摘要:

The estimated propellant production cost per metric ton will be derived and presented for solar system transportation waypoints. Background on recent and ongoing space resource propellant supply models will be presented, with a review of architectural assumptions, costs and expected markets. Integrated economic and engineering models (Duke et al., 2003; Duke, Blair and Diaz, 2002; Lamassoure et al. 2003; and Blair et al., 2002) estimate production costs, expected productivity of the mining and processing system, reusable transportation element behavior, fuel depot activity and revenues based on projected market conditions. Results of these economic models are used to derive total and marginal unit costs for propellant at fuel depot facilities for the purpose of facilitating the commercial development of space and to aid program and logistic planning for human space exploration missions. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649671

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The Methane to Aromatics on Mars (METAMARS) system is anin situresource utilization (ISRU) technique that converts methane produced from the carbon dioxide in the martian atmosphere to low hydrogen content liquid aromatic fuels for an Earth Return Vehicle, thus greatly increasing the leverage of the hydrogen imported from the Earth. More importantly, the METAMARS system reduces the amount of hydrogen imported from Earth by a factor of four, leading to dramatic reductions in mission cost. This project involves design and construction of two fully functional oxygen/aromatic hydrocarbon production facilities (brassboard and protoflight) sized to produce 1 kg of bipropellant per day. Because aromatic fuels contain only about one hydrogen atom per carbon atom, the METAMARS system gives extremely high leverages on the order of 53 in the production of fuel and oxidizer for a Mars Sample Return (MSR) mission and human Mars missions. In addition, there are extensive potential commercial applications for the technology in converting trillions of cubic feet of stranded natural gas into easily transportable liquid aromatic products. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649672

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The interaction between water and reduced ilmenite samples as produced in a hydrothermal reduction process has been investigated at temperature of 1070 and 1223 K utilizing a Ugine‐Setaram Thermobalance coupled with a mass‐spectrometer. The experimental data show that the process of oxidation of reduced ilmenite is feasible at high temperature giving rise to the formation of FeO and Fe2O3at different stages of oxidation. The process occurs according to the reactions: Fe(s), TiO2(s) (reduced ilmenite)+H2O(g)=FeO(s)+TiO2(s)+H2(g) and 2 FeO(s), 2 TiO2(s)+H2O(g)=Fe2O3(s)+2 TiO2(s)+H2(g). The oxidative process has been investigated as a function of water partial pressure in an argon carrier and as a function of the granulometry of the powder. An analysis of the residue before and after the oxidation process shows some peculiarities in the morphology of the condensed phase that will be discussed in the paper. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649673

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

When large space settlements are finally built, inevitably the customers who pay for them will start the process by specifying requirements with a Request for Proposal (RFP). Although we are decades away from seeing the first of these documents, some of their contents can be anticipated now, and provide insight into the variety of elements that must be researched and developed before space settlements can happen. Space Settlement Design Competitions for High School students present design challenges in the form of RFPs, which predict basic requirements for space settlement attributes in the future, including structural features, infrastructure, living conveniences, computers, business areas, and safety. These requirements are generically summarized, and unique requirements are noted for specific space settlement locations and applications. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649674

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The main problem with terraforming is finding planets with workable initial parameters: large enough, temperate enough, wet enough, axial spin not too fast or too slow, a magnetic field, etc. We consider a novel method of creating habitable worlds for humanity by enclosing airless and sterile planets, moons, and even large asteroids within engineered shells supported by breathable atmospheres. Beneath the shell an earthlike environment could be formed similar in almost all respects to that of Earth except for gravity, regardless of the distance to the sun or other star. These would be natural worlds, not merely large habitats, stable across historic timescales at least, each comprising a full self‐sustaining ecology, which might evolve in interesting and distinct directions over time. This approach requires no fundamental breakthroughs in science or physics but does require progress in energy production, space transportation, and environmental and materials sciences. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649675

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Recent reports have claimed that high‐temperature superconductors can interact with gravitation under certain non‐relativistic conditions. Only two such reports have been peer‐reviewed: the first, describing changes in the weight of test masses, was by Podkletnov and Nieminen (1992); the other, reporting large‐amplitude gravitational wave generation in a laboratory, was by Podkletnov and Modanese (2003). Common to these reports is the claim that the observed gravitational field may be modified using YBa2Cu3O7−&dgr;(YBCO) below its superconducting critical temperature,Tc∼ 93K, and in a magnetic fieldB∼ 1T. Temperatures below 70K gave the largest effects. The first experiment used magnetically levitated YBCO rotated at ∼5000 rpm; the second experiment did not spin or levitate the YBCO, but used a 2MV electrical discharge in a vacuum chamber. Several attempts have been made world‐wide to replicate the first of these experiments, although no peer‐reviewed reports have yet confirmed the observations. No known replications of the second experiment have been completed so far. A number of papers have presented theoretical models for the effects. This paper reviews the current experimental and theoretical scientific evidence regarding these experiments, together with further tests implied by the published explanations. The discussion includes a classical suggestion (due to Landau and Lifshitz) that gravitational waves can modify gravitational fields, Aquino’s theory based upon electromagnetic fields, and Desbrandes’s calculation to explain the Podkletnov and Nieminen results on the basis of gravity waves emitted from the Cooper pairs inside a superconductor. The conclusions are that these experiments are extremely difficult to replicate and that no complete replication confirming the effects has yet taken place. By contrast, no‐one has conclusively disproved the existence of the effects. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649676

