.

  3. Coral reef hydrogeology

    SciTech Connect

    Buddemeier, R.W.; Oberdorfer, J.A.

    1985-05-21

    Knowledge of internal flow velocities and pore water residence time is important in understanding pore water geochemistry, nutrient fluxes at the benthic boundary, reef diagenesis, and fresh water resources in reef islands. Hydrogeologic studies of Pacific and Indian Ocean reef and atoll islands indicate a dual aquifer systems; the major Pleistocene aquifer has hydraulic conductivities on the order of 1000 m/d, while the overlying Holocene aquifer of unconsolidated sediments is at least an order of magnitude less permeable. The high permeability in the Pleistocene formation is the result of large voids, both constructional and from subaerial solution during low stands of the sea. Wind, wave and tide induced head differences ranging from a few centimeters to several tens of centimeters provide the driving force for internal flow. Pore water residence times and geochemistry will vary greatly, depending on whether the water is in a major flow channel or in more restricted pores. Studies of both submerged reefs and atoll islands give bulk pore water residence times on the order of months to a few years. Chemical analyses of pore water indicate that both carbonate solution and precipitation are taking place, which will alter porosity and permeability with time. The dual aquifer model also suggests that the Ghyben-Herzberg lens approach to reef island fresh water resources is inaccurate and can lead to a gross overestimation of the potable resource. 18 refs., 5 figs.

  4. Reefs at risk.

    PubMed

    Hinrichsen, D

    1999-01-01

    Coral reefs, considered the rainforests of the seas, are home to a diverse number of marine species. These reefs are tightly woven ecosystems with complex linkages, which, if disturbed, result in an unpleasant chain of events. Furthermore, these reefs are the main source of animal protein for more than a billion people. Aside from supplying food, they stabilize shorelines and protect the land from rising seas and storm damage. Also, they provide sources of medicines used for bone grafts and treatment for certain viruses. However, these reefs are in danger of being permanently damaged as a result of natural and man-made forces. In response to this threat, most marine scientists have suggested that local communities be involved in the implementation and management of programs, with the aim of achieving sustainable reef maintenance. In addition, international agencies have taken the initiative to finance such programs to ensure their continuity. Overall, the management and development of coastal ecosystems depend on how they are managed and not on how they are being exploited. Resources must be rebuilt and their protection ensured for future generations. PMID:12322541

  5. Mars Pathfinder First Anniversary Special -- Refined Landing Site Location

    NASA Technical Reports Server (NTRS)

    1998-01-01

    It has been one year since NASA's Return to the Red Planet began with the spectacular landing of Mars Pathfinder and its microrover, Sojourner. The spacecraft bounced onto a flood-washed landscape on July 4, 1997.

    Mars Pathfinder was soon joined by the orbiting Mars Global Surveyor on September 11, 1997 (PDT). Mars Global Surveyor's high resolution camera, MOC, took a picture of the Mars Pathfinder landing site region during its 256th orbit on April 22, 1998. This picture--at about 5 meters (11 feet) per pixel--is the best available for the site. The previous best images were from the Viking 1 Orbiter in 1976, and had resolutions of about 38 meters (125 feet) per pixel.

    The MOC image has allowed scientists to determine the exact location of the Mars Pathfinder lander. Unfortunately, the image resolution is not good enough to actually see the lander--nor can any of the familiar boulders (e.g., 'Yogi') be seen at this resolution.

    Using the MOC image, the landing site location has been refined by Dr. Michael Malin, Principal Investigator for the Mars Global Surveyor MOC Team and a Participating Scientist on the Mars Pathfinder mission. The images above illustrate how the landing site was located by using the 'sight lines' published by T. Parker (Jet Propulsion Laboratory, Pasadena, CA) and topographic map provided by R. Kirk (U.S. Geological Survey, Flagstaff, AZ).

    Left image: MOC image 25603 subframe, shown at 15 meters (about 50 feet) per pixel resolution. Small, colored box is a topographic map of the Mars Pathfinder landing site produced by the U.S. Geological Survey (Flagstaff, AZ) from Mars Pathfinder stereographic images . Dark, heavy lines are 'sight lines' to various landmarks seen along the horizon in Mars Pathfinder camera images, measured by T. Parker and matched to features seen in Viking Orbiter images. These lines were published in Science, v. 278, p. 1746, December 5, 1997. The lighter, thinner sightlines are the same lines, adjusted to

  6. First light of the LINC-NIRVANA Pathfinder experiment

    NASA Astrophysics Data System (ADS)

    Bergomi, M.; Viotto, V.; Arcidiacono, C.; Marafatto, L.; Farinato, J.; Baumeister, H.; Bertram, T.; Berwein, J.; Briegel, F.; Conrad, A.; Kittman, F.; Kopon, D.; Hofferbert, R.; Magrin, D.; Radhakrishnan Santhakumari, K. K.; Puglisi, A.; Xompero, M.; Briguglio, R.; Quiros-Pacheco, F.; Herbst, T. M.; Ragazzoni, R.

    2014-07-01

    The LINC-NIRVANA Pathfinder experiment is a test-bed to verify a very complex sub-system: the Ground-layer Wavefront Sensor, or GWS. Pathfinder will test the GWS in its final working environment and demonstrate on-sky the performance achievable with a multiple natural guide star, ground-layer adaptive optics system with a very wide FoV. The GWS uses up to 12 natural guide stars within a 2.8'-6' annular field of view and drives the LBT adaptive secondary mirror to correct the lower layers of atmospheric turbulence. This paper will trace the path of the instrument on its way to First Light on-sky in November 2013, from its installation on the telescope to the calibrations to its final operation, focusing in particular on opto-mechanical and software aspects and how they lead to the main achieved results.

  7. The LISA Pathfinder Mission. Tracing Einstein's Geodesics in Space

    NASA Astrophysics Data System (ADS)

    Racca, Giuseppe D.; McNamara, Paul W.

