Preliminary results of geologic and remote sensing studies of Rima Mozart

In order to better understand the processes responsible for the formation of lunar sinuous rilles, a study of Rima Mozart was conducted using a variety of geologic, photographic, and remote sensing data. The apparent source of this rille is located in a highlands unit of known composition and it is hypothesized that thermal and mechanical erosion played an important role in the formation of Rima Mozart. Excellent photographic, topographic, multispectral, and radar data exist for this rille. The preliminary results of an analysis of this data are presented. Photographic data indicates the presence of two volcanic source vents for Rima Mozart: Kathleen and Ann. It is suggested that Rima Mozart, like many other lunar sinuous rilles, was most likely formed by a combination of events. Rima Mozart does follow a pre-existing, dominant NW/SE structural trend suggesting the influence of structural features on the rille, however, the tectonic influence is not the sole source for the formation of the rille, as suggested by the presence of the two source vents and the spatter around Ann. It is suggested that the rille formation began with an explosive eruption at Kathleen which later calmed down to a pulsating, high volume, low-viscosity lava flow. The rapid effusion rate of the magma as well as its high temperature and turbid nature helped carve the sinuous rille into the fractured and structurally weak Apennine Bench Formation underneath. Similar eruptions and subsequent flows were also created at Ann and joined to the main channel by a NE-trending secondary rille

Lunar and Hawaiian lava tubes: Analogs and uses based on terrestrial field data

Presented here is an analysis of the data collected for a large number of Hawaiian lava tubes on the islands of Oahu, Molokai, and Hawaii. The results are extrapolated to lunar conditions. It is argued that lava tubes that formed on the Earth and the Moon are relatively stable over time, as illustrated by the ridigity of the Hawaiian prehistoric lava tubes as well as the historic tubes located in the bombing range near Mauna Loa. These natural structures should be considered for use in planning for the expansion and advanced stages of the future manned lunar base

Energy and low-income tropical housing in Tanzania

Low-income housing in Tanzania is traditionally made from mud and thatch. With thatch having a typical life span of 2-7 years and mangrove poles 5-15 years, low durability is identified as the key issue with the traditional low-income house design. This paper studies the financial and social implications, embodied energy (EE) and human energy (HE) of a variety of materials in a bid to identify both the positive and negative impacts of each material substitution on the overall design, the environment and the local community. Using primary data collected from houses in the Mbweni district of Dar es Salaam and The Inventory of Carbon and Energy to calculate EE, a qualitative and quantitative assessment of each material is made. 47% of residents questioned in Tanzania, identified low durability to be the key issue with their mud house, with design changes which address this issue therefore affecting the largest share of the population. Stabilised bricks are identified as the key material substitution that should be adopted by local people, they perform well in terms of improved durability, financial and environmental considerations, and have the potential to be socially beneficial as well. This research identifies the social considerations to be key to understanding how local people will respond to the suggested material substitutions and whether they are likely to be adopted in the future. Whilst the environmental considerations are important, this is not a concept local people can relate to and does not affect their day-to-day lives as much as financial and social implications. It is extremely difficult and ethically questionable, especially in communities with people living close to poverty, to expect someone to adopt a design which requires more effort/money on their part, just because it is better for the environment

On using a pyroclastic deposit as a manned lunar base site

Hawke et al. (1990) suggest that ilmenite found in Apollo 17-type pyroclastic glass may provide feedstock for the hydrogen reduction of ilmenite process for producing lunar oxygen. They also suggest that the ilmenite may help retain solar wind hydrogen and helium which can be extracted for use at a lunar outpost or even transported back to Earth for fusion fuel in the case of helium-3. Therefore, they suggest that ilmenite-rich material may be the best candidate. Here, researchers propose a somewhat different approach. They propose that the pyroclastic glass can be reduced directly to produce oxygen and one or more metals. Sulfur would be another important byproduct of the processing. This process would eliminate the need for having specific minerals such as ilmenite or for doing any mineral concentration. The bulk pyroclastic would provide the feedstock. Some recent experiments at the Johnson Space Center suggest that an iron-rich composition would be the most suitable for this direct feedstock reduction and that the titanium content may not be important. Also, the lunar pyroclastic deposits would be extremely useful in constructing and supporting a lunar base

A search for intact lava tubes on the Moon: Possible lunar base habitats

We have surveyed lunar sinuous rilles and other volcanic features in an effort to locate intact lava tubes that could be used to house an advanced lunar base. Criteria were established for identifying intact tube segments. Sixty-seven tube candidates within 20 rilles were identified on the lunar nearside. The rilles, located in four mare regions, varied in size and sinuosity. We identified four rilles that exhibited particularly strong evidence for the existence of intact lava tube segments. These are located in the following areas: (1) south of Gruithuisen K, (2) in the Marius Hills region, (3) in the southeastern Mare Serenitatis, and (4) in the eastern Mare Serenitatis. We rated each of the 67 probable tube segments for lunar base suitability based on its dimensions, stability, location, and access to lunar resources. Nine tube segments associated with three separate rilles are considered prime candidates for use as part of an advanced lunar base

An investigation into the methods for modelling pre-existing cracks in phase field problems

Phase field (PF) models are an increasingly popular method of numerically modelling fracture problems. While research has focused on the practical applications and computational efficiency of PF methods, little discussion exists around the merits of different methods of prescribing initial cracks in PF fracture problems. This paper presents a comparison of three methods for modelling pre-existing cracks, through Dirichlet-type PF boundary conditions, an initial strain history term, and through physical discontinuities in the mesh. The comparison is made using the load-displacement responses for a common tensile benchmark fracture problem