Conceptual design of an on-board optical processor with components

The specification of components for a spacecraft on-board optical processor was investigated. A space oriented application of optical data processing and the investigation of certain aspects of optical correlators were examined. The investigation confirmed that real-time optical processing has made significant advances over the past few years, but that there are still critical components which will require further development for use in an on-board optical processor. The devices evaluated were the coherent light valve, the readout optical modulator, the liquid crystal modulator, and the image forming light modulator

A study to analyze six band multispectral images and fabricate a Fourier transform detector

An automatic Fourier transform diffraction pattern sampling system, used to investigate techniques for forestry classification of six band multispectral aerial photography is presented. Photographs and diagrams of the design, development and fabrication of a hybrid optical-digital Fourier transform detector are shown. The detector was designed around a concentric ring fiber optic array. This array was formed from many optical fibers which were sorted into concentric rings about a single fiber. All the fibers in each ring were collected into a bundle and terminated into a single photodetector. An optical/digital interface unit consisting of a high level multiplexer, and an analog-to-digital amplifier was also constructed and is described

Complex permittivity measurements of lunar samples at microwave and millimeter wavelengths

The relative dielectric constant and loss tangent of lunar sample 14163,164 (fine dust) were determined as a function of density at 9.375, 24, 35, and 60 GHz. In addition, such measurements have also been performed on lunar sample 14310,74 (solid rock) at 9.375 GHz. The loss tangent was found to be frequency independent at these test frequencies and had a value of 0.015 for the lunar dust sample

Project Selection and Process Plan Design for Alternative IME 143/144 Final Project

Hundreds of students each year enroll in IME 143 or IME 144, freshman-level machining classes, and complete an air motor to demonstrate the skills they have acquired on a variety of manufacturing processes. The air motor, however is useful only as a teaching tool in the classroom; once the students bring them home, the air motor becomes little more than a trophy at best. With the capabilities of the machining lab, a final project can be developed that can have a benefit to people in need while maintaining educational value. This project details a process plan for a manual water pump. The pump can be donated for use in developing countries where access to clean water is still in desperate need. The process for manufacturing the water pump had to be deconstructed into specific machining processes and balanced appropriately between the machines available to the classes. The machining lab has a number of different machines that enable students to use 14 different processes. Unlike a production environment, all processes have to be used and balanced to make use of lab time. This often meant using sub-optimal processes and/or procedures. The critical benchmark for implementing the water pump into the curriculum is the cost. Students in IME 143/144 pay lab fees, which cover the cost of materials for the quarter. The fees are $10 for IME 143 and$50 for IME 144. Based on rough estimates from these lab fees, the actual cost of the air motor is between $10 and$20. As designed currently, the water pump has a material cost of about $30. However, this project is larger and more complex. It is recommended that one pump be made for every two students bringing the per student cost to about$15, within the cost range of the air motor

Dynamic modelling to predict the likelihood of plant species persisting in fragmented landscapes in the face of climate change

Many species are threatened by global climate change, but plants are particularly vulnerable because, as sessile organisms, they are unable to move to areas with more suitable conditions as the climate changes. Instead they must rely on their seeds dispersing far and often to keep pace with a changing climate. This problem is exacerbated by the fragmentation of natural landscapes by clearing for agricultural or urban development, or similarly by a species requirement for particular soil types or topography. Models can help predict how different species will be affected by climate change. Most previous modelling work on predicting the persistence of plant and other species under climate change has been static, regression style modelling, known as climate envelope modelling. This has focussed on predicting where suitable environments for a species will likely occur under possible future climatic conditions, based on the species’ distribution under current conditions. While the existence of suitable environments in a new climate is a necessary condition for a species’ persistence, for sessile organisms such as plants, the ability of a species to move and colonise these suitable environments is also likely to be a major limitation. There is therefore a need for models that account for the dynamic processes involved in plant species’ migration and colonisation in changing climates. This paper presents such a dynamic model, called PPunCC (Plant Persistence under Climate Change). We describe how the PPunCC model represents the important factors and processes likely to affect a plant species’ capacity to migrate across a landscape fast enough to keep pace with a changing climate, such as the rate of climate change, the degree of landscape fragmentation, and the plant species’ life history, seed production, dispersal, and establishment. We also discuss how the model could be used to inform management decisions regarding adaptation options such as assisted migration or the creation of large-scale corridors that increase the connectivity of fragmented landscapes in order to help species migrate naturally and find suitable environments in new climates

