38 Matching Results

Search Results

Advanced search parameters have been applied.

Laser-fusion rocket for interplanetary propulsion

Description: A rocket powered by fusion microexplosions is well suited for quick interplanetary travel. Fusion pellets are sequentially injected into a magnetic thrust chamber. There, focused energy from a fusion Driver is used to implode and ignite them. Upon exploding, the plasma debris expands into the surrounding magnetic field and is redirected by it, producing thrust. This paper discusses the desired features and operation of the fusion pellet, its Driver, and magnetic thrust chamber. A rocket design is presented which uses slightly tritium-enriched deuterium as the fusion fuel, a high temperature KrF laser as the Driver, and a thrust chamber consisting of a single superconducting current loop protected from the pellet by a radiation shield. This rocket can be operated with a power-to-mass ratio of 110 W gm/sup -1/, which permits missions ranging from occasional 9 day VIP service to Mars, to routine 1 year, 1500 ton, Plutonian cargo runs.
Date: September 27, 1983
Creator: Hyde, R.A.
Partner: UNT Libraries Government Documents Department

RYLLA. [X-ray transport code]

Description: This paper describes a computer code, RYLLA, which models the deposition of x-rays into thin metal slabs, and transports the resulting photoelectrons, finding the distribution of electrons leaving the slab from both the front and back surfaces. The slab must be homogeneous, but can contain a mixture of up to 5 different elements. Due to the short electron mean free path at low electron energies, RYLLA should be used only for studying thin slabs, roughly < 100 mg/cm/sup 2/ for low Z metals, and < 10 mg/cm/sup 2/ for high Z metals. X-ray energies should be in the range of 1 to 150 keV, as they are deposited only via photoionization and Compton scattering processes. Following photoionization, a hole exists in the electron cloud of the absorbing atom. This fills either by Auger or fluoresence, resulting in lower energy holes which are also filled. Fluoresence photons are transported and absorbed in the same manner as the primary photons, except that they are isotropically produced. Once all photons have been transported and absorbed, and all holes have been filled, a space- and energy-dependent electron source spectrum has been obtained. This is used in a discrete ordinate expansion solution of the 1-D transport equation, which gives the output electron spectra at the two slab surfaces. This paper discusses both the physics and coding of RYLLA. Examples of user input are given, as are some comparisons with other codes.
Date: June 8, 1983
Creator: Hyde, R.A.
Partner: UNT Libraries Government Documents Department

Eyeglass Large Aperture, Lightweight Space Optics FY2000 - FY2002 LDRD Strategic Initiative

Description: A series of studies by the Air Force, the National Reconnaissance Office and NASA have identified the critical role played by large optics in fulfilling many of the space related missions of these agencies. Whether it is the Next Generation Space Telescope for NASA, high resolution imaging systems for NRO, or beam weaponry for the Air Force, the diameter of the primary optic is central to achieving high resolution (imaging) or a small spot size on target (lethality). While the detailed requirements differ for each application (high resolution imaging over the visible and near-infrared for earth observation, high damage threshold but single-wavelength operation for directed energy), the challenges of a large, lightweight primary optic which is space compatible and operates with high efficiency are the same. The advantage of such large optics to national surveillance applications is that it permits these observations to be carried-out with much greater effectiveness than with smaller optics. For laser weapons, the advantage is that it permits more tightly focused beams which can be leveraged into either greater effective range, reduced laser power, and/or smaller on-target spot-sizes; weapon systems can be made either much more effective or much less expensive. This application requires only single-wavelength capability, but places an emphasis upon robust, rapidly targetable optics. The advantages of large aperture optics to astronomy are that it increases the sensitivity and resolution with which we can view the universe. This can be utilized either for general purpose astronomy, allowing us to examine greater numbers of objects in more detail and at greater range, or it can enable the direct detection and detailed examination of extra-solar planets. This application requires large apertures (for both light-gathering and resolution reasons), with broad-band spectral capability, but does not emphasize either large fields-of-view or pointing agility. Despite differences in their requirements ...
Date: February 10, 2003
Creator: Hyde, R
Partner: UNT Libraries Government Documents Department

