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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
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NASA NTRS1986

Geodesy by radio interferometry - Evidence for contemporary plate motion

Analysis of 211 very long baseline interferometry observing sessions carried out between November 1979 and August 1984 has yielded estimates of the distances between various radio telescopes located in North America and Europe. The average rate of change of the distances between four radio telescopes in North America (Haystack Observatory, Massachusetts; Westford Radio Telescope, Massachusetts; George R. Agassiz Station, Texas; and Owens Valley Radio Observatory, California) and one in Europe (Onsala Space Observatory, Sweden) obtained from the analysis of these data is 19 + or 10 mm/yr, where the (68 percent confidence interval) standard deviation is for the estimate of the rate of change of the Haystack-Onsala baseline length, the one determined most accurately from these data. This estimate of the standard deviation is dominated by the effects of correlated systematic errors due mostly to errors in the model used for the atmospheric delay which introduces errors in each baseline length estimate of 40 mm standard deviation and 60 days correlation time. (By contrast the statistical standard deviation is only 2 mm/yr). The estimated geologic rates of change of these baseline lengths, averaged over 10 to the 6th years, are 15 to 17 + or - 3 mm/yr for the various North American sites to Ondala.

Herring, T. A.↗
NASA NTRS1986

A 43GHz VLBI mapping of SiO maser emission associated with Orion-KL IRC-2

A milliarcsecond resolution spot map of the SiO maser emission associated with IRC-2 in Orion-KL is presented. The two dominant groups of spectral features, near V(LRS) = -6 and 16 km/s, were observed in the 43 GHz, v = 1 to 0 transition of SiO, using a Mark III VLBI system. The 74 km baseline ran from Haystack Observatory in Westford, Massachusetts to Five College Radio Astronomy Observatory (FCRAO) in New Salem, Massachusetts. Five distinct maser features were observed: -8.5 to -6.5 km/s; -5 to -1.5 km/s; 12 to 13.5 km/s; 16.5 to 19 km/s; and 20 to 21 km/s (stellar velocity = 5 km/s). The relative positions were established, from an analysis of fringe phases, to an accuracy of about 5 milliarcseconds. All the features lay within an area of radius 0.08 arcseconds or 6x10(14) cm, at a distance of 500 pc. Previous interferometric studies were only able to measure the gross separation between the red and the blue shifted groups. Our measurement of the separation between these two gropus is consistent with those of the previous studies, indicating the persistence of these two centers of activity. The absolute positions of the masers with respect to IRC-2 are only known to an accuracy of about 1 arcsecond. It is assumed that IRC-2 is centered between the red shifted and the blue shifted maser features. The relative placement of these two groups of maser features agrees with observations of thermal emission from SO, which traces the outflow on a much larger scale. The SiO masers trace the neutral outflow from IRC-2 on the smallest scale yet observed.

Greenhill, L. J.↗
NASA NTRS1990

Submillimeter and millimeter observations of solar system objects

Microwave spectroscopy of solar system objects was supported. It necessarily involves millimeter and submillimeter wavelengths where rotational transitions reside. The existing national facilities are at OVRO, the 12-meter at Kitt Peak, UC array at Hat Creek, the Caltech CSO on Mauna Kea, and the 14-meter at the Univ. of Massachusetts, near Amherst. The group used all of these instruments in the last year except the Univ. of Massachusetts 14-meter. This wavelength range (0.3 to 3 mm) is about to enjoy an explosion of interest as submillimeter receivers become better and easier to use. This region of the spectrum is rich in transitions of molecules that exist in the planetary atmospheres which can be studied for temperature-pressure profiles, wind tracers, and atmospheric chemistry. The list of solar system objects that have been recently addressed with these techniques include: (1) Venus: CO studies of T-P profiles, winds, and photochemistry; SO2 detections; Continuum mapping remains to be done at 1 mm; (2) Earth H2O, CO, NO, NO2, O(18)O, etc. as a test bed for other atmospheres; (3) Mars: H2O, CO, O(18)O studies of T-P profiles, winds (fall of 1990), and photochemistry; (4) Saturn: Same as Jupiter plus submillimeter and millimeter mapping of the ring system; (5) Uranus and Neptune: Continuum thermal mapping; and (6) Titan: CO, HCN, and HC3NT-P information and photochemistry. Recent results are given.