    2010-03-01

    LISA Pathfinder, formerly known as SMART-2, is the second of the European Space Agency’s Small Missions for Advance Research and Technology, and is designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission, by testing the core assumption of gravitational wave detection and general relativity: that free particles follow geodesics. The new technologies to be demonstrated in a space environment include: inertial sensors, high precision laser interferometry to free floating mirrors, and micro-Newton proportional thrusters. LISA Pathfinder will be launched on a dedicated launch vehicle in late 2011 into a low Earth orbit. By a transfer trajectory, the sciencecraft will enter its final orbit around the first Sun-Earth Lagrange point. First science results are expected approximately 3 months thereafter. Here, we give an overview of the mission including the technologies being demonstrated.

  8. Interface Generation and Compositional Verification in JavaPathfinder

    NASA Technical Reports Server (NTRS)

    Giannakopoulou, Dimitra; Pasareanu, Corina

    2009-01-01

    We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.

  9. True Color of Mars - Pathfinder Sol 39 Sunrise

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sunrise, sol 39. This true color, pre-sunrise image (approximately 0530LST) is composed of six images extending 30 o in azimuth and 45 o in elevation and shows the brownish gray predawn sky. A description of the techniques used to generate this color image from IMP data can be found in Maki et al., 1999. Note: a calibrated output device is required accurately reproduce the correct colors.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal investigator.

  10. LISA Pathfinder: picometers and femtoNewtons in space

    NASA Astrophysics Data System (ADS)

    Hewitson, Martin; LISA Pathfinder Team Team

    2016-03-01

    On December 3rd at 04:04 UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space. This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.

  11. Postglacial fringing-reef to barrier-reef conversion on Tahiti links Darwin's reef types.

    PubMed

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C; Braithwaite, Colin; Kennedy, David M; Spencer, Tom; Webster, Jody M; Woodroffe, Colin D

    2014-01-01

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy. PMID:24845540

  12. Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types

    NASA Astrophysics Data System (ADS)

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

    2014-05-01

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy.

  13. Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types

    PubMed Central

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

    2014-01-01

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy. PMID:24845540

  14. 2005 PathfinderPlus Aero-Elastic Research Flight

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2005-01-01

    This viewgraph presentation describes the 2005 Pathfinder along with an investigation of its aeroelastic responses. The contents include: 1) HALE Class of Vehicles; 2) Aero-elastic Research Flights Overall Objective; 3) General Arrangement; 4) Sensor Locations; 5) NASA Ramp Operations; 6) Lakebed Operations; 7) 1st Flight Data Set; 8) Tool development / data usage; 9) HALE Tool Development & Validation; 10) Building a HALE Foundation; 11) Compelling Needs Drive HALE Efforts; and 12) Team Photo

  15. Java PathFinder: A Translator From Java to Promela

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus

    1999-01-01

    JAVA PATHFINDER, JPF, is a prototype translator from JAVA to PROMELA, the modeling language of the SPIN model checker. JPF is a product of a major effort by the Automated Software Engineering group at NASA Ames to make model checking technology part of the software process. Experience has shown that severe bugs can be found in final code using this technique, and that automated translation from a programming language to a modeling language like PROMELA can help reducing the effort required.

  16. ST7-DRS on LISA Pathfinder: Initial Status

    NASA Astrophysics Data System (ADS)

    Cutler, Curt; Ziemer, John; Barela, Phil; Demmons, Nathaniel; Dunn, Charles; Hruby, Vlad; Hsu, Oscar; Liepack, Otfrid; Maghami, Peiman; O'Donnell, James; Slutsky, Jacob; Thorpe, James; Romero-Wolfe, Andrew

    2016-03-01

    LISA Pathfinder (LPF), a European Space Agency Mission to demonstrate technologies for future space-based gravitational wave observatories, was launched from French Guiana on Dec 3, 2015. A payload on LPF is the NASA-provided ST7 Disturbance Reduction System (ST7-DRS). We will describe the current state of ST7-DRS, including results from the initial on-orbit commissioning and the experimental plan for the ST7-DRS operations in the summer of 2016.

  17. Grid resolution and solution convergence for Mars Pathfinder forebody

    NASA Technical Reports Server (NTRS)

    Nettelhorst, Heather L.; Mitcheltree, Robert A.

    1994-01-01

    As part of the Discovery Program, NASA Plans to launch a series of probes to Mars. The Mars Pathfinder project is the first of this series with a scheduled Mars arrival in July 1997. The entry vehicle will perform a direct entry into the atmosphere and deliver a lander to the surface. Predicting the entry vehicle's flight performance and designing the forebody heatshield requires knowledge of the expected aerothermodynamic environment. Much of this knowledge can be obtained through computational fluid dynamic (CFD) analysis.

  18. Goldstone radar contributions to Mars Pathfinder landing safety

    NASA Technical Reports Server (NTRS)

    Slade, Martin A.; Jurgens, R. F.

    1994-01-01

    Goldstar radar can provide topography 'profiles', statistical surface roughness, and radar images within a few degrees of the sub-Earth point. Goldstone/Very Large Array (VLA) bistatic radar observations can image the whole disk of Mars with integration times on the order of ten min before pixel smearing occurs. Data from all these radar techniques can be useful for observing the local surface conditions relating to landing safety issues for Mars Pathfinder.

  19. Feedbacks Between Wave Energy And Declining Coral Reef Structure: Implications For Coastal Morphodynamics

    NASA Astrophysics Data System (ADS)

    Grady, A. E.; Jenkins, C. J.; Moore, L. J.; Potts, D. C.; Burgess, P. M.; Storlazzi, C. D.; Elias, E.; Reidenbach, M. A.