Large Diffractive Optics for GEo-Based Earth Surveillance

Description: The natural vantage point for performing Earth-centric operations from space is geosynchronous orbit (GEO); a platform there moves at the same rate as the Earth's surface, so appears to continually ''hover'' over a fixed site on the Earth. Unlike spacecraft in other orbits, which rapidly fly-over targets, a GEO-based platform remains in-position all the time. In order to insure continual access to sites using low earth orbit (LEO) platforms, one needs a large enough constellation ({approx} 50) of spacecraft so that one is always overhead; in contrast, a single GEO platform provides continuous coverage over sites throughout Euro-Asia. This permanent coverage comes, unfortunately, with a stiff price-tag; geosynchronous orbit is 36,000 km high, so space platforms there must operate at ranges roughly 100 times greater than ones located in LEO. For optical-based applications, this extreme range is difficult to deal with; for surveillance the price is a 100-fold loss of resolution, for laser weapons it is a 10,000-fold loss in flux-on-target. These huge performance penalties are almost always unacceptable, preventing us from successfully using GEO-based platforms. In practice, we are forced to either settle for brief, infrequent access to targets, or, if we demand continuous coverage, to invest in large, many-satellite, constellations. There is, fortunately, a way to use GEO-based optical platforms without incurring the huge, range-dependent, performance penalties; one must simply use bigger optics. As long as the aperture of a platform's optics increases as much as its operating range, then its performance (resolution and/or flux) does not suffer; the price for operating from GEO is simply 100-fold larger optics. This is, of course, a very stiff price; while meter-class optics may suffice for many low-earth-orbit applications, 100 meter apertures are needed in order to achieve similar performance from GEO. Since even the largest Earth-based telescope is only 10 ...
Date: September 11, 2003
Creator: Hyde, R A
Partner: UNT Libraries Government Documents Department

Large aperture Fresnel telescopes/011

Description: At Livermore we`ve spent the last two years examining an alternative approach towards very large aperture (VLA) telescopes, one based upon transmissive Fresnel lenses rather than on mirrors. Fresnel lenses are attractive for VLA telescopes because they are launchable (lightweight, packagable, and deployable) and because they virtually eliminate the traditional, very tight, surface shape requirements faced by reflecting telescopes. Their (potentially severe) optical drawback, a very narrow spectral bandwidth, can be eliminated by use of a second (much smaller) chromatically-correcting Fresnel element. This enables Fresnel VLA telescopes to provide either single band ({Delta}{lambda}/{lambda} {approximately} 0.1), multiple band, or continuous spectral coverage. Building and fielding such large Fresnel lenses will present a significant challenge, but one which appears, with effort, to be solvable.
Date: July 16, 1998
Creator: Hyde, R.A., LLNL
Partner: UNT Libraries Government Documents Department

Global warming and ice ages: I. prospects for physics based modulation of global change

Description: It has been suggested that large-scale climate changes, mostly due to atmospheric injection of greenhouse gases connected with fossil-fired energy production, should be forestalled by internationally-agreed reductions in, e.g., electricity generation. The potential economic impacts of such limitations are obviously large: greater than or equal to $10{sup 11}/year. We propose that for far smaller - less than 1% - the mean thermal effects of greenhouse gases may be obviated in any of several distinct ways, some of them novel. These suggestions are all based on scatterers that prevent a small fraction of solar radiation from reaching all or part of the Earth. We propose research directed to quite near-term realization of one or more of these inexpensive approaches to cancel the effects of the greenhouse gas injection. While the magnitude of the climatic impact of greenhouse gases is currently uncertain, the prospect of severe failure of the climate, for instance at the onset of the next Ice Age, is undeniable. The proposals in this paper may lead to quite practical methods to reduce or eliminate all climate failures.
Date: August 15, 1996
Creator: Teller, E.; Wood, L. & Hyde, R.
Partner: UNT Libraries Government Documents Department

Toward a permanent lunar settlement in the coming decade: the Columbus Project

Description: The motivation for creating a permanent lunar settlement is sketched, and reasons for doing so in the coming decade are put forward. A basic plan to accomplish this is outlined, along technical and programmatic axes. It is concluded that founding a lunar settlement on the five hundredth anniversary of the Columbus landing - a Columbus Project - could be executed as a volunteer-intensive American enterprise requiring roughly six thousand man-years of skilled endeavor and a total Governmental contribution of the order of a half-billion dollars. 8 figs.
Date: November 19, 1985
Creator: Hyde, R.A.; Ishikawa, M.Y. & Wood, L.L.
Partner: UNT Libraries Government Documents Department

