Crater Formation Due to Lunar Plume Impingement

Thruster plume impingement on a surface comprised of small, loose particles may cause blast ejecta to be spread over a large area and possibly cause damage to the vehicle. For this reason it is important to study the effects of plume impingement and crater formation on surfaces like those found on the moon. Lunar soil, also known as regolith, is made up of fine granular particles on the order of 100 microns.i Whenever a vehicle lifts-off from such a surface, the exhaust plume from the main engine will cause the formation of a crater. This crater formation may cause laterally ejected mass to be deflected and possibly damage the vehicle. This study is a first attempt at analyzing the dynamics of crater formation due to thruster exhaust plume impingement during liftoff from the moon. Though soil erosion on the lunar surface is not considered, this study aims at examining the evolution of the shear stress along the lunar surface as the engine fires. The location of the regions of high shear stress will determine where the crater begins to form and will lend insight into how big the crater will be. This information will help determine the probability that something will strike the vehicle. The final sections of this report discuss a novel method for studying this problem that uses a volume of fluid (VOF)ii method to track the movement of both the exhaust plume and the eroding surface

Experimental Validation of Star CCM+ for Liquid Container Slosh Dynamics

No abstract availabl

Passive Thermal Coating Observatory Operating in Low-Earth Orbit (PATCOOL) Cubesat Design to Test Passive Thermal Coatings in Space

The PATCOOL is a NASA sponsored, University of Florida developed 3U Cu-beSat meant to investigate the feasibility of using a cryogenic selective surface coating as a new, more efficient way of passively cooling components in space. Initial tests on the ground demonstrate that this coating should provide a much higher reflectance of the Suns irradiant power than any existing coating, while still providing far-infrared power emission. The ultimate validation of this tech-nology requires on-orbit testing. PATCOOL hosts a 4-sample housing, with the samples shaped as thin cylinders (coin-like). Two samples are coated with state-of-the-art material, while the other pair uses the new coating to be evaluated. The temperatures of all samples during the mission (minimum 72 hours of data col-lection) are measured via thermistors. The samples are connected via thin Kevlar strings to the housing, to minimize heat transfer. The housing is designed to shield the samples from Earths thermal radiation, and the CubeSat is attitude stabilized and controlled via a gravity gradient boom, magnetorquers and a reaction wheel set. Thermal Desktop simulations show PATCOOLs ability to thermally isolate the samples from heat exchanges other than with Sun and deep space, thanks to its thermal design and the chosen attitude profile

PAssive Thermal Coating Observatory Operating in Low Earth Orbit (PATCOOL)

The PATCOOL is a NASA sponsored, University of Florida developed 3U CubeSat meant to investigate the feasibility of using a cryogenic selective surface coating as a new, more efficient way of passively cooling components in space. Initial tests on the ground demonstrate that this coating should provide a much higher reflectance of the Sun's irradiant power than any existing coating, while still providing far-infrared power emission. The ultimate validation of this technology requires on-orbit testing. PATCOOL hosts a 4-sample housing, with the samples shaped as thin cylinders (coin-like). Two samples are coated with state-of-the-art material, while the other pair uses the new coating to be evaluated. The temperatures of all samples during the mission (minimum 72 hours of data collection) are measured via thermistors. The samples are connected via thin Kevlar strings to the housing, to minimize heat transfer. The housing is designed to shield the samples from Earth's thermal radiation, and the CubeSat is attitude stabilized and controlled via a gravity gradient boom, magnetorquers and a reaction wheel set. Thermal Desktop simulations show PATCOOL's ability to thermally isolate the samples from heat exchanges other than with Sun and deep space, thanks to its thermal design and the chosen attitude profil

Using CFD Techniques to Predict Slosh Force Frequency and Damping Rate

Resonant effects and energy dissipation due to sloshing fuel inside propellant tanks are problems that arise in the initial design of any spacecraft or launch vehicle. A faster and more reliable method for calculating these effects during the design stages is needed. Using Computational Fluid Dynamics (CFD) techniques, a model of these fuel tanks can be created and used to predict important parameters such as resonant slosh frequency and damping rate. This initial study addresses the case of free surface slosh. Future studies will focus on creating models for tanks fitted with propellant management devices (PMD) such as diaphragms and baffles

Ethnobioconservation with a Predict, Observe, Explain (POE) Strategy Against Student Cooperative Skills