    2013-12-01

    The incident wave energy dissipated by the structural complexity and bottom roughness of coral reef ecosystems, and the carbonate sediment produced by framework-building corals, provide natural shoreline protection and nourishment, respectively. Globally, coral reef ecosystems are in decline as a result of ocean warming and acidification, which is exacerbated by chronic regional stressors such as pollution and disease. As a consequence of declining reef health, many reef ecosystems are experiencing reduced coral cover and shifts to dominance by macroalgae, resulting in a loss of rugosity and thus hydrodynamic roughness. As coral reef architecture is compromised and carbonate skeletons are eroded, wave energy dissipation and sediment transport patterns--along with the carbonate sediment budget of the coastal environment--may be altered. Using a Delft3D numerical model of the south-central Molokai, Hawaii, fringing reef, we simulate the effects of changing reef states on wave energy and sediment transport. To determine the temporally-varying effects of biotic and abiotic stressors such as storms and bleaching on the reef structure and carbonate production, we couple Delft3D with CarboLOT, a model that simulates growth and competition of carbonate-producing organisms. CarboLOT is driven by the Lotka-Volterra population ecology equations and niche suitability principles, and accesses the CarboKB database for region-specific, carbonate-producing species information on growth rates, reproduction patterns, habitat suitability, as well as organism geometries. Simulations assess how changing reef states--which alter carbonate sediment production and reef morphology and thus hydrodynamic roughness--impact wave attenuation and sediment transport gradients along reef-fronted beaches. Initial results suggest that along fringing reefs having characteristics similar to the Molokai fringing reef, projected sea level rise will likely outpace coral reef accretion, and the increased

  20. Characterization of the LISA Pathfinder Drag Reduction System

    NASA Astrophysics Data System (ADS)

    Slutsky, Jacob; LISA Pathfinder Team

    2015-04-01

    The LISA Pathfinder mission will be launched this year by ESA, and so it is urgent to simulate and characterize key experiments to optimize and validate the Gravitational Reference Sensor (GRS) performance. Success of this technology directly applies to any future LISA-like mission. Pathfinder is comprised of both European and NASA payloads, the LISA Technology Package (LTP) and Space Technology 7 (ST-7), respectively. ST-7 includes a Colloid Micro-Newton Thruster (CMNT) system, to maneuver the spacecraft with low noise, and a control system for spacecraft and test mass actuation. European partners have developed the LTP Data Analysis (LTPDA) Matlab suite, including state-space simulations of the full mission to create mock data, analysis pipelines constructed to reduce this and eventual actual data. We have adapted this infrastructure to reflect CMNT physics and control design where they differ from LTP. We analyze the residual GRS acceleration noise, paying particular attention to ST-7 specific CMNT noise characterization experiments and the performance differentials between using the inertial and interferometric sensing systems of Pathfinder in and out of loop. I will discuss our current results analyzing simulated ST-7 experimental runs and our future plans.

  1. LISA and LISA Pathfinder: Gravitational Wave Observation in Space

    NASA Technical Reports Server (NTRS)

    Guzman, Felipe

    2010-01-01

    The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1 mHz--100 mHz. This observation band is inaccessible to ground-based detectors due to fluctuations in the Earth gravitational field. Gravitational wave sources for LISA include galactic binaries, mergers of supermassive black-hole binaries, extreme-mass-ratio inspirals, and cosmology backgrounds and bursts. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset of 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such as spacecraft control with micronewton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. A detailed description of the two missions and an overview of current investigations conducted by the community will be discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented.

  2. Latest Results from the Mars Pathfinder Atmospheric Structure Investigation

    NASA Technical Reports Server (NTRS)

    Magalhaes, J. A.

    1999-01-01

    The Mars Pathfinder Atmospheric Structure Investigation (ASI) obtained information on Martian atmospheric structure from three science accelerometers, which measured the deceleration of the probe at all levels in the atmosphere. Entry, descent, and landing occurred within 850 km of the Viking 1 landing site and somewhat later in northern summer. Pathfinder entered at 3 AME Local Mars Time (LMT), which provided the first opportunity to study Mars' nighttime atmospheric structure, and Viking 1 entered at 4:15 PME LMT. Magalhaes et al and Schofield et al have previously reported on the analysis of accelerometer measurements from the entry phase, which ended at about 8.5 km. The derived temperature profile extends from 140 km altitude down to 8.9 km, with a vertical resolution ranging from 250 meters to 50 meters, respectively. Here we report on a refined analysis of the Pathfinder entry phase ASIE data in which the effects of the small angular motions of the entry vehicle have been removed, thus enabling a search for small amplitude and small vertical wavelength structures. In addition, we will report on the atmospheric structure at altitudes below 8 km which is being derived from the accelerometer data acquired during the parachute descent phase. Additional information is contained in the original extended abstract.

  3. Drosophila multiplexin (Dmp) modulates motor axon pathfinding accuracy.

    PubMed

    Meyer, Frauke; Moussian, Bernard

    2009-06-01

    Multiplexins are multidomain collagens typically composed of an N-terminal thrombospondin-related domain, an interrupted triple helix and a C-terminal endostatin domain. They feature a clear regulatory function in the development of different tissues, which is chiefly conveyed by the endostatin domain. This domain can be found in proteolytically released monomeric and trimeric versions, and their diverse and opposed effects on the migratory behavior of epithelial and endothelial cell types have been demonstrated in cell culture experiments. The only Drosophila multiplexin displays specific features of both vertebrate multiplexins, collagens XV and XVIII. We characterized the Drosophila multiplexin (dmp) gene and found that three main isoforms are expressed from it, one of which is the monomeric endostatin version. Generation of dmp deletion alleles revealed that Dmp plays a role in motor axon pathfinding, as the mutants exhibit ventral bypass defects of the intersegmental nerve b (ISNb) similar to other motor axon guidance mutants. Transgenic overexpression of monomeric endostatin as well as of full-length Dmp, but not trimeric endostatin, were able to rescue these defects. In contrast, trimeric endostatin increased axon pathfinding accuracy in wild type background. We conclude that Dmp plays a modulating role in motor axon pathfinding and may be part of a buffering system that functions to avoid innervation errors. PMID:19469789

  4. Matrix interactions modulate neurotrophin-mediated neurite outgrowth and pathfinding

    PubMed Central

    Madl, Christopher M.; Heilshorn, Sarah C.