Buried waste integrated demonstration Fiscal Year 1993 close-out report

Description: The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a multitude of advanced technologies. These technologies are being integrated to form a comprehensive remediation system for the effective and efficient remediation of buried waste. These efforts are identified and coordinated in support of the U.S. Department of Energy Environmental Restoration and Waste Management needs and objectives. BWID works with universities and private industry to develop these technologies, which are being transferred to the private sector for use nationally and internationally. A public participation policy has been established to provide stakeholders with timely and accurate information and meaningful opportunities for involvement in the technology development and demonstration process. To accomplish this mission of identifying technological solutions for remediation deficiencies, the Office of Technology Development initiated BWID at the Idaho National Engineering Laboratory. This report summarizes the activities of the BWID program during FY-93.
Date: April 1, 1994
Creator: Owens, K. J. & Hyde, R. A.
Partner: UNT Libraries Government Documents Department

Digface characterization test plan (remote testing)

Description: The objective of the Digface Characterization (DFC) Remote Testing project is to remotely deploy a sensor head (Mini-Lab) across a digface to determine if it can characterize the contents below the surface. The purpose of this project is to provide a robotics technology that allows removal of workers from hazards, increases speed of operations, and reduces life cycle costs compared to alternate methods and technologies. The Buried Waste Integrated Demonstration (BWID) is funding the demonstration, testing, and evaluation of DFC. This document describes the test plan for the DFC remote deployment demonstration for the BWID. The purposes of the test plan are to establish test parameters so that the demonstration results are deemed useful and usable and perform the demonstration in a safe manner and within all regulatory requirements.
Date: August 1, 1993
Creator: Croft, K.; Hyde, R. & Allen, S.
Partner: UNT Libraries Government Documents Department

Comparison of normal and asthmatic subjects' responses to sulfate pollutant aerosols

Description: Epidemiological studies support an association between elevated levels of sulfates and acute respiratory disease. To determine if these pollutants produce airway hyperreactivity, 16 normal and 17 asthmatic subjects inhaled a control NaCl aerosol and the following sulfates: ammonium sulfate, sodium bisulfate, ammonium bisulfate, and sulfuric acid. A Lovelace generator produced particles with an average MMAD of approx. 1.0 ..mu..m (sigma/sub g/ approx. = 2.0) and concentrations of 0.1 and 1.0 mg/m/sup 3/. By double-blind randomization, all subjects breathed these aerosols for a 16-minute period. To determine if sulfate inhalation caused increased reactivity to a known bronchoconstrictor, all subjects inhaled carbachol following each 16-minute exposure. Before, during, and after exposure, pulmonary function studies were performed. When compared to NaCl, sulfate (1 mg/m/sup 3/) produced significant reductions in airway conductance and flow rates in asthmatics. The two most sensitive asthmatics demonstrated changes even at 0.1 mg/m/sup 3/ sulfate. To a far more significant degree, the bronchoconstrictor action of carbachol was potentiated by sulfates more or less in relation to their acidity in normals and asthmatics.
Date: January 1, 1980
Creator: Utell, M. J.; Morrow, P. E. & Hyde, R. W.
Partner: UNT Libraries Government Documents Department

Integrated approach to hazardous and radioactive waste remediation

Description: The US Department of Energy Office of Technology Development is supporting the demonstration, and evaluation of a suite of waste retrieval technologies. An integration of leading-edge technologies with commercially available baseline technologies will form a comprehensive system for effective and efficient remediation of buried waste throughout the complex of DOE nuclear facilities. This paper discusses the complexity of systems integration, addressing organizational and engineering aspects of integration as well as the impact of human operators, and the importance of using integrated systems in remediating buried hazardous and radioactive waste.
Date: November 1, 1994
Creator: Hyde, R. A. & Reece, W. J.
Partner: UNT Libraries Government Documents Department