Student cooperative skills are an internal representation of the conceptual understanding of Maluku's natural resource conservation biology. Currently, students still have difficulty explaining the relationship between biological conservation and biological, physical and chemical conditions of a natural resource phenomenon, at a concrete level. These difficulties require research, through Predict, Observe, Explain (POE) Strategy, Ethnobioconservation Development of Maluku Natural Resources. This study aimed to reveal the development and differences in students' cooperative skills after learning Bioconservation with POE and conventional learning. Indicators of students' cooperative skills were adapted from Johnson, & Holubec, (2002). The topic of Maluku Natural Resources Ethnobioconservation combined with the POE Strategy consists of five topics, namely 1) Burning rocks in Maluku Tenggara Barat Indonesia; 2) Sasi Lompa Opening Ceremony in Haruku Village, Maluku Indonesia; 3) Timba Laor, Latuhalat Village, Ambon Maluku Indonesia; 4) Meti Kei Ceremony in Southeast Maluku Indonesia; and 5) The Opening Ceremony of Sasi Teripang in Noloth Village, Saparua Island, Maluku Indonesia. The findings indicated that the POE strategy resulted in better student cooperative skills. The N-Gain scores of students in the class using the POE and conventional strategies were found to be 71.43 and 47.73, respectively. Meanwhile, the value of coopetarif skills was higher (36.67%) compared to conventional learning. Thus, it can be concluded that POE Strategy learning is effective in increasing the cooperative skills of students. This research recommends that POE is very important and useful for use in biology learning. because the POE strategy facilitates student concept chang

Zonasi Daerah Rawan Gempa Bumi di Kecamatan Pundong, Bantul Berdasarkan Pendekatan Geomorfolog

ABSTRAK Gempabumi 27 Mei 2006 mengakibatkan kerusakan berat pada bangunan di Kecamatan Pundong, Kabupaten Bantul, Yogyakarta. Kerusakan bangunan yang diakibatkan oleh gempabumi bervariasi di setiap bentuklahan. Penelitian ini menggunakan pendekatan geomorfologi dengan satuan bentuklahan sebagai unit analisis. Hasil penelitian menunjukkan bahwa karakteristik bentuklahan dapat menjadi indikator tingkat kerusakan bangunan akibat gempabumi. Aspek-aspek geomorfologi memiliki tingkat pengaruh yang berbeda di suatu daerah dan pengaruh aspek-aspek geomorfologi tersebut membentuk suatu zona rmvan gempabumi di Kecamatan Pundong. Zona kerawanan tinggi terhadap gempabumi berada pada kelompok bentuklahan Dataran Fluvio-VulkanikMerapi Muda. Zona kerawanan sedang terhadap gempabumi terdapat pada bentuklahan Lereng Kaki Koluvial Material Lava, Breksi, dan Tuf Zona kerawanan rendah terhadap gempabumi terletak pada lereng tengah dan lereng atas perbukitan struktural di sebelah timur Kecamatan Pundong.ABSTRACT The earthquake May 27, 2006 caused severe damage on buildings in Pundong District, Bantul Regency, Yogyakarta. Earthquake-induced buildings damage vary at each landform. This research is using geomOlphological approach with landform unit as an analysis unit. The result shows that landform characteristics can be an indicator level of earthquakeinduced buildings damage. The geomorphological aspects has levels of induce in a certain area and the induce of geomorphological aspectsformed a certain earthquake prone zone in Pundong District. The high prone zone is located at the group of landforms Fluvio-Volcanic Young Merapi Plain. The moderate prone zone is located at Colluvial Footslope consist of breccias, lava, and tuff. The slight prone zone is located in the middle and upper slope of structural hills in the east part of Pundong District

DIVERSITY PHENETICS OF TYPES SEAGRASS IN VILLAGE POKA BEACH MALUKU BASED ON MORPHOMETRICS

This research aims to determine the phenetic diversity of seagrass species in the coastal waters of Poka Village based on morphometrics. This research is a type of descriptive research, in which morphometric measurements are carried out to determine the phenetic diversity of seagrass species. Meanwhile, for kinship relationships between seagrasses. Software is used past 4.0. The results of this research were that four types of seagrass were found, namely Thalasssia hemprichii, Enhalus acoroides, Halophila pinifolia and Halophila ovalis. This indicates that the Poka Village beach has a high phenetic diversity of seagrass species with varying morphometrics for each character and type, which is influenced by the type of substrate and environmental parameters. Seagrasses that are closely related, namely, Thalasssia hemprichii and Enhalus acoroides are in one monophyletic group (ingroup) and are very closely related. Likewise with Halodule pinifolia and Halophila ovalis

NASA, Rockets, and the International Space Station

General overview of NASA, Launch Services Program, and the Slosh experiment aboard the International Space Station. This presentation is designed to be presented in front of university level students in hopes of inspiring them to go into STEM careers