    2015-01-01

    Both matrix biochemistry and neurotrophic factors are known to modulate neurite outgrowth and pathfinding; however, the interplay between these two factors is less studied. While previous work has shown that the biochemical identity of the matrix can alter the outgrowth of neurites in response to neurotrophins, the importance of the concentration of cell-adhesive ligands is unknown. Using engineered elastin-like protein matrices, we recently demonstrated a synergistic effect between matrix-bound cell-adhesive ligand density and soluble nerve growth factor treatment on neurite outgrowth from dorsal root ganglia. This synergism was mediated by Schwann cell-neurite contact through L1CAM. Cell-adhesive ligand density was also shown to alter the pathfinding behavior of dorsal root ganglion neurites in response to a gradient of nerve growth factor. While more cell-adhesive matrices promoted neurite outgrowth, less cell-adhesive matrices promoted more faithful neurite pathfinding. These studies emphasize the importance of considering both matrix biochemistry and neurotrophic factors when designing biomaterials for peripheral nerve regeneration. PMID:26170800

  5. True Color of Mars - Pathfinder Sol 10 at noon

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The true color of Mars based upon three filters with the sky set to aluminance of 60. The color of the Pathfinder landing site is yellowish brown with only subtle variations. These colors are identical to the measured colors of the Viking landing sites reported by Huck et al. [1977]. This image was taken near local noon on Sol 10. A description of the techniques used to generate this color image from IMP data can be found in Maki et al., 1999. Note: a calibrated output device is required accurately reproduce the correct colors.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  6. Coral reef resilience through biodiversity

    USGS Publications Warehouse

    Rogers, Caroline S.

    2013-01-01

    Irrefutable evidence of coral reef degradation worldwide and increasing pressure from rising seawater temperatures and ocean acidification associated with climate change have led to a focus on reef resilience and a call to “manage” coral reefs for resilience. Ideally, global action to reduce emission of carbon dioxide and other greenhouse gases will be accompanied by local action. Effective management requires reduction of local stressors, identification of the characteristics of resilient reefs, and design of marine protected area networks that include potentially resilient reefs. Future research is needed on how stressors interact, on how climate change will affect corals, fish, and other reef organisms as well as overall biodiversity, and on basic ecological processes such as connectivity. Not all reef species and reefs will respond similarly to local and global stressors. Because reef-building corals and other organisms have some potential to adapt to environmental changes, coral reefs will likely persist in spite of the unprecedented combination of stressors currently affecting them. The biodiversity of coral reefs is the basis for their remarkable beauty and for the benefits they provide to society. The extraordinary complexity of these ecosystems makes it both more difficult to predict their future and more likely they will have a future.

  7. The evolution of reef communities

    SciTech Connect

    Fagerstrom, J.A.

    1987-01-01

    This book discusses the composition, structure, occurrence, and changes in reefs during the past 2 billion years. It emphasizes the functional roles of major groups (guilds) of reef-building, reef-destroying, and reed-dwelling organisms in the most complex of all marine communities. A structural model, based on modern reef guilds, is developed. Then the functional roles of each major reef-building higher biologic taxon (algae, sponges, coral, etc.) is determined, and, on this basis, each such taxon is assigned to a reef community guild. Next, the authors traces the geologic history and guild assignment of each major taxon through geologic time. The final chapter establishes a succession of ten major reef community types, and considers their extinction and recovery in the light of modern theories of cosmic and earthly events.

  8. CORAL REEF BIOCRITERIA

    EPA Science Inventory

    Coral reefs worldwide are experiencing the greatest decline of their known existence and few tools are available to offset the growing impacts of human coastal and watershed activities. Biocriteria are a potentially effective means to evaluate and restore impaired waters, but are...

  9. Coral Reef Biological Criteria

    EPA Science Inventory

    Coral reefs worldwide are experiencing decline from a variety of stressors. Some important stressors are land-based sources of pollution and human activities in the coastal zone. However, few tools are available to offset the impact of these stressors. The Clean Water Act (CWA...

  10. Tradeoffs between fisheries harvest and the resilience of coral reefs.

    PubMed

    Bozec, Yves-Marie; O'Farrell, Shay; Bruggemann, J Henrich; Luckhurst, Brian E; Mumby, Peter J

    2016-04-19

    Many countries are legally obliged to embrace ecosystem-based approaches to fisheries management. Reductions in bycatch and physical habitat damage are now commonplace, but mitigating more sophisticated impacts associated with the ecological functions of target fisheries species are in their infancy. Here we model the impacts of a parrotfish fishery on the future state and resilience of Caribbean coral reefs, enabling us to view the tradeoff between harvest and ecosystem health. We find that the implementation of a simple and enforceable size restriction of >30 cm provides a win:win outcome in the short term, delivering both ecological and fisheries benefits and leading to increased yield and greater coral recovery rate for a given harvest rate. However, maintaining resilient coral reefs even until 2030 requires the addition of harvest limitations (<10% of virgin fishable biomass) to cope with a changing climate and induced coral disturbances, even in reefs that are relatively healthy today. Managing parrotfish is not a panacea for protecting coral reefs but can play a role in sustaining the health of reefs and high-quality habitat for reef fisheries. PMID:27044106

  11. Coral records of reef-water pH across the central Great Barrier Reef, Australia: assessing the influence of river runoff on inshore reefs

    NASA Astrophysics Data System (ADS)

    D'Olivo, J. P.; McCulloch, M. T.; Eggins, S. M.; Trotter, J.

    2014-07-01

    The boron isotopic (δ11Bcarb) compositions of long-lived Porites coral are used to reconstruct reef-water pH across the central Great Barrier Reef (GBR) and assess the impact of river runoff on inshore reefs. For the period from 1940 to 2009, corals from both inner as well as mid-shelf sites exhibit the same overall decrease in δ11Bcarb of 0.086 ± 0.033‰ per decade, equivalent to a~decline in seawater pH (pHsw) of ~ 0.017 ± 0.007 pH units per decade. This decline is consistent with the long-term effects of ocean acidification based on estimates of CO2 uptake by surface waters due to rising atmospheric levels. We also find that compared to the mid-shelf corals, the δ11Bcarb compositions for inner shelf corals subject to river discharge events, have higher and more variable values and hence higher inferred pHsw values. These higher δ11Bcarb values for inner-shelf corals are particularly evident during wet years, despite river waters having lower pH. The main effect of river discharge on reef-water carbonate chemistry thus appears to be from higher nutrients driving increased phytoplankton productivity, resulting in the drawdown of pCO2 and increase in pHsw. Increased primary production therefore has the potential to counter the more transient effects of low pH river water (pHrw) discharged into near-shore environments. Importantly however, inshore reefs also show a consistent pattern of sharply declining coral growth that coincides with periods of high river discharge. This occurs despite these reefs having higher pHsw values and hence higher seawater aragonite saturation states, demonstrating the over-riding importance of local reef-water quality on coral reef health.

