1,098 research outputs found

    The story of Buffalo Bayou and the Houston Ship Channel

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    original book [32] p. : ill., map (fold.) ; 15 x 22 cm

    Rapid Development of Gossamer Propulsion for NASA Inner Solar System Science Missions

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    Over a two and one-half year period dating from 2003 through 2005, NASA s In-Space Propulsion Program matured solar sail technology from laboratory components to full systems, demonstrated in as relevant a space environment as could feasibly be simulated on the ground. This paper describes the challenges identified; as well as the approaches taken toward solving a broad set of issues spanning material science, manufacturing technology, and interplanetary trajectory optimization. Revolutionary advances in system structural predictive analysis and characterization testing occurred. Also addressed are the remaining technology challenges that might be resolved with further ground technology research, geared toward reducing technical risks associated with future space validation and science missions

    Status of Solar Sail Technology Within NASA

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    In the early 2000s, NASA made substantial progress in the development of solar sail propulsion systems for use in robotic science and exploration of the solar system. Two different 20-m solar sail systems were produced and they successfully completed functional vacuum testing in NASA Glenn Research Center's (GRC's) Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L Garde, respectively. The sail systems consist of a central structure with four deployable booms that support the sails. These sail designs are robust enough for deployment in a one-atmosphere, one-gravity environment and were scalable to much larger solar sails perhaps as large as 150 m on a side. Computation modeling and analytical simulations were also performed to assess the scalability of the technology to the large sizes required to implement the first generation of missions using solar sails. Life and space environmental effects testing of sail and component materials were also conducted. NASA terminated funding for solar sails and other advanced space propulsion technologies shortly after these ground demonstrations were completed. In order to capitalize on the $30M investment made in solar sail technology to that point, NASA Marshall Space Flight Center (MSFC) funded the NanoSail-D, a subscale solar sail system designed for possible small spacecraft applications. The NanoSail-D mission flew on board the ill-fated Falcon-1 Rocket launched August 2, 2008, and due to the failure of that rocket, never achieved orbit. The NanoSail-D flight spare will be flown in the Fall of 2010. This paper will summarize NASA's investment in solar sail technology to-date and discuss future opportunitie

    Zero waste to landfill: An unacknowledged supermegaproject

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    Zero Waste is a global movement focused on replacing linear resource-to-waste systems with circular systems found elsewhere in nature, and Zero Waste to Landfill (ZWtL) is a specific interpretation implying the total elimination of residual disposal. Local governments worldwide have declared ZWtL goals with specific deadlines; however, to date none of these initiatives have proven successful. A grounded case study of ZWtL campaigns was conducted to investigate this chronic failure. The results indicate that ZWtL is an unacknowledged supermegaproject: requiring extremely deep and unprecedented change and sacrifice across all sectors, yet destined for failure because proponents fail to recognize the scope of the task and plan accordingly. Strategies for addressing waste upstream are critically absent, with insufficient downstream measures such as recycling the prevailing norm – reinforced by a consistent preference for technical solutions over fundamental behavior change

    TRL Assessment of Solar Sail Technology Development Following the 20-Meter System Ground Demonstrator Hardware Testing

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    The NASA In-Space Propulsion Technology (ISPT) Projects Office has been sponsoring 2 separate, independent system design and development hardware demonstration activities during 2002-2005. ATK Space Systems of Goleta, CA was the prime contractor for one development team and L'Garde, Inc. of Tustin, CA was the prime contractor for the other development team. The goal of these activities was to advance the technology readiness level (TRL) of solar sail propulsion from 3 towards 6 by the year 2006. Component and subsystem fabrication and testing were completed successfully, including the ground deployment of 10-meter and 20-meter ground demonstration hardware systems under vacuum conditions. The deployment and structural testing of the 20-meter solar sail systems was conducted in the 30 meter diameter Space Power Facility thermal-vacuum chamber at NASA Glenn Plum Brook in April though August, 2005. This paper will present the results of the TRL assessment following the solar sail technology development activities associated with the design, development, analysis and testing of the 20-meter system ground demonstrators. Descriptions of the system designs for both the ATK and L'Garde systems will be presented. Changes, additions and evolution of the system designs will be highlighted. A description of the modeling and analyses activities performed by both teams, as well as testing conducted to raise the TRL of solar sail technology will be presented. A summary of the results of model correlation activities will be presented. Finally, technology gaps identified during the assessment and gap closure plans will be presented, along with "lessons learned", subsequent planning activities and validation flight opportunities for solar sail propulsion technology