Space Deterrence: The Delicate Balance of Risk

The United States has created a military structure that is heavily satellite-dependent, without making corresponding improvements in the survivability of its space systems. The result is a classic opportunity for asymmetric, preemptive attack. The central question of this study is how to structure a strategy of deterrence to persuade potentially hostile actors that the costs of attack will nevertheless outweigh the benefits

Dietary Acid Load and Bone Turnover During Long-Duration Spaceflight and Bed Rest

Background Bed rest studies document that a lower dietary acid load is associated with lower bone resorption. Objective We tested the effect of dietary acid load on bone metabolism during spaceflight. Design Controlled 4-d diets with a high or low animal proteinto-potassium (APro:K) ratio (High and Low diets, respectively) were given to 17 astronauts before and during spaceflight. Each astronaut had 1 High and 1 Low diet session before flight and 2 High and 2 Low sessions during flight, in addition to a 4-d session around flight day 30 (FD30), when crew members were to consume their typical in-flight intake. At the end of each session, blood and urine samples were collected. Calcium, total protein, energy, and sodium were maintained in each crew member's preflight and in-flight controlled diets. Results Relative to preflight values, N-telopeptide (NTX) and urinary calcium were higher during flight, and bone-specific alkaline phosphatase (BSAP) was higher toward the end of flight. The High and Low diets did not affect NTX, BSAP, or urinary calcium. Dietary sulfur and age were significantly associated with changes in NTX. Dietary sodium and flight day were significantly associated with urinary calcium during flight. The net endogenous acid production (NEAP) estimated from the typical dietary intake at FD30 was associated with loss of bone mineral content in the lumbar spine after the mission. The results were compared with data from a 70-d bed rest study, in which control (but not exercising) subjects APro:K was associated with higher NTX during bed rest. Conclusions Long-term lowering of NEAP by increasing vegetable and fruit intake may protect against changes in loss of bone mineral content during spaceflight when adequate calcium is consumed, particularly if resistive exercise is not being performed. This trial was registered at clinicaltrials.gov as NCT01713634

Dietary and Urinary Sulfur can Predict Changes in Bone Metabolism During Space Flight

Mitigating space flight-induced bone loss is critical for space exploration, and diet can play a major role in this effort. Previous ground-based studies provide evidence that dietary composition can influence bone resorption during bed rest. In this study we examined the role of dietary intake patterns as one factor that can influence bone mineral loss in astronauts during space flight. Crew members were asked to consume, for 4 days at a time, prescribed menus with either a low (0.3-0.6 g/mEq) or high (1.0-1.3 g/mEq) ratio of animal protein to potassium (APro:K). Menus were developed for each crewmember, and were designed to meet both crew preferences and study constraints. Intakes of energy, total protein, calcium, and sodium were held relatively constant between the two diets. The order of the menus was randomized, and crews completed each set (low and high) once before and twice during space flight, for a total of 6 controlled diet sessions. One inflight session and three postflight sessions (R+30, R+180, R+365) monitored typical dietary intake. As of this writing, data are available from 14 crew members. The final three subjects' inflight samples are awaiting return from the International Space Station via Space-X. On the last day of each of the 4-d controlled diet sessions, 24-h urine samples were collected, along with a fasting blood sample on the morning of the 5th day. Preliminary analyses show that urinary excretion of sulfate (normalized to lean body mass) is a significant predictor of urinary n-telopeptide (NTX). Dietary sulfate (normalized to lean body mass) is also a significant predictor of urinary NTX. The results from this study, will be important to better understand diet and bone interrelationships during space flight as well as on Earth. This study was funded by the Human Health Countermeasures Element of the NASA Human Research Program