  12. Coral records of reef-water pH across the central Great Barrier Reef, Australia: assessing the influence of river runoff on inshore reefs

    NASA Astrophysics Data System (ADS)

    D'Olivo, J. P.; McCulloch, M. T.; Eggins, S. M.; Trotter, J.

    2015-02-01

    The boron isotopic (δ11Bcarb) compositions of long-lived Porites coral are used to reconstruct reef-water pH across the central Great Barrier Reef (GBR) and assess the impact of river runoff on inshore reefs. For the period from 1940 to 2009, corals from both inner- and mid-shelf sites exhibit the same overall decrease in δ11Bcarb of 0.086 ± 0.033‰ per decade, equivalent to a decline in seawater pH (pHsw) of ~0.017 ± 0.007 pH units per decade. This decline is consistent with the long-term effects of ocean acidification based on estimates of CO2 uptake by surface waters due to rising atmospheric levels. We also find that, compared to the mid-shelf corals, the δ11Bcarb compositions of inner-shelf corals subject to river discharge events have higher and more variable values, and hence higher inferred pHsw values. These higher δ11Bcarb values of inner-shelf corals are particularly evident during wet years, despite river waters having lower pH. The main effect of river discharge on reef-water carbonate chemistry thus appears to be from reduced aragonite saturation state and higher nutrients driving increased phytoplankton productivity, resulting in the drawdown of pCO2 and increase in pHsw. Increased primary production therefore has the potential to counter the more transient effects of low-pH river water (pHrw) discharged into near-shore environments. Importantly, however, inshore reefs also show a consistent pattern of sharply declining coral growth that coincides with periods of high river discharge. This occurs despite these reefs having higher pHsw, demonstrating the overriding importance of local reef-water quality and reduced aragonite saturation state on coral reef health.

  13. Rapid survey protocol that provides dynamic information on reef condition to managers of the Great Barrier Reef.

    PubMed

    Beeden, R J; Turner, M A; Dryden, J; Merida, F; Goudkamp, K; Malone, C; Marshall, P A; Birtles, A; Maynard, J A

    2014-12-01

    Managing to support coral reef resilience as the climate changes requires strategic and responsive actions that reduce anthropogenic stress. Managers can only target and tailor these actions if they regularly receive information on system condition and impact severity. In large coral reef areas like the Great Barrier Reef Marine Park (GBRMP), acquiring condition and impact data with good spatial and temporal coverage requires using a large network of observers. Here, we describe the result of ~10 years of evolving and refining participatory monitoring programs used in the GBR that have rangers, tourism operators and members of the public as observers. Participants complete Reef Health and Impact Surveys (RHIS) using a protocol that meets coral reef managers' needs for up-to-date information on the following: benthic community composition, reef condition and impacts including coral diseases, damage, predation and the presence of rubbish. Training programs ensure that the information gathered is sufficiently precise to inform management decisions. Participants regularly report because the demands of the survey methodology have been matched to their time availability. Undertaking the RHIS protocol we describe involves three ~20 min surveys at each site. Participants enter data into an online data management system that can create reports for managers and participants within minutes of data being submitted. Since 2009, 211 participants have completed a total of more than 10,415 surveys at more than 625 different reefs. The two-way exchange of information between managers and participants increases the capacity to manage reefs adaptively, meets education and outreach objectives and can increase stewardship. The general approach used and the survey methodology are both sufficiently adaptable to be used in all reef regions. PMID:25179944

  14. Pattern and intensity of human impact on coral reefs depend on depth along the reef profile and on the descriptor adopted

    NASA Astrophysics Data System (ADS)

    Nepote, Ettore; Bianchi, Carlo Nike; Chiantore, Mariachiara; Morri, Carla; Montefalcone, Monica

    2016-09-01

    Coral reefs are threatened by multiple global and local disturbances. The Maldives, already heavily hit by the 1998 mass bleaching event, are currently affected also by growing tourism and coastal development that may add to global impacts. Most of the studies investigating effects of local disturbances on coral reefs assessed the response of communities along a horizontal distance from the impact source. This study investigated the status of a Maldivian coral reef around an island where an international touristic airport has been recently (2009-2011) built, at different depths along the reef profile (5-20 m depth) and considering the change in the percentage of cover of five different non-taxonomic descriptors assessed through underwater visual surveys: hard corals, soft corals, other invertebrates, macroalgae and abiotic attributes. Eight reefs in areas not affected by any coastal development were used as controls and showed a reduction of hard coral cover and an increase of abiotic attributes (i.e. sand, rock, coral rubble) at the impacted reef. However, hard coral cover, the most widely used descriptor of coral reef health, was not sufficient on its own to detect subtle indirect effects that occurred down the reef profile. Selecting an array of descriptors and considering different depths, where corals may find a refuge from climate impacts, could guide the efforts of minimising local human pressures on coral reefs.

  15. Miocene reefs in western Mediterranean

    SciTech Connect

    Esteban, M.