Muhleman, Duane O.↗
NASA NTRS1992

Papers presented to the International Colloquium on Venus

This volume contains short papers that have been accepted for the International Colloquium on Venus, August 10-12, Pasadena, California. The Program Committee consisted of Stephen Saunders (Jet Propulsion Laboratory) and Sean C. Solomon (Massachusetts Institute of Technology). Chairmen: Raymond Arvison (Washington University); Vassily Moroz (Institute for Space Research); Donald B. Campbell (Cornell University); Thomas Donahue (University of Michigan); James W. Head III (Brown University); Pamela Jones (Lunar and Planetary Institute); Mona Jasnow, Andrew Morrison, Timothy Pardker, Jeffrey Plaut, Ellen Stofan, Tommy Thompson, Cathy Weitz (Jet Propulsion Laboratory); Gordon Pettengil (Massachusetts Institute of Technology); and Janet Luhmann (University of California, Los Angeles).

Source record↗
NASA NTRS1990

Are highly parallel systems ready for prime time?

This is the edited and abbreviated transcript of a panel discussion held on May 9, 1989, in Los Angeles, during the conference "Parallel Computational Fluid Dynamics-Implementations and Results Using MIMD Computers." The purpose of the conference was to discuss recent developments in the use of MIMD parallel computers in high-performance computational fluid dynamics. The intent of the panel discussion was to summarize the findings of the meeting, and to give a perspective on the state of the art in using parallel computers for solving large-scale engineering and scientific application problems. The panelists were Creon Levit (NAS Systems Division, NASA-Ames Research Center, Moffett Field, California), Kent Misegades (Cray Research, Inc., Mendota Heights, Minnesota), Gary Montry (Myrias Computer Corporation, Albuquerque, New Mexico), Ken Neves (Boeing Computer Services, Seattle, Washington), Anthony Patera (Massachusetts Institute of Technology, Cambridge, Massachusetts), and Justin Rattner (Intel Scientific Computers, Beaverton, Oregon).

Simon, Horst D.↗
NASA NTRS1998

Aeronautics and Aviation Science: Careers and Opportunities Project

The National Aeronautics and Space Administration funded project, Aeronautics and Aviation Science: Careers and Opportunities has been in operation since July, 1995. This project operated as a collaboration with Massachusetts Corporation for Educational Telecommunications, the Federal Aviation Administration, Bridgewater State College and four targeted "core sites" in the greater Boston area. In its first and second years, a video series on aeronautics and aviation science was developed and broadcast via "live, interactive" satellite feed. Accompanying teacher and student supplementary instructional materials for grades 6-9 were produced and disseminated by the Massachusetts Corporation for Educational Telecommunications (MCET). In the MCET grant application it states that project Take Off! in its initial phase would recruit and train teachers at "core" sites in the greater Boston area, as well as opening participation to other on-line users of MCET's satellite feeds. "Core site" classrooms would become equipped so that teachers and students might become engaged in an interactive format which aimed at not only involving the students during the "live" broadcast of the instructional video series, but which would encourage participation in electronic information gathering and sharing among participants. As a Take Off! project goal, four schools with a higher than average proportion of minority and underrepresented youth were invited to become involved with the project to give these students the opportunity to consider career exploration and development in the field of science aviation and aeronautics. The four sites chosen to participate in this project were: East Boston High School, Dorchester High School, Randolph Junior-Senior High School and Malden High School. In year 3 Dorchester was unable to continue to fully participate and exited out. Danvers was added to the "core site" list in year 3. In consideration of Goals 2000, the National Science Foundation standards for quality of teaching, and an educational agenda that promotes high standards for all students, Aeronautics and Aviation Science: Careers and Opportunities had as its aim to deliver products to schools, both in and outside the project sites, which attempt to incorporate multi-disciplined approaches in the presentation of a curriculum which would be appropriate in any classroom, while also aiming to appeal to young women and minorities. The curriculum was developed to provide students with fundamentals of aeronautics and aviation science. The curriculum also encouraged involving students and teachers in research projects, and further information gathering via electronic bulletin boards and internet capabilities. Though not entirely prescriptive, the curriculum was designed to guide teachers through recommended activities to supplement MCET's live telecast video presentations. Classroom teachers were encouraged to invite local pilots, meteorologists, and others from the field of aviation and aeronautics, particularly women and minorities to visit schools and to field questions from the students.

