Engineering topics

Clark, Benton C.

Publications and source records attributed to Clark, Benton C..

31 records · Page 2

NASA NTRS1993

Mars aqueous chemistry experiment

The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

Clark, Benton C.↗

NASA NTRS1992

Implications for volcanogenic volatile release on the weathering of Mars

Volcanism on Mars has been widespread in both space and time. Notwithstanding important specific differences between the mantles of Earth and Mars, the similarities are such that the suite of gases emitted from martian volcanic activity surely includes gases such as H2O, CO2, S-containing gases (H2S, SO3, or SO2), and Cl-containing gases (e.g. Cl or HCl). Both H2O and CO2 are present in the atmosphere of Mars; both are also present as surface condensates. Spectroscopic observations of the martian atmosphere clearly show that the S- and Cl-containing gases are severely depleted. Likewise, there is no evidence of surface condensates of compounds of these elements. Within the soil, there is direct evidence of incorporation of H2O and some compounds of sulfur and chlorine. None of the resultant weathering products have been directly identified, but both clays and salts have been indirectly implicated. Other aspects of the implications for volcanogenic volatile release on the weathering of Mars are discussed.

Clark, Benton C.↗

NASA NTRS1991

Survey of resource opportunities and critical evaluation of economic requirements

A series of mission analyses were performed to evaluate human mission to Mars and the moon with and without the aid of planetary resource utilization. The types of trade studies that are considered include the use of resources to manufacture propellant, food, habitat atmospheric gases, and lander habitat structure. Also, the potential for export of resources from the moon, Mars, Phobos, Deimos, and selected asteroids is also examined. In all cases, mass leveraging is evaluated. For certain cases, economic factors are evaluated as well. It is concluded that some uses are highly leveraging on the mission, whereas others have lesser impact and, therefore, should be afforded lesser priority in resource utilization studies. This survey is made with a consistent set of scaling laws for spacecraft propulsion and habitation systems and subsystems, and therefore, provides a rational basis for comparing different resource locations and use strategies.

Clark, Benton C.↗

NASA NTRS1991

Physical and chemical properties of the Martian soil: Review of resources

The chemical and physical properties of Martian surface materials are reviewed from the perspective of using these resources to support human settlement. The resource potential of Martian sediments and soils can only be inferred from limited analyses performed by the Viking Landers (VL), from information derived from remote sensing, and from analysis of the SNC meteorites thought to be from Mars. Bulk elemental compositions by the VL inorganic chemical (x ray fluorescence) analysis experiments have been interpreted as evidence for clay minerals (possibly smectites) or mineraloids (palagonite) admixed with sulfate and chloride salts. The materials contained minerals bearing Fe, Ti, Al, Mg and Si. Martian surface materials may be used in many ways. Martian soil, with appropriate preconditioning, can probably be used as a plant growth medium, supplying mechanical support, nutrient elements, and water at optimal conditions to the plants. Loose Martian soils could be used to cover structures and provide radiation shielding for surface habitats. Martian soil could be wetted and formed into abode bricks used for construction. Duricrete bricks, with strength comparable to concrete, can probably be formed using compressed muds made from martian soil.

Stoker, C. R.↗

NASA NTRS1990

Carbon-rich particles in Comet Halley

The majority of particles detected in the coma of Comet Halley contain carbon atoms; many of these grains appear to consist preponderately or only of light elements. These light-element particles may be composed of organic compounds. Of the possible combinations of the elements hydrogen, carbon, nitrogen, and oxygen, numerous examples are found of particles containing the combinations (H,C,O,N), (H,C,N), (H,C,O), and (H,C). These results may bear on the recent detection of polyoxymethylene fragments, the observation of cyanojets (CN patterns consistent with release from solid particles), the possible presence of cyanopolyacetylenes or HCN polymer and the make-up of the CHON particles. If cometary matter could reach the surface of the earth without complete disruption, these diverse organic and mixed particles could create unique microenvironments, possibly with significant or even pivotal prebiotic chemical activity. Here a speculative insight into possible relationships between carbon in comets and carbon in life is given, as well as a brief overview of on-going analysis of data from the highly successful Particle Impact Analyzer (PIA) experiment flown on the Giotto spacecraft for the flyby of Comet Halley (development and implementation of PIA was under the direction of J. Kissel of the Max Planck Institute for Kernphysik, Heidelberg). PIA is a time-of-flight analyzer which obtains mass spectra of ions from individual particles impacting on a Pt-Ag foil target within the instrument.

Clark, Benton C.↗

NASA NTRS1989

Artificial gravity Mars spaceship

Experience gained in the study of artificial gravity for a manned trip to Mars is reviewed, and a snowflake-configured interplanetary vehicle cluster of habitat modules, descent vehicles, and propulsion systems is presented. An evolutionary design is described which permits sequential upgrading from five to nine crew members, an increase of landers from one to as many a three per mission, and an orderly, phased incorporation of advanced technologies as they become available.