    1988-01-01

    Coral reefs were particularly abundant and well developed during the late Tortonian and Messinian in southeastern Spain, the Balearic Islands, Italy, Sicily, Algeria, and Morocco. These reefs occurred just before and during the deposition of the thick Messinian evaporite units in the basinal areas and disappeared completely from Mediteranean during the early Pliocene. Most of the coral reefs are fringing terrigenous coastal fan complexes with very small lagoons and show progradation of less than 2 km. Some of the reefs occur on, or are intercalated with, Neogene volcanics or Messinian evaporites. Barrier-reef complexes are less common, have extensive lagoons behind them, and show complex progradational geometries more than 10 km wide. Excellent outcrops allow detailed reconstruction of paleogeography and sea level changes. Progradation predominated during phases of relative sea level drops and stillsands, while significant retrogradation occurred during sea level rises. The coral reef wall framework is commonly less than 20 m thick and is dominated by Porites and, locally, Tarbellastrae. Older Miocene reefs are less well developed, but show greater diversity of corals and reef organisms. Younger Miocene reef complexes occurring in open ocean settings are formed by only one branching coral genus (Porites or, locally, Tarbellastraea) with branching colonies up to 7 m high. Halimeda sands are particularly abundant in the upper reef slopes with occasional intercalations of red algae pavements that most likely coincide with episodes of terrigenous influx.

  16. The Barrier Reef sediment apron: Tobacco Reef, Belize

    NASA Astrophysics Data System (ADS)

    MacIntyre, Ian G.; Graus, Richard R.; Reinthal, Peter N.; Littler, Mark M.; Littler, Diane S.

    1987-07-01

    Sedimentological and biological surveys of the back-reef sediment apron of Tobacco Reef, a continuous segment of the Belizean Barrier Reef, reveal five distinct biogeological zones: (1) coralline-coral- Dictyota pavement, (2) Turbinaria-Sargassum rubble, (3) Laurencia-Acanthophora sand and gravel, (4) bare sand and 95 Thalassia sand. These zones parallel the entire 9-km reef. The distribution of these zones is related to the spatial patterns of fish herbivory, the size of bottom sediments, and the stability of the substrate. Sedimentological and hydrodynamic studies indicate that most of the sediments in this area are transported from the reef crest and fore reef during periods of storm or hurricane activity and that their size distribution is largely the result of differential transport by high bottom-water velocities during those periods.

  17. NOAA Coral Reef Watch: Decision Support Tools for Coral Reef Managers

    NASA Astrophysics Data System (ADS)

    Rauenzahn, J.; Eakin, C.; Skirving, W. J.; Burgess, T.; Christensen, T.; Heron, S. F.; Li, J.; Liu, G.; Morgan, J.; Nim, C.; Parker, B. A.; Strong, A. E.

    2010-12-01

    A multitude of natural and anthropogenic stressors exert substantial influence on coral reef ecosystems and contribute to bleaching events, slower coral growth, infectious disease outbreaks, and mortality. Satellite-based observations can monitor, at a global scale, environmental conditions that influence both short-term and long-term coral reef ecosystem health. From research to operations, NOAA Coral Reef Watch (CRW) incorporates paleoclimatic, in situ, and satellite-based biogeophysical data to provide near-real-time and forecast information and tools to help managers, researchers, and other stakeholders interpret coral health and stress. CRW has developed an operational, near-real-time product suite that includes sea surface temperature (SST), SST time series data, SST anomaly charts, coral bleaching HotSpots, and Degree Heating Weeks (DHW). Bi-weekly global SST analyses are based on operational nighttime-only SST at 50-km resolution. CRW is working to develop high-resolution products to better address thermal stress on finer scales and is applying climate models to develop seasonal outlooks of coral bleaching. Automated Satellite Bleaching Alerts (SBAs), available at Virtual Stations worldwide, provide the only global early-warning system to notify managers of changing reef environmental conditions. Currently, CRW is collaborating with numerous domestic and international partners to develop new tools to address ocean acidification, infectious diseases of corals, combining light and temperature to detect coral photosystem stress, and other parameters.

  18. Reef Fishes of Saba Bank, Netherlands Antilles: Assemblage Structure across a Gradient of Habitat Types

    PubMed Central

    Toller, Wes; Debrot, Adolphe O.; Vermeij, Mark J. A.; Hoetjes, Paul C.

    2010-01-01

    Saba Bank is a 2,200 km2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km2 area of the bank for an exploratory study. Habitat and reef fish assemblages were investigated in five shallow-water benthic habitat types that form a gradient from Saba Bank shelf edge to lagoon. Significant coral cover was restricted to fore reef habitat (average cover 11.5%) and outer reef flat habitat (2.4%) and declined to near zero in habitats of the central lagoon zone. Macroalgae dominated benthic cover in all habitats (average cover: 32.5 – 48.1%) but dominant algal genera differed among habitats. A total of 97 fish species were recorded. The composition of Saba Bank fish assemblages differed among habitat types. Highest fish density and diversity occurred in the outer reef flat, fore reef and inner reef flat habitats. Biomass estimates for commercially valued species in the reef zone (fore reef and reef flat habitats) ranged between 52 and 83 g/m2. The composition of Saba Bank fish assemblages reflects the absence of important nursery habitats, as well as the effects of past fishing. The relatively high abundance of large predatory fish (i.e. groupers and sharks), which is generally considered an indicator of good ecosystem health for tropical reef systems, shows that an intact trophic network is still present on Saba Bank. PMID:20502637

  19. Ecological intereactions of reef building corals

    EPA Science Inventory

    Coral reefs are very important marine ecosystems because they support tremendous biodiversity and reefs are critical economic resources many coastal nations. Tropical reef structures are largely built by stony corals. This presentation provides background on basic coral biology t...

  20. An observational heat budget analysis of a coral reef, Heron Reef, Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    MacKellar, Mellissa C.; McGowan, Hamish A.; Phinn, Stuart R.