Texter, P. Cardie↗
NASA NTRS1998

Take Off! Aeronautics and Aviation Science: Careers and Opportunities

Funded by National Aeronautic and Space Administration's High Performance Computing and Communications/ Learning Technologies Project (HPCC/LTP) Cooperative Agreement, Aeronautics and aviation Science: Careers and Opportunities was operative from July 1995 through July 1998. This project operated as a collaboration with Massachusetts Corporation for Educational Telecommunications, the Federal Aviation Administration, Bridgewater State College and four targeted "core sites" in the greater Boston area: Dorchester, Malden, East Boston and Randolph. In its first and second years, a video series with a participatory website on aeronautics and aviation science was developed and broadcast via "live, interactive" satellite feed. Accompanying teacher and student supplementary instructional materials for grades 6-12 were produced and disseminated by the Massachusetts Corporation for Educational Telecommunications (MCET). In year three, the project team redesigned the website, edited 14 videos to a five part thematic unit, and developed a teacher's guide to the video and web materials supplement for MAC and PC platforms, aligned with national standards. In the MCET grant application it states that project Take Off! in its initial phase would recruit and train teachers at "core" sites in the greater Boston area, as well as opening participation to other on-line users of MCET's satellite feeds. "Core site" classrooms would become equipped so that teachers and students might become engaged in an interactive format which aimed at not only involving the students during the "live" broadcast of the instructional video series, but which would encourage participation in electronic information gathering and sharing among participants. As a Take Off! project goal, four schools with a higher than average proportion of minority and underrepresented youth were invited to become involved with the project to give these students the opportunity to consider career exploration and development in the field of science aviation and aeronautics. The four sites chosen to participate in this project were East Boston High School, Dorchester High School, Randolph Junior-Senior High School and Malden High School. In year 3 Dorchester was unable to continue to fully participate and exited out. Danvers was added to the "core site" list in year 3.

Source record↗
NASA NTRS2003

The Logical Extension

The same software controlling autonomous and crew-assisted operations for the International Space Station (ISS) is enabling commercial enterprises to integrate and automate manual operations, also known as decision logic, in real time across complex and disparate networked applications, databases, servers, and other devices, all with quantifiable business benefits. Auspice Corporation, of Framingham, Massachusetts, developed the Auspice TLX (The Logical Extension) software platform to effectively mimic the human decision-making process. Auspice TLX automates operations across extended enterprise systems, where any given infrastructure can include thousands of computers, servers, switches, and modems that are connected, and therefore, dependent upon each other. The concept behind the Auspice software spawned from a computer program originally developed in 1981 by Cambridge, Massachusetts-based Draper Laboratory for simulating tasks performed by astronauts aboard the Space Shuttle. At the time, the Space Shuttle Program was dependent upon paper-based procedures for its manned space missions, which typically averaged 2 weeks in duration. As the Shuttle Program progressed, NASA began increasing the length of manned missions in preparation for a more permanent space habitat. Acknowledging the need to relinquish paper-based procedures in favor of an electronic processing format to properly monitor and manage the complexities of these longer missions, NASA realized that Draper's task simulation software could be applied to its vision of year-round space occupancy. In 1992, Draper was awarded a NASA contract to build User Interface Language software to enable autonomous operations of a multitude of functions on Space Station Freedom (the station was redesigned in 1993 and converted into the international venture known today as the ISS)

Source record↗
NASA NTRS2010

Real-Time Teleguidance of a Non-Surgeon Crew Medical Officer Performing Orthopedic Surgery at the Amundsen-Scott South Pole Station During Winter-Over

The Amundsen-Scott South Pole Research station located at the geographic South Pole, is the most isolated, permanently inhabited human outpost on Earth. Medical care is provided to station personnel by a non-surgeon crew medical officer (CMO). During the winter-over period from February to October, the station is isolated, with no incoming or outgoing flights due to severe weather conditions. In late June, four months after the station had closed for the austral winter, a 31 year old meteorologist suffered a complete rupture of his patellar tendon while sliding done an embankment. An evacuation was deemed to be too risky to aircrews due to the extreme cold and darkness. A panel of physicians from Massachusetts General Hospital, Johns Hopkins University and the University of Texas Medical Branch were able to assess the patient remotely via telemedicine and agreed that surgery was the only means to restore mobility and prevent long term disability. The lack of a surgical facility and a trained surgical team were overcome by conversion of the clinic treatment area, and intensive preparation of medical laypersons as surgical assistants. The non-surgeon CMO and CMO assistant at South Pole, were guided through the administration of spinal anesthetic, and the two-hour operative repair by medical consultants at Massachusetts General Hospital. Real-time video of the operative field, directions from the remote consultants and audio communication were provided by videoconferencing equipment, operative cameras, and high bandwidth satellite communications. In real-time, opening incision/exposure, tendon relocation, hemostatsis, and operative closure by the CMO was closely monitored and guided and by the remote consultants. The patient s subsequent physical rehabilitation over the ensuing months of isolation was also monitored remotely via telemedicine. This was the first time in South Pole s history that remote teleguidance had been used for surgery and represents a model for real-time guidance of CMO s working at remote duty stations.

