Soil Test Apparatus for Lunar Surfaces

We have studied several field geotechnical test instruments for their applicability to lunar soil simulants and analog soils. Their performance was evaluated in a series of tests in lunar simulants JSC-1A, NU-LHT-2M, and CHENOBI each prepared in carefully controlled states of compaction through vibration on a shake table with overburden. In general, none of the instruments is adequate for a low-cohesion, frictional soil, but we find that a modified version of a shear vane tester allows us to extract several of the important soil parameters. This modified instrument may be useful for use on the lunar surface by astronauts or a robotic lander. We have also found that JSC-1A does not behave mechanically like the other lunar soil simulants, probably because its particle shapes are more rounded. Furthermore we have studied a soil material, BP-1, identified as very lunar-like at a lunar analog location. We find this material has a natural particle size distribution similar to that of lunar soil and arguably better than JSC-1A. We find that BP-1 behaves very similarly to the high fidelity lunar simulants NU-LHT-2M and CHENOBI.Comment: 15 pages, 14 figures. Presented at Earth & Space 2010 conferenc

Regolith Advanced Surface Systems Operations Robot Excavator

The Regolith Advanced Surface Systems Operations Robot (RASSOR) excavator robot is a teleoperated mobility platform with a space regolith excavation capability. This more compact, lightweight design (<50 kg) has counterrotating bucket drums, which results in a net-zero reaction horizontal force due to the self-cancellation of the symmetrical, equal but opposing, digging forces

Calibration of Cookstove Sensors using Linear Regression

Nearly one billion people of the world’s population lack access to safe drinking water.[1] This has caused severe health problems as well as political and economic problems for many countries. Climate change has made it more difficult to access safe drinking water and is a result of black carbon (BC) and CO2 emissions. [2] The source of these emissions come from a variety of sources; among which are cooking with bio fuels and fossil fuels. Because of the negative effects of cooking, appropriate technologies have been implemented to reduce particulate emissions. However, monitoring of their utilization and effectiveness has not been properly accounted for leading to frequent failures.[3] The Sustainable Water, Energy and Environmental Technologies Laboratory (SWEETLab), at Portland State University (PSU), is developing a method of fixing this problem. The SWEETLab develops and implements technologies for the support of life in remote environments. A key thread of the SWEETLab’s research focuses on improving accountability and methodologies for international development through improved data collection. The goal of the SWEETLab is to proving the sustainability of efficient cookstoves by implementing an in-situ remote monitoring system,( called SWEETSense) a method of which has not been attempted yet until now.[2] Remote Monitoring can provide solutions to many of the issues around sustainability of water treatment, energy and infrastructure intervention in developing communities such as unrealizable survey data and relying on spot checks to assess performance. [2] The SWEETSense is designed to have a low power profile while maintaining high-resolution data logging capabilities. One valuable part of the SWEETSense is temperature sensors, thermistors. The thermistors trigger the SWEETSense to turn on whenever a cookstove is being used. The purpose of having a temperature sensor is to help minimize power consumption and allows high resolution logging of usage event while running off of compact batteries for a targeted minimum of six months.[2] When the SWEETSense is triggered on, CO and CO2 sensors will trigger, recording data as the user is using the efficient cookstove. The overall goal of the SWEETLab is to find an appropriate method of calibrating the SWEETSense. As the SWEETLab progresses forward in mass production, the SWEETSense will require a faster calibration process. For the focus of this project, the temperature sensors of the SWEETSense will be studied. The project goal is to figure out the best process of calibrating the temperature sensors using a calibration bath while maintaining a 3-degree error goal, set at four calibrated temperature ranges; 21.3 °C (ambient), 35°C, 60°C and 80 °C. Over the course of five weeks, variations of calibration tests were performed on the sensors using the calibration water bath however the problem found was that there was a large amount of time spent performing the calibration tests while little progress was made in calibrating the sensors