Remote Excavation System Test Plan

Description: The Office of Technology Development (OTD) established the Robotics Technology Development Program (RTDP) to integrate robotic development activities on a national basis; provide needs-oriented, timely, and economical robotics technology to support environmental and waste operations activities at Department of Energy (DOE) sites; and provide the focus and direction for the near term (less than five years) and guidance for the tong-term (five to twenty years) research and development efforts for site-specific problems. The RTDP consists of several programs including the Buried Waste Robotics Program (BWRP), which addresses remote buried waste applications. The Remote Excavation System (RES) was developed under the RTDP to provide a safer method of excavating hazardous materials for both the DOE and the Department of Defense (DOD). The excavator, initially developed by the DOD as a manually-operated small excavator, has been modified for teleoperation with joint funding from the BWRP and the DOD. The Buried Waste Integrated Demonstration (BWID) and the Uranium Soils Integrated Demonstration (USID) are funding the demonstration, testing, and evaluation of the RES covered in this test plan. This document covers testing both at Oak Ridge National Laboratory (ORNL) and the Idaho National Engineering Laboratory (INEL), as funded by BWID and USID. This document describes the tests planned for the RES demonstration for the BWRP. The purposes of the test plan are (1) to establish test parameters to ensure that the demonstration results are deemed useful and usable and (2) to demonstrate performance in a safe manner within all regulatory requirements.
Date: May 1, 1993
Creator: Walker, S. & Hyde, R. A.
Partner: UNT Libraries Government Documents Department

Twenty Meter Space Telescope Based on Diffractive Fresnel Lens

Description: Diffractive lenses offer two potential advantages for very large aperture space telescopes; very loose surface-figure tolerances and physical implementation as thin, flat optical elements. In order to actually realize these advantages one must be able to build large diffractive lenses with adequate optical precision and also to compactly stow the lens for launch and then fully deploy it in space. We will discuss the recent fabrication and assembly demonstration of a 5m glass diffractive Fresnel lens at LLNL. Optical performance data from smaller full telescopes with diffractive lens and corrective optics show diffraction limited performance with broad bandwidths. A systems design for a 20m space telescope will be presented. The primary optic can be rolled to fit inside of the standard fairings of the Delta IV vehicle. This configuration has a simple deployment and requires no orbital assembly. A twenty meter visible telescope could have a significant impact in conventional astronomy with eight times the resolution of Hubble and over sixty times the light gathering capacity. If the light scattering is made acceptable, this telescope could also be used in the search for terrestrial planets.
Date: June 26, 2003
Creator: Early, J; Hyde, R & Baron, R
Partner: UNT Libraries Government Documents Department

Civilian Power from Space in the Early 21st Century

Description: If power beamed from space is to be become widely used on Earth in the first half of the 21St century, several thus-far-persistent impediments must be obviated, including threshold effects and problematic aspects of cost, availability, reliability, hazards and environmental impacts. We sketch a generally-applicable route to doing so, noting key enabling technologies and practical features. Likely-essential features of any successful strategy include vigorous, systematic leveraging of all intrinsic features of space-derived power, e.g., addressing marginal, high-value-added markets for electric power in space- and time-agile manners to conveniently provide power-upon-demand, and incrementally ''wedging'' into ever-larger markets with ever more cost-efficient generations and scales of technology. We suggest that no prudent strategic plan will rely upon large-scale, long-term public subsidies--fiscal, regulatory, etc.--with their attendant ''sovereign risks'' and interminable delays, and that plan-essential governmental support likely will be limited to early feasibility demonstrations, provision of threshold technologies and a rational, competition-neutral licensing environment. If salient realities are uniformly respected and accessible technologies are intelligently leveraged, electricity derived from space-sourced power-beams may come into significant civilian use during the latter part of the first quarter of this century, and may become widely used by the half-century point.
Date: June 1, 2003
Creator: Hyde, R; Ishikawa, M & Wood, L
Partner: UNT Libraries Government Documents Department

Cooperative Telerobotic Retrieval system Phase 1 technology evaluation report

Description: This document describes the results from the Cooperative Telerobotic Retrieval demonstration and testing conducted at the Idaho National Engineering Laboratory during December 1994 and January 1995. The purpose of the demonstration was to ascertain the feasibility of the system for deploying tools both independently and cooperatively for supporting remote characterization and removal of buried waste in a safe manner and in compliance with all regulatory requirements. The procedures and goals of the demonstration were previously defined in the Cooperative Telerobotic Retrieval System Test Plan for Fiscal Year 1994, which served as a guideline for evaluating the system.
Date: March 1, 1995
Creator: Hyde, R.A. & Croft, K.M.
Partner: UNT Libraries Government Documents Department

An integrated systems approach to remote retrieval of buried transuranic waste using a telerobotic transport vehicle, innovative end effector, and remote excavator