Otto, Christian↗
NASA NTRS2010

Aerogels Insulate Against Extreme Temperatures

In 1992, NASA started to pursue the development of aerogel for cryogenic insulation. Kennedy Space Center awarded Small Business Innovation Research (SBIR) contracts to Aspen Systems Inc., of Marlborough, Massachusetts, that resulted in a new manufacturing process and a new flexible, durable, easy-to-use form of aerogel. Aspen Systems formed Aspen Aerogels Inc., in Northborough, Massachusetts, to market the product, and by 2009, the company had become the leading provider of aerogel in the United States, producing nearly 20 million square feet per year. With an array of commercial applications, the NASA-derived aerogel has most recently been applied to protect and insulate people s hands and feet.

Source record↗
NASA NTRS2013

Rovers Pave the Way for Hospital Robots

The Jet Propulsion Laboratory provided funding for the Massachusetts Institute of Technology to develop capabilities for robotics like Rocky 7. After developing the operating system, Daniel Theobald started working at Cambridge, Massachusetts-based Vecna Technologies. Today, Vecna's QC Bot incorporates systems based on the NASA work and is being used to ease logistics at hospitals. The technology has contributed to 20 new jobs.

Source record↗
NASA NTRS2017

LCRD Update and Path to Optical Relay Operations

Speaker and Presenter at the Lincoln Laboratory Communications Workshop on May 23, 2017 at the Massachusetts Institute of Technology Lincoln Laboratory in Lexington, MA. This presentation discusses a concept for an evolution of NASAs optical communications near-Earth relay architecture. NASA's Laser Communications Relay Demonstration (LCRD) is a joint project between NASAs Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT LL). LCRD will provide a minimum of two years of high data rate optical communications service experiments in geosynchronous orbit (GEO) following launch in 2019. This presentation will provide an update of the LCRD mission status and planned capabilities and experiments, followed by a discussion of the path from LCRD to operational network capabilities.

Space Communications↗
NASA NTRS2020

Charles River Watershed Water Resources: Assessing Flooding Vulnerability to Assist High Water Intervention and Urban Planning Programs in the Charles River Watershed

The Charles River watershed intersects 35 municipalities within the Boston Metropolitan Area and has a population of 1.2 million, making it one of the most densely populated watersheds in New England. In recent years, the watershed has observed higher rates of flood inundation, mainly due to increased development, extreme precipitation events, and increased surface runoff. As the frequency of flood events increases and a changing climate poses an ongoing threat to local communities, governments, and organizations in Massachusetts need accurate flood risk assessments. This project partnered with the Charles River Watershed Association, the Town of Natick’s Office of Sustainability, and the Massachusetts Audubon Society to assess the potential for watershed degradation, flood vulnerability, and flood susceptibility in the watershed. The team used Landsat 5 Thematic Mapper (TM), Landsat 8 Operational Land Imager (OLI), Sentinel-1 C-Band Synthetic Aperture Radar (C-SAR), and Sentinel-2 MultiSpectral Instrument (MSI) to assess the feasibility of identifying flood events using remote sensing. After identifying images that overlapped with the reported flood events, the team concluded that it was not feasible to use Earth observation data to detect localized flooding. Instead, the Federal Emergency Management Agency (FEMA) 100-year floodplain was used as a proxy for areas where flooding may occur. The team used statistical analysis and supervised classification to develop a flood susceptibility map, incorporating factors like soil drainage, height above nearest drainage, and topographic wetness index. This was overlaid with demographic and socioeconomic data to create a flood vulnerability map. The flood susceptibility map captured over 2/3 of reported flood events in the watershed, an improvement over the 1/3 of events captured by the FEMA 100-year and 500-year floodplain maps.