    2013-03-01

    Measurements of the surface energy balance, the structure and evolution of the convective atmospheric reef layer (CARL), and local meteorology and hydrodynamics were made during June 2009 and February 2010 at Heron Reef, Australia, to establish the relative partitioning of heating within the water and atmosphere. Horizontal advection was shown to moderate temperature in the CARL and the water, having a cooling influence on the atmosphere, and providing an additional source or sink of energy to the water overlying the reef, depending on tide. The key driver of atmospheric heating was surface sensible heat flux, while heating of the reef water was primarily due to solar radiation, and thermal conduction and convection from the reef substrate. Heating and cooling processes were more defined during winter due to higher sensible and latent heat fluxes and strong diurnal evolution of the CARL. Sudden increases in water temperature were associated with inundation of warmer oceanic water during the flood tide, particularly in winter due to enhanced nocturnal cooling of water overlying the reef. Similarly, cooling of the water over the reef occurred during the ebb tide as heat was transported off the reef to the surrounding ocean. While these results are the first to shed light on the heat budget of a coral reef and overlying CARL, longer-term, systematic measurements of reef thermal budgets are needed under a range of meteorological and hydrodynamic conditions, and across various reef types to elucidate the influence on larger-scale oceanic and atmospheric processes. This is essential for understanding the role of coral reefs in tropical and sub-tropical meteorology; the physical processes that take place during coral bleaching events, and coral and algal community dynamics on coral reefs.

  1. Neural pathfinding on uni- and multidirectional photopolymerized micropatterns.

    PubMed

    Tuft, Bradley W; Xu, Linjing; White, Scott P; Seline, Alison E; Erwood, Andrew M; Hansen, Marlan R; Guymon, C Allan

    2014-07-23

    Overcoming signal resolution barriers of neural prostheses, such as the commercially available cochlear impant (CI) or the developing retinal implant, will likely require spatial control of regenerative neural elements. To rationally design materials that direct nerve growth, it is first necessary to determine pathfinding behavior of de novo neurite growth from prosthesis-relevant cells such as spiral ganglion neurons (SGNs) in the inner ear. Accordingly, in this work, repeating 90° turns were fabricated as multidirectional micropatterns to determine SGN neurite turning capability and pathfinding. Unidirectional micropatterns and unpatterned substrates are used as comparisons. Spiral ganglion Schwann cell alignment (SGSC) is also examined on each surface type. Micropatterns are fabricated using the spatial reaction control inherent to photopolymerization with photomasks that have either parallel line spacing gratings for unidirectional patterns or repeating 90° angle steps for multidirectional patterns. Feature depth is controlled by modulating UV exposure time by shuttering the light source at given time increments. Substrate topography is characterized by white light interferometry and scanning electron microscopy (SEM). Both pattern types exhibit features that are 25 μm in width and 7.4 ± 0.7 μm in depth. SGN neurites orient randomly on unpatterned photopolymer controls, align and consistently track unidirectional patterns, and are substantially influenced by, but do not consistently track, multidirectional turning cues. Neurite lengths are 20% shorter on multidirectional substrates compared to unidirectional patterns while neurite branching and microfeature crossing events are significantly higher. For both pattern types, the majority of the neurite length is located in depressed surface features. Developing methods to understand neural pathfinding and to guide de novo neurite growth to specific stimulatory elements will enable design of innovative

  2. Laser Interferometry for Gravitational Wave Observation: LISA and LISA Pathfinder

    NASA Technical Reports Server (NTRS)

    Guzman, Felipe

    2010-01-01

    The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1mHz-100mHz. This observation band is inaccessible to ground-based detectors due to the large ground motions of the Earth. Gravitational wave sources for LISA include galactic binaries, mergers of supermasive black-hole binaries, extreme-mass-ratio inspirals, and possibly from as yet unimagined sources. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset oF 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such us spacecraft control with micro-newton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. An introduction to laser interferometric gravitational wave detection, ground-based observatories, and a detailed description of the two missions together with an overview of current investigations conducted by the community will bc discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented

  3. NASA Ocean Altimeter Pathfinder Project. Report 1; Data Processing Handbook

    NASA Technical Reports Server (NTRS)

    Koblinsky, C. J.; Beckley, Brian D.; Ray, Richard D.; Wang, Yan-Ming; Tsaoussi, Lucia; Brenner, Anita; Williamson, Ron

    1998-01-01

    The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-sedes data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. This report describes the processing schemes used to produce a consistent data set and two of the products derived f rom these data. Other reports have been produced that: a) describe the validation of these data sets against tide gauge measurements and b) evaluate the statistical properties of the data that are relevant to climate change. The use of satellite altimetry for earth observations was proposed in the early 1960s. The first successful space based radar altimeter experiment was flown on SkyLab in 1974. The first successful satellite radar altimeter was flown aboard the Geos-3 spacecraft between 1975 and 1978. While a useful data set was collected from this mission for geophysical studies, the noise in the radar measured and incomplete global coverage precluded ft from inclusion in the Ocean Altimeter Pathfinder program. This program initiated its analysis with the Seasat mission, which was the first satellite radar altimeter flown for oceanography.

  4. Neural Pathfinding on Uni- and Multidirectional Photopolymerized Micropatterns

    PubMed Central

    2015-01-01

    Overcoming signal resolution barriers of neural prostheses, such as the commercially available cochlear impant (CI) or the developing retinal implant, will likely require spatial control of regenerative neural elements. To rationally design materials that direct nerve growth, it is first necessary to determine pathfinding behavior of de novo neurite growth from prosthesis-relevant cells such as spiral ganglion neurons (SGNs) in the inner ear. Accordingly, in this work, repeating 90° turns were fabricated as multidirectional micropatterns to determine SGN neurite turning capability and pathfinding. Unidirectional micropatterns and unpatterned substrates are used as comparisons. Spiral ganglion Schwann cell alignment (SGSC) is also examined on each surface type. Micropatterns are fabricated using the spatial reaction control inherent to photopolymerization with photomasks that have either parallel line spacing gratings for unidirectional patterns or repeating 90° angle steps for multidirectional patterns. Feature depth is controlled by modulating UV exposure time by shuttering the light source at given time increments. Substrate topography is characterized by white light interferometry and scanning electron microscopy (SEM). Both pattern types exhibit features that are 25 μm in width and 7.4 ± 0.7 μm in depth. SGN neurites orient randomly on unpatterned photopolymer controls, align and consistently track unidirectional patterns, and are substantially influenced by, but do not consistently track, multidirectional turning cues. Neurite lengths are 20% shorter on multidirectional substrates compared to unidirectional patterns while neurite branching and microfeature crossing events are significantly higher. For both pattern types, the majority of the neurite length is located in depressed surface features. Developing methods to understand neural pathfinding and to guide de novo neurite growth to specific stimulatory elements will enable design of innovative

  5. The Data Processor of the JEM-EUSO pathfinders

    NASA Astrophysics Data System (ADS)

    Scotti, V.; Osteria, G.