Description: Between 1952 and 1970, over two million cubic feet of transuranic mixed waste was buried in shallow pits and trenches in the Subsurface Disposal Area at the Idaho National Engineering Laboratory Radioactive Waste Management Complex. Commingled with this two million cubic feet of waste is up to 10 million cubic feet of fill soil. The pits and trenches were constructed similarly to municipal landfills with both stacked and random dump waste forms such as barrels and boxes. The main contaminants are micron-sized particles of plutonium and americium oxides, chlorides, and hydroxides. Retrieval, treatment, and disposal is one of the options being considered for the waste. This report describes the results of a field demonstration conducted to evaluate technologies for excavating, and transporting buried transuranic wastes at the INEL, and other hazardous or radioactive waste sites throughout the US Department of Energy complex. The full-scale demonstration, conduced at RAHCO Internationals facilities in Spokane, Washington, in the summer of 1994, evaluated equipment performance and techniques for digging, dumping, and transporting buried waste. Three technologies were evaluated in the demonstration: an Innovative End Effector for dust free dumping, a Telerobotic Transport Vehicle to convey retrieved waste from the digface, and a Remote Operated Excavator to deploy the Innovative End Effector and perform waste retrieval operations. Data were gathered and analyzed to evaluate retrieval performance parameters such as retrieval rates, transportation rates, human factors, and the equipment`s capability to control contamination spread.
Date: February 1, 1995
Creator: Smith, A.M.; Rice, P.; Hyde, R. & Peterson, R.
Partner: UNT Libraries Government Documents Department

Risk and cost tradeoffs for remote retrieval of buried waste

Description: The Buried Waste Integrated Demonstration is supporting the development, demonstration, testing, and evaluation of a suite of technologies that, when integrated with commercially available technologies, form a comprehensive system for the remediation of radioactive and hazardous buried waste. As a part of the program`s technology development, remote retrieval equipment is being developed and tested for the remediation of buried waste. During remedial planning, several factors are considered when choosing remote versus manual retrieval systems. Time that workers are exposed to radioactivity, chemicals, air particulate, and industrial hazards is one consideration. The generation of secondary waste is also a consideration because it amounts to more waste to treat and some wastes may require special handling or treatment. Cost is also a big factor in determining whether remote or manual operations will be used. Other considerations include implementability, effectiveness, and the number of required personnel. This paper investigates each of these areas to show the risk and cost benefits and limitations for remote versus manual retrieval of buried waste.
Date: December 31, 1994
Creator: Hyde, R.A.; Grienbenow, B.E. & Nickelson, D.F.
Partner: UNT Libraries Government Documents Department

Problem free nuclear power and global change

Description: Nuclear fission power reactors represent a solution-in-principle to all aspects of global change possibly induced by inputting of either particulate or carbon or sulfur oxides into the Earth`s atmosphere. Of proven technological feasibility, they presently produce high- grade heat for electricity generation, space heating and industrial process-driving around the world, without emitting greenhouse gases or atmospheric particulates. However, a substantial number of major issues currently stand between nuclear power implemented with light- water reactors and widespread substitution for large stationary fossil fuel-fired systems, including long-term fuel supply, adverse public perceptions regarding both long-term and acute operational safety, plant decommissioning, fuel reprocessing, radwaste disposal, fissile materials diversion to military purposes and - perhaps more seriously - cost. We describe a GW-scale, high-temperature nuclear reactor heat source that can operate with no human intervention for a few decades and that may be widely acceptable, since its safety features are simple, inexpensive and easily understood. We provide first-level details of a reactor system designed to satisfy these requirements. Such a back-solving approach to realizing large-scale nuclear fission power systems potentially leads to an energy source capable of meeting all large-scale stationary demands for high- temperature heat. If widely employed to support such demands, it could, for example, directly reduce present-day world-wide CO{sub 2} emissions by two-fold; by using it to produce non-carbonaceous fuels for small mobile demands, a second two-fold reduction could be attained. Even the first such reduction would permit continued slow power-demand growth in the First World and rapid development of the Third World, both without any governmental suppression of fossil fuel usage.
Date: August 15, 1997
Creator: Teller, E.; Wood, L.; Nuckolls, J.; Ishikawa, M. & Hyde, R.
Partner: UNT Libraries Government Documents Department