DEVELOP Project Summary↗
NASA NTRSDate not supplied

Assessing Flooding Vulnerability to Assist High Water Intervention and Urban Planning Programs in the Charles River Watershed with NASA DEVELOP

The Charles River watershed intersects 35 municipalities within the Boston Metropolitan Area and has a total population of 1.2 million, making it one of the most densely populated watersheds in New England. In recent years, the watershed has observed higher rates of flood inundation, mainly due to increased development, extreme precipitation events, and increased surface runoff. As the frequency of flooding events increases and a changing climate poses an ongoing threat to local communities, governments and organizations in Massachusetts are in need of accurate flood risk assessments. NASA DEVELOP partnered with the Charles River Watershed Association, the Town of Natick’s Office of Sustainability, and the Massachusetts Audubon Society to assess flood vulnerability and susceptibility in the watershed. The team used Landsat 5 Thematic Mapper, Landsat 8 Operational Land Imager, Sentinel-1 C-Band Synthetic Aperture Radar, and Sentinel-2 MultiSpectral Instrument to assess the feasibility of identifying the extent of past flood events using remote sensing. After identifying images that overlapped with reported flood events, the team concluded that it was not feasible to use Earth observation data to detect localized flooding in the time available for this study. Instead, the Federal Emergency Management Agency (FEMA) 100-year floodplain was used as a proxy for areas where flooding may occur. The team used statistical regression analysis and validation and supervised classification to develop a flood susceptibility map, incorporating several flood conditioning factors. The susceptibility maps were calibrated to various thresholds, including two that highlight hypothetical flooding under more liberal and more conservative planning scenarios. These were overlaid with demographic and socioeconomic data to create flood vulnerability maps. The team’s flood susceptibility maps showed an improvement in capturing known flood events over the FEMA 100-year and 500-year floodplain maps. These results will be improved with the addition of stormwater drainage mapping and precipitation data. Results can be used to fill in the gaps to help the stakeholders understand their communities’ vulnerability and susceptibility to flooding and improve their preparedness plans.

Trista Brophy↗
NASA NTRSDate not supplied

Observations of Small Debris from the Cosmos 1408 Anti-Satellite Test using the HUSIR and Goldstone Radars

On 15 November 2021, Russia conducted a direct-ascent, anti-satellite (ASAT) test against its Cosmos 1408 satellite, which had been in orbit since 1982. The test produced at least 1500 fragments trackable by the U.S. Space Surveillance Network (SSN). This is a significant event because the resulting cloud has the potential to endanger the International Space Station and other satellites in low Earth orbit (LEO).For almost 30 years, the NASA Orbital Debris Program Office (ODPO) has been using the Haystack Ultrawideband Imaging Radar (HUSIR), located in Tyngsborough, Massachusetts and operated by the Massachusetts Institute of Technology’s Lincoln Laboratory, to perform statistical measurements of debris in LEO too small to be tracked by the SSN, nominally down to 5.5 mm at 1000 km altitude. The ODPO also utilizes the Goldstone Orbital Debris Radar (Goldstone), located near Barstow, California and operated by the NASA Jet Propulsion Laboratory, to characterize the small debris environment in LEO down to approximately 3 mm at 1000 km altitude. To characterize the small debris component of the Cosmos 1408 ASAT test, a series of observation campaigns were conducted with the HUSIR and Goldstone radars. This paper discusses the observation planning, including beam overlap analysis required for the Goldstone’s bistatic operation, using a model of the debris cloud produced using the NASA Standard Satellite Breakup Model. A description of the radars and the data processing techniques used to analyze the data are also discussed. Finally, results of the measurement campaigns including cumulative flux versus size, altitude, and inclination are presented.

James Murray↗
NASA NTRSDate not supplied

Insights and Observations From Operating A Laser Communication Terminal on the International Space Station (ISS)