    2014-06-01

    JEM-EUSO is a wide-angle refractive UV telescope being proposed for attachment to the Japanese Experiment Module on ISS. The main goal of the mission is to study Extreme Energy Cosmic Rays. Two pathfinder mission are now in progress: EUSO-TA and EUSO-Balloon. The EUSO-TA project foresees the installation of a telescope prototype in the Telescope Array site. The aim of this project is to calibrate the telescope with the TA fluorescence detector. An initial run of one year starting from 2013 is foreseen. EUSO-Balloon is a pathfinder mission in which a prototype telescope will be mounted on a stratospheric balloon. The main aim of this mission is to perform a end-to-end test of all the key technologies and instrumentation of JEM-EUSO detectors and to prove the global detection chain. EUSO-Balloon will measure the UV background fundamental for the development of the simulations. EUSO-Balloon has the potential to detect Extensive Air Showers from above, paving the way for any future space-based EECR observatory. We will present the Data Processor of the pathfinders. The DP is the component of the Electronics System which performs data management and instrument control. The DP controls front-end electronics, performs 2nd level trigger filtering, tags events with arrival time and payload position through a GPS system, manages mass memory for data storage, measures live and dead time of the telescope, provides signals for time synchronization of the event, performs housekeeping monitor and handles interface to the telemetry system. We will describe the main components of the DP, the state-of-the-art and the results of the tests carried out.

  6. Rock and Soil Types at Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Type areas of rocks and soils. (A) Dark rock type and bright soil type: Shown is the dark rock Barnacle Bill. Reflectance spectra typical of fresh basalt and APXS spectra indicating more silica-rich basaltic andesite compositions characterize this type. These rocks are typically the small boulders and intermediate-sized cobbles at the Pathfinder site. The bright soil type is very common and in this case comprises Barnacle Bill's wind tail and much of the surround soil area. This soil has a high reflectance and a strongly reddened spectrum indicative of oxidized ferric minerals. (B) Bright rock type: Shown is the bright rock Wedge. Reflectance spectra typical of weathered basalt and APXS spectra indicating basaltic compositions characterize this type. These rocks are typically larger than 1 meter in diameter and many display morphologies indicating flood deposition. (C) Pink rock type: Shown is the pink rock Scooby Doo. APXS and reflectance spectra indicate a composition and optical characteristics similar to the drift soil. However, the morphology of the pink rock type indicates a cemented or rocklike structure. This material may be a chemically cemented hardpan that underlies much of the Pathfinder site. (D) Dark soil type: The dark soil type is typically found on the windward sides of rocks or in rock-free areas like Photometry Flats (shown here) where the bright soil has been striped away by aeolian action or in open areas. Other locations include the Mermaid Dune. (E) Disturbed soil type: The darkening of disturbed soil relative to its parent material, bright soil, as a result of changes in soil texture and compaction caused by movement of the rover and retraction of the lander airbag. (F) Lamb-like soil type: This soil type shows reflectance and spectral characteristics intermediate between the bright and dark soils. Its distinguishing feature is a weak spectral absorption near 900 nanometers not seen in either the bright or dark soils.

    NOTE: original

  7. ER-20037 LLNL eternal pathfinder wing spar design study report

    SciTech Connect

    Not Available

    1994-03-01

    This document outlines the results of a design study performed by EDO-FSD on the LLNL Eternal Pathfinder Wing Spar/Fuel Tank. The main focus of the design study was the weight minimization of the composite wall of the mid span spar section of the aircraft. The torque, shear, moment and pressure loading requirements, as well as LLNL`s preliminary drawings, were used to develop a reduced weight mid-span spar design. The design study also encompassed details such as the pressure bulkheads, wing rod connectors, and attachment flanges.

  8. Building Educational Programs for the Australian Square Kilometre Array Pathfinder

    NASA Astrophysics Data System (ADS)

    Hollow, R.; Hobbs, G.

    2010-08-01

    The Australian Square Kilometre Array Pathfinder (ASKAP) will be an array of 36 antennas in Western Australia, each 12-m in diameter, and is due for operation in 2013. With a large instantaneous field-of-view ASKAP will survey the whole sky faster than existing radio telescopes, producing massive data sets. Government funding for ASKAP was contingent on it being available for education purposes, providing an exciting opportunity to develop innovative education projects for schools and citizen science. Building on the PULSE@Parkes program we plan to have a range of activities and resources, providing scope for student investigations. Challenges and educational opportunities are discussed.

  9. Symbolic PathFinder: Symbolic Execution of Java Bytecode

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina S.; Rungta, Neha

    2010-01-01

    Symbolic Pathfinder (SPF) combines symbolic execution with model checking and constraint solving for automated test case generation and error detection in Java programs with unspecified inputs. In this tool, programs are executed on symbolic inputs representing multiple concrete inputs. Values of variables are represented as constraints generated from the analysis of Java bytecode. The constraints are solved using off-the shelf solvers to generate test inputs guaranteed to achieve complex coverage criteria. SPF has been used successfully at NASA, in academia, and in industry.

  10. Missile tracking and range safety: Tracking Interferometer Pathfinder System (TIPS)

    NASA Astrophysics Data System (ADS)

    Dowgiallo, David J.; Rauen, Stephen; Peters, Wendy M.; Polisensky, Emil J.

    2013-05-01

    The tracking of missiles at close range proximity has been an ongoing challenge for many launch environments. The ability to provide accurate missile trajectory information is imperative for range safety and early termination of flight. In an effort to provide a potential solution to tracking issues that have plagued many traditional techniques, the Tracking Interferometer Pathfinder System (TIPS) was developed at the Naval Research Laboratory, Washington, D.C. The paper herein describes the design, field test, and results of an interferometer deployed for missile tracking.