Cosmic bombardment V: Threat object-dispersing approaches to active planetary defense

Description: Earth-impacting comets and asteroids with diameters {approx}0.03 - 10 km pose the greatest threats to the terrestrial biosphere in terms of impact frequency-weighted impact consequences, and thus are of most concern to designers of active planetary defenses. Specific gravitational binding energies of such objects range from 10{sup -7} to 10{sup -2} J/gm, and are small compared with the specific energies of 1x10{sup 3} to 3x10{sup 3} J/gm required to vaporize objects of typical composition or the specific energies required to pulverize them, which are 10{sup -1} to 10 J/gm. All of these are small compared to the specific kinetic energy of these objects in the Earth- centered frame, which is 2x10{sup 5} to 2x10{sup 6} J/gm. The prospect naturally arises of negating all such threats by deflecting, pulverizing or vaporizing the objects. Pulverization-with-dispersal is an attractive option of reasonable defensive robustness. Examples of such equipments - which employ no explosives of any type - are given. Vaporization is the maximally robust defensive option, and may be invoked to negate threat objects not observed until little time is left until Earth-strike, and pulverization-with-dispersal has proven inadequate. Physically larger threats may be vaporized with nuclear explosives. No contemporary technical means of any kind appear capable of directly dispersing the -100 km diameter scale Charon- class cometary objects recently observed in the outer solar system, although such objects may be deflected to defensively useful extents. Means of implementing defenses of each of these types are proposed for specificity, and areas for optimization noted. Biospheric impacts of threat object debris are briefly considered, for bounding purposes. Experiments are suggested on cometary and asteroidal objects.
Date: May 24, 1995
Creator: Teller, E.; Wood, L.; Ishikawa, M. & Hyde, R.
Partner: UNT Libraries Government Documents Department

Operable Unit 7-13/14 in situ thermal desorption treatability study work plan

Description: This Work Plan provides technical details for conducting a treatability study that will evaluate the application of in situ thermal desorption (ISTD) to landfill waste at the Subsurface Disposal Area (SDA) at the Idaho National Engineering and Environmental Laboratory (INEEL). ISTD is a form of thermally enhanced vapor vacuum extraction that heats contaminated soil and waste underground to raise its temperature and thereby vaporize and destroy most organics. An aboveground vapor vacuum collection and treatment system then destroys or absorbs the remaining organics and vents carbon dioxide and water to the atmosphere. The technology is a byproduct of an advanced oil-well thermal extraction program. The purpose of the ISTD treatability study is to fill performance-based data gaps relative to off-gas system performance, administrative feasibility, effects of the treatment on radioactive contaminants, worker safety during mobilization and demobilization, and effects of landfill type waste on the process (time to remediate, subsidence potential, underground fires, etc.). By performing this treatability study, uncertainties associated with ISTD as a selected remedy will be reduced, providing a better foundation of remedial recommendations and ultimate selection of remedial actions for the SDA.
Date: May 1, 1999
Creator: Shaw, P.; Nickelson, D. & Hyde, R.
Partner: UNT Libraries Government Documents Department

WET MARS: plentiful, readily-available martian water and its implications

Description: Water and its major constituent, oxygen, in large specific quantities are essential for maintenance of human life. Providing them in adequate quantities is widely believed to be a major challenge for human Mars exploration and settlement. The Martian regolith isn't known to bear either water or hydrogen, the ice-rich Martian polar regions are thermally inhospitable, and the measured water content of Mars' thin atmosphere represents a layer of liquid water of average thickness only about 1% that of the Moon: {approximately}0.001 cm. Crucially, however, the atmospheric Martian water inventory is advected to everyplace on Mars by meteorological phenomena, so that the few cubic kilometers of liquid water-equivalent in the atmosphere are available most anywhere when, merely for the effort of condensing it. Well-engineered apparatus deployed essentially anywhere on Mars can condense water from the atmosphere in daily quantities not much smaller than its own mass, rejecting into space from radiators deployed over the local terrain the water's heat-of-condensation and the heat from non-ideality of the equipment's operation. Thus, an optimized, photovoltaically-powered 0.3 ton water-condensing system could strip 40 tons of water each year from {approximately}10{sup 4} times this mass of thin, dry Martian air. Given a 480 set I{sub sp} of H{sub 2}-O{sub 2} propulsion systems exhausting into the 6 millibar Mars-surface atmosphere and the 5.0 km/s Martian gravity well, {ge}40 tons of water two-thirds converted into 5:1 O{sub 2}/H{sub 2} cryogenic fuel could support exploration and loft a crew-of-four and their 8-ton ascent vehicle into Earth-return trajectory. The remaining water and excess oxygen would suffice for half-open-cycle life support for a year's stay on Mars. A Mars Expedition thus needs to land only explorers, dehydrated food, habitation gear and unfueled exploration I Earth-return equipment - and a water/oxygen/fuel plant with embedded power supply which operates on Martian atmospheric water. ...
Date: August 12, 1999
Creator: Hyde, R; Ishikawa, M; Nuckolls, J; Whitehead, J & Wood, L
Partner: UNT Libraries Government Documents Department