The Integrated Laser Communication Relay Demonstration (LCRD) Low Earth Orbit User Modem and Amplifier Terminal (ILLUMA-T) is the first user platform for NASA’s first laser communication relay, LCRD. ILLUMA-T is hosted on the International Space Station (ISS) as an external payload of the Japanese Experiment Module – Exposed Facility (JEM-EF) situated in slot 3. The LCRD payload is hosted on the STPSat-6 spacecraft, which orbits Earth in a geostationary orbit at position 112 W. The ILLUMA-T-to-LCRD system provides a bidirectional, space-to-ground laser communication relay link transferring data up to 1.2 Gbps utilizing two optical ground stations (OGS), OGS-1 in California and OGS-2 in Hawai’i. This paper describes lessons learned from operating the ILLUMA-T system and examines topics such as the end-to-end system availability, predictive versus actual ephemeris, acquisition adjustments, modem timing and handshaking, the terminal’s physical placement and accommodations, and experiment development, execution, and analysis. The authors of this paper operate both the LCRD and ILLUMA-T laser terminals on a daily basis including pass planning, procedure execution, acquisition analysis, and real-time terminal commanding and telemetry monitoring. LCRD is a joint project involving NASA Goddard Space Flight Center (GSFC), the California Institute of Technology Jet Propulsion Laboratory (JPL), and Massachusetts Institute of Technology Lincoln Laboratory (MIT LL). The ILLUMA-T payload is managed by NASA GSFC in Greenbelt, Maryland whose partners include the ISS program office at NASA’s Johnson Space Center (JSC) in Houston, Texas; the Huntsville Operations Support Center (HOSC) at Marshall Space Flight Center (MSFC) in Huntsville, Alabama; the Glenn Research Center (GRC) in Cleveland, Ohio; and the MIT LL in Lexington, Massachusetts. ILLUMA-T is funded by the Space Communications and Navigation (SCaN) Program at NASA Headquarters in Washington, D.C.

Laser Communications↗
NASA NTRS1998

Acronema sippewissettensis Gen. Nov. Sp. Nov., microbial mat bicosoecid (Bicosoecales = Bicosoecida)

A heterotrophic mastigote from the flat laminated Microcoleus-dominated intertidal microbial mat at the Sippewissett salt marsh, Cape Cod, Massachusetts, was isolated into monoprotist culture in the same anoxic medium that led to spirochete and other anaerobic bacterial enrichments. The protist grew vigorously and was transferred indefinitely in oxic marine medium. Videomicroscopy as well as scanning and transmission electron microscopy were used to document its features. The swimming and perching behavior, nutritional mode (bactivory) and morphology including ultra-structure identify it as an aloricate bicosoecid. The presence of heteromorphic acronematic undulipodia, bilateral bipartite tubular mastigonemes, absence of a cytostome, absence of extrusomes, and presence of "Dauerstadien" (duration stages) distinguish this from other Cafeteriaceae bicosoecids. Cell division involves a closed intranuclear spindle. The unspecialized bicosoecid morphology and behavior juxtaposed with oomycete-like vesicles and mastigonemes suggest that this protist may be an extant descendant of a common ancestor of bicosoecids and other stramenopiles (e.g. labyrinthulids, thraustochytrids and oomycetes). A new genus and species, Acronema sippewissettensis, are proposed.

Non-NASA Center↗
NASA NTRS1995

The microbial community of Ophrydium versatile colonies: endosymbionts, residents, and tenants

Ophrydium versatile is a sessile peritrichous ciliate (Kingdom Protoctista, class Oligohymenophora, order Peritrichida, suborder Sessilina) that forms green, gelatinous colonies. Chlorophyll a and b impart a green color to Ophrydium masses due to 400-500 Chlorella-like endosymbionts in each peritrich. Ophrydium colonies, collected from two bog wetlands (Hawley and Leverett, Massachusetts) were analyzed for their gel inhabitants. Other protists include ciliates, mastigotes, euglenids, chlorophytes, and heliozoa. Routine constituents include from 50-100,000 Nitzschia per ml of gel and at least four other diatom genera (Navicula, Pinnularia, Gyrosigma, Cymbella) that may participate in synthesis of the gel matrix. Among the prokaryotes are filamentous and coccoid cyanobacteria, large rod-shaped bacteria, at least three types of spirochetes and one unidentified Saprospira-like organism. Endosymbiotic methanogenic bacteria, observed using fluorescence microscopy, were present in unidentified hypotrichous ciliates. Animals found inside the gel include rotifers, nematodes, and occasional copepods. The latter were observed in the water reservoir of larger Ophrydium masses. From 30-46% of incident visible radiation could be attenuated by Ophrydium green jelly masses in laboratory observations. Protargol staining was used to visualize the elongate macronuclei and small micronucleus of O. versatile zooids and symbiotic algal nuclei. Electron microscopic analysis of the wall of the Chlorella-like symbiont suggests that although the Ophrydium zooids from British Columbia harbor Chlorella vulgaris, those from Hawley Bog contain Graesiella sp. The growth habit in the photic zone and loose level of individuation of macroscopic Ophrydium masses are interpretable as extant analogs of certain Ediacaran biota: colonial protists in the Vendian fossil record.

Non-NASA Center↗