    Status of Solar Sail Propulsion: Moving Toward an Interstellar Probe

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    NASA's In-Space Propulsion Technology Program has developed the first-generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first-generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an areal density of less than 13 grams-per-square meter. A rigorous, multiyear technology development effort culminated last year in the testing of two different 20-meter solar sail systems under thermal vacuum conditions. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In a separate effort, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long-term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging environments were defined for mission trajectories outside the protection of the earth's magnetosphere, in the solar wind environment. These were used in other analytical tools to prove the adequacy of sail design features for accommodating the harsh space environment. Preceding, and in conjunction with these technology efforts, NASA sponsored several mission application studies for solar sails, including one that would use an evolved sail capability to support humanity's first mission into nearby interstellar space. The proposed mission is called the Interstellar Probe. The Interstellar Probe might be accomplished in several ways. A 200-meter sail, with an areal density approaching 1 gram-per-square meter, could accelerate a robotic probe to the very edge of the solar system in just under 20 years from launch. A sail using the technology just demonstrated could make the same mission, but take significantly longer. Conventional chemical propulsion systems would require even longer flight times. Spinner sails of the type being explored by the Japanese may also be a good option, but the level of maturity in that technology is not clear. While the technology to support a 200-meter, ultralightweight sail mission is not yet in hand, the recent NASA investments in solar sail technology are an essential first step toward making it a reality. This paper will describe the status of solar sail propulsion within NASA, near-term solar sail mission applications, and the plan to advance the technology to the point where the Interstellar Probe mission can be flown

    Mercury Sample Return using Solar Sails

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    A conventional Mercury sample return mission requires significant launch mass due to the large deltav required for the outbound and return trips, and the large mass of a planetary lander and ascent vehicle. Solar sailing can be used to reduce lander mass allocation by delivering the lander to a low, thermally safe orbit close to the terminator. Propellant mass is not an issue for solar sails so a sample can be returned relatively easily, without resorting to lengthy, multiple gravity assists. The initial Mercury sample return studies reported here were conducted under ESA contract ESTEC/16534/02/NL/NR, PI Colin McInnes, Technical Officer Peter Falkner. Updated solar sail capabilities were developed under the Ground System Demonstration program, funded by the NASA's In-Space Propulsion Technology (ISPT) Program

    A broadly applicable method to characterize large DNA viruses and adenoviruses based on the DNA polymerase gene

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    BACKGROUND: Many viral pathogens are poorly characterized, are difficult to culture or reagents are lacking for confirmatory diagnoses. We have developed and tested a robust assay for detecting and characterizing large DNA viruses and adenoviruses. The assay is based on the use of degenerate PCR to target a gene common to these viruses, the DNA polymerase, and sequencing the products. RESULTS: We evaluated our method by applying it to fowl adenovirus isolates, catfish herpesvirus isolates, and largemouth bass ranavirus (iridovirus) from cell culture and lymphocystis disease virus (iridovirus) and avian poxvirus from tissue. All viruses with the exception of avian poxvirus produced the expected product. After optimization of extraction procedures, and after designing and applying an additional primer we were able to produce polymerase gene product from the avian poxvirus genome. The sequence data that we obtained demonstrated the simplicity and potential of the method for routine use in characterizing large DNA viruses. The adenovirus samples were demonstrated to represent 2 types of fowl adenovirus, fowl adenovirus 1 and an uncharacterized avian adenovirus most similar to fowl adenovirus 9. The herpesvirus isolate from blue catfish was shown to be similar to channel catfish virus (Ictalurid herpesvirus 1). The case isolate of largemouth bass ranavirus was shown to exactly match the type specimen and both were similar to tiger frog virus and frog virus 3. The lymphocystis disease virus isolate from largemouth bass was shown to be related but distinct from the two previously characterized lymphocystis disease virus isolates suggesting that it may represent a distinct lymphocystis disease virus species. CONCLUSION: The method developed is rapid and broadly applicable to cell culture isolates and infected tissues. Targeting a specific gene for in the large DNA viruses and adenoviruses provide a common reference for grouping the newly identified viruses according to relatedness to sequences of reference viruses and the submission of the sequence data to GenBank will build the database to make the BLAST analysis a valuable resource readily accessible by most diagnostic laboratories. We demonstrated the utility of this assay on viruses that infect fish and birds. These hosts are phylogenetically distant from mammals yet, sequence data suggests that the assay would work equally as well on mammalian counterparts of these groups of viruses. Furthermore, we demonstrated that obtaining genetic information on routine diagnostic samples has great potential for revealing new virus strains and suggesting the presence of new species
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