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

High‐Frequency Gravitational Wave (HFGW) generators are separated into three general categories. Precursor, component‐validation, laboratory experiments for each category except, possibly, the third are identified in general terms. The categories are: (1) The electromechanical category includes micro‐ and nano‐element, piezoelectric crystal, and multi‐dielectric film HFGW generators. (2) The high‐temperature superconductor category includesgasers, impressed magnetic fields, and transformation of electromagnetic radiation into gravitational waves (Gertsenshtein effect) HFGW generators. (3)The laser/plasma category includes laser‐energized mirrors, synchrotron light, nuclear fusion, plasma toroid, and nonlinear optical‐acoustical, molecular‐level HFGW generators. A perusal of HFGW literature reveals that since the 1960s many authors have contributed designs of mechanisms and devices that relate to the terrestrial generation of gravitational waves. Only in the last few years, however, have any researchers demonstrated that their proposed devices were practical HFGW generators, capable of producing kilowatts of power, that were operational in a laboratory setting. These recent devices make use of new technology and generate high‐frequency (GHz and above) gravitational waves using non‐gravitational forces. Most of the generators considered in this paper have been recently discussed at the May, 2003,Gravitational Wave Conferenceat The MITRE Corporation, McLean, VA, which was the very first International Conference dedicated to HFGW and attracted twenty‐five research papers from nine countries. Although no detailed experimental tasks are discussed, experimental test objectives in the form of a roadmap are proposed for each category. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649677

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

During the 2003 STAIF Conference, the author proposed a theory based upon gravitational anomalies, that would use a universal gravitation model with a radial force term coupled with angular momentum. This extended the previous work of Murad and Baker, Dyatlov who explains angular momentum effects as consequences of a ‘spin’ field, and also of Jefimenko. Angular momentum may explain various spin asymmetries allowing the transfer of gravitational radiation directly into angular momentum observed in some anomalous gyroscope experiments; planets orbiting around the sun; moons orbiting larger planetary bodies; and planetary rotation direction. Moreover, a decrease in rotation of a rapidly spinning neutron star may be due to generating gravitational waves as the star loses energy and angular momentum in a tangential direction by changes within its gravitational field. Similarly a coalescing binary black hole “loses” up to 12&percent; of its total angular momentum. A High‐Frequency Gravitational Wave (HFGW) experiment using a mini‐synchrotron could test this proposed theory. Results suggest Jefimenko’s cogravity field may represent the elusive ‘spin’ or ‘torsion’ field. The model also indicates gravity strength may increase with the speed of a moving body or spacecraft. Finally, if true, these new effects can have a revolutionary impact upon theoretical physics and Astronautics. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649678

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In this paper a series of proof‐of‐concept, precursor experiments are identified. Three specific component‐validation, laboratory experimental tasks are described: the first involves the generation of a series of microsecond, nanosecond, and picosecond current pulses utilizing off‐the‐shelf pulse generators and even shorter pulses utilizing state‐of‐the‐art equipment. It is recognized that the power of the HFGW generation is inversely proportional to the square of the pulse length, &Dgr;t, so that short pulse length (and high frequency of a train of pulses) is most desirable. The second task is to utilize the aforementioned pulses to energize, jerk, or otherwise cause a third‐time‐derivative change in motion of a test mass, termed an energizable element. The third task involves the ability to measure the motion of the test mass at megahertz, gigahertz, terahertz and other higher vibrational or jerk frequencies. Specific off‐the‐shelf laboratory equipment and their cost are listed. The energizing elements will involve small coils, activated by current pulses and/or electromagnetic pulses, to energize a small magnet and laser pulses to energize a small mirror or energize other nano‐ or micro‐devices. Once the mechanism for producing the jerk is validated in these tasks (by verifying that the energizing pulses or elements energize or jerk of the energizable element), then that mechanism can be replicated. Those replicated mechanisms can be utilized as micro‐ or nano‐elements in devices that will be now capable of generating HFGW. In this regard, an attosecond‐pulse‐duration, 6 KW HFGW generator is discussed. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649679

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The generation of High‐Frequency Gravitational Waves (HFGW) has been identified as the required breakthrough that will lead to new forms of space propulsion. Many techniques have been devised to generate HFGW, but most of them exhibit marginal efficiency, therefore the power emitted in form of gravitational waves (GW) is orders of magnitude lower than the input power. The gravitational wave counterpart of the LASER, termed Gravitational‐wave LASER or “GASER” is the quantum approach to the efficient generation of gravitational waves. Electrons, protons, muons, etc, all have charge and mass, if accelerated they usually lose energy through the very fast electric and magnetic channels, this causes a negligible emission through the gravitational channel. Quantum systems can be engineered to forbid electric and magnetic transitions, therefore the gravitational spin‐2 transitions can take place. A class of active materials, suitable for making a GASER based on electronic transitions in the solid state, is identified along with their relevant physical properties. Means for creating coherence and population inversion and means to increase the emission probability are described. The expected performances of the device are derived from quantum gravitational theories. Additional properties of the active materials are considered to enforce the theoretical foundation of the device. A proof‐of‐concept device, operating at about 1 THz, is described. Experiments are proposed as a natural starting point of the research. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1649680

出版商:AIP    

年代:1904

数据来源: AIP