Clark, Benton C.↗

NASA NTRS1988

Technological innovations for human outposts on planetary bodies

Technology developments which have applications for establishing man-tended outposts on the moon and Mars are reviewed. The development of pressurized rovers and computer-aided control, repair, and manufacturing is discussed. The possibility of utilizing aerodynamic drag by optimizing dynamic pressure to accomplish the necessary spacecraft velocity reduction for planetary orbital capture is considered and research in the development of artificial gravity is examined.

Clark, Benton C.↗

NASA NTRS1988

Crew activities, science, and hazards of manned missions to Mars

The crew scientific and nonscientific activities that will occur at each stage of a mission to Mars are examined. Crew activities during the interplanetary flight phase will include simulations, maintenance and monitoring, communications, upgrading procedures and operations, solar activity monitoring, cross-training and sharpening of skills, physical conditioning, and free-time activities. Scientific activities will address human physiology, human psychology, sociology, astronomy, space environment effects, manufacturing, and space agriculture. Crew activities on the Martian surface will include exploration, construction, manufacturing, food production, maintenance and training, and free time. Studies of Martian geology and atmosphere, of the life forms that may exist there, and of the Martian moons will occur on the planet's surface. Crew activities and scientific studies that will occur in Mars orbit, and the hazards relevant to each stage of the mission, are also addressed.

Clark, Benton C.↗

NASA NTRS1988

Transportation concepts for Mars exploration

The transportation aspects of astronaut travel to Mars are discussed. Alternative types of propulsion are examined, including mainline and ancillary chemical propulsion, electric propulsion, and nuclear thermal rocket propulsion. The possibility of remote propellant production is presented, focusing on the use of lunar liquid oxygen, Phobos propellants and Mars propellant production. Also, the way in which habitat models may be derived from Space Station modules or from other designs capitalizing on larger diameter payload envelopes for heavy-lift launch vehicles is considered.

Clark, Benton C.↗

NASA NTRS1988

Human exploration of Mars

A systems study is underway of astronaut missions to Mars that could be accomplished over the next four decades. In addition to an emphasis on the transportation and facility infrastructure required for such missions, other relevant technologies and mission constraints are also being considered. These induce on-orbit assembly, trajectory type, launch opportunities, propellant storage, crew size, cabin pressure, artificial gravity, life-support systems, radiation hazards, power/energy storage, thermal control, human factors, communications, abort scenarios, landing techniques, exploration strategies, and science activities. A major objective of the study is to identify enabling and significantly enhancing technologies for accomplishing the goal of the human exploration of Mars.

Clark, Benton C.↗

NASA NTRS1988

Long-range exploration by humans on the surface of Mars

A major objective of missions to Mars will be to conduct reconnaissance and to explore the surface. Systems that will allow astronauts to operate freely in the Martian environment are discussed. Special consideration is given to the design of manned rovers and to the safety and science issues involved. To conduct a wide-ranging exploration, a sortie time of at least 7 Martian days and an adequate fuel/power source are needed for at least a 100-km range. The concept of a hybrid rover is proposed, that will fulfill these requirements. In the Hybrid Rover, the driver of the vehicle will transport a space-suit-wearing astronaut to the area of interest, where the 'suitman' will demount and conduct typical field geological exploration, while the driver will continue to reconnoiter the area, and/or conduct independent sampling sorties using manipulator arms. Attention is also given to the design of a life support system. For fulfilling the power requirements of transportation and a power-intensive closed-cycle life supporting system, nuclear power is being considered as one of the possible power sources.

Clark, Benton C.↗

NASA NTRS1987

Elemental composition of the Martian surface

The Viking landers carried X-ray fluorescence spectrometers (XRFS) to the surface of Mars for direct in-situ measurements of the elemental composition of samples that could be acquired by the surface sampler scoops. A total of 21 samples at two landing sites were acquired and analyzed. In this review, the constraints imposed on the design and operation of the XRFS; the accuracy and precision limitations of XRF; and the interpretation of the results are discussed. The latter includes relevance of the investigation to Martian geological processes, SNC meteorites, the formation and history of Mars, and future mission objectives/capabilities.

Clark, Benton C.↗

NASA NTRS1987

Comets, volcanism, the salt rich regolith and cycling of volatiles on Mars

The composition of the Martian surface and its evolution are examined, reviewing the results of recent theoretical models and composition estimates based on Viking lander analyses. The data are compiled in tables and characterized in detail, and a high degree of variation among the predictions is noted. The discussion centers on the possible roles of comets (as sources of volatiles), the salt rich regolith (as an important water sink), and volcanic activity (interfering with volatile-recycling processes and eventually producing a volatile depleted surface layer).

Clark, Benton C.↗