Cosmic Bombardment IV: Averting catastrophe in the here-and-now

Description: At the present time, it is at least arguable that large-scale cosmic bombardment has been a major driver of the evolution of the terrestrialbiosphere. The fundamental motivation of the present paper is the (high) likelihood that the advent and rise of the human species hasn`t coincided with the cessation of soft and hard collisions in the Asteroid Belt or in the Oort Cloud, and that we will either stop the cosmic bombardment or it will eventually stop us. In the foregoing, briefly reviewed the prospects for active planetary defenses against cosmic bombardment in the very near-term, employing only technologies which exist now and could be brought-to-bear in a defensive system on a one-decade time-scale. We sketch various means and mechanisms from a physicist`s viewpoint by which such defensive systems might detect threat objects, launch interdiction machinery toward them and operate such machinery in their vicinity to alternately deflect, disperse or vaporize objects in the 0.1-10 km-diameter range, the ones whose size and population constitute the greatest threats to our biosphere. We conclude that active defenses of all types are readily feasible against 0.1 kmdiameter incoming cosmic bomblets and that even complete vaporization-class defenses are feasible against 1 km-diameter class objects of all compositions. When facing Great Extinctors of up to 10 km diameter, the feasible defensive methods depend upon the object`s size and composition. Dispersion defenses are feasible against all threat-classes, as are deflection approaches for bomblets up to {approximately} 10 km diameter; vaporization-level protection is, however, available only against dirty snowballs` of the {approximately} 1--2 km diameter class. Great Extinctors of sizes significantly greater than 10 km diameter challenge contemporary human technology ever more severely; fortunately, they appear to be rare on the several Aeon time-scales over which Sol will shift its spectral class.
Date: September 23, 1994
Creator: Wood, L.; Hyde, R.; Ishikawa, M. & Ledebuhr, A.
Partner: UNT Libraries Government Documents Department

An overview of in situ waste treatment technologies

Description: In situ technologies are becoming an attractive remedial alternative for eliminating environmental problems. In situ treatments typically reduce risks and costs associated with retrieving, packaging, and storing or disposing-waste and are generally preferred over ex situ treatments. Each in situ technology has specific applications, and, in order to provide the most economical and practical solution to a waste problem, these applications must be understood. This paper presents an overview of thirty different in situ remedial technologies for buried wastes or contaminated soil areas. The objective of this paper is to familiarize those involved in waste remediation activities with available and emerging in situ technologies so that they may consider these options in the remediation of hazardous and/or radioactive waste sites. Several types of in situ technologies are discussed, including biological treatments, containment technologies, physical/chemical treatments, solidification/stabilization technologies, and thermal treatments. Each category of in situ technology is briefly examined in this paper. Specific treatments belonging to these categories are also reviewed. Much of the information on in situ treatment technologies in this paper was obtained directly from vendors and universities and this information has not been verified.
Date: January 1, 1992
Creator: Walker, S.; Hyde, R.A.; Piper, R.B. & Roy, M.W.
Partner: UNT Libraries Government Documents Department

Fabrication and applications of large aperture diffractive optics

Description: Large aperture diffractive optics are needed in high power laser applications to protect against laser damage during operation and in space applications to increase the light gathering power and consequently the signal to noise. We describe the facilities we have built for fabricating meter scale diffractive optics and discuss several examples of these.
Date: February 19, 2002
Creator: Dixit, S; Britten, J B; Hyde, R; Rushford, M; Summers, L & Toeppen, J
Partner: UNT Libraries Government Documents Department