Design of an unmanned, reusable vehicle to de-orbit debris in Earth orbit

The space debris problem is becoming more important because as orbital missions increase, the amount of debris increases. It was the design team's objective to present alternative designs and a problem solution for a deorbiting vehicle that will alleviate the problem by reducing the amount of large debris in earth orbit. The design team was asked to design a reusable, unmanned vehicle to de-orbit debris in earth orbit. The design team will also construct a model to demonstrate the system configuration and key operating features. The alternative designs for the unmanned, reusable vehicle were developed in three stages: selection of project requirements and success criteria, formulation of a specification list, and the creation of alternatives that would satisfy the standards set forth by the design team and their sponsor. The design team selected a Chain and Bar Shot method for deorbiting debris in earth orbit. The De-orbiting Vehicle (DOV) uses the NASA Orbital Maneuvering Vehicle (OMV) as the propulsion and command modules with the deorbiting module attached to the front

Sunmaster: An SEP cargo vehicle for Mars missions

Options are examined for an unmanned solar powered electric propulsion cargo vehicle for Mars missions. The 6 prime areas of study include: trajectory, propulsion system, power system, supporting structure, control system, and launch consideration. Optimization of the low thrust trajectory resulted in a total round trip mission time just under 4 years. The argon propelled electrostatic ion thruster system consists of seventeen 5 N engines and uses a specific impulse of 10,300 secs. At Earth, the system uses 13 engines to produce 60 N of thrust; at Mars, five engines are used, producing 25 N thrust. The thrust of the craft is varied between 60 N at Earth and 24 N at Mars due to reduced solar power available. Solar power is collected by a Fresnel lens concentrator system using a multistacked cell. This system provides 3.5 MW to the propulsion system after losses. Control and positioning to the craft are provided by a system of three double gimballed control moment gyros. Four shuttle 'C' launches will be used to transport the unassembled vehicle in modular units to low Earth orbit where it will be assembled using the Mobile Transporter of the Space Station Freedom

キューブサットバスシステムのための標準化・適応性インターフェース設計

Since the 2000s, small satellite launches have increased rapidly each year and the number of players in this field is strongly linked to the popularity of the CubeSat standard around the globe. Highlights of its achievements are often the compatibility of launches via a standardized deployer (i.e. POD), shorter development times and lower costs than conventional large satellites. CubeSats are not just popular instruments for educating students in space research and engineering, but also enable us to demonstrate challenging technologies in a cheaper and quicker way and carry out scientific research in the field. But the success of CubeSat\u27s mission often fails. Improvements in reliability and prevent poor workmanship are necessary. The CubeSat standard enabled the small satellite market to expand enormously. In fact, a modular spacecraft deployer which can be attached to many different launch vehicles as a secondary payload was the key technology for the CubeSat Standard. To date, only external CubeSat interfaces, especially the mechanical interface, have been standardized. CubeSat needs a standardized internal interface to take advantage of the modularity. It will contribute to cost reduction and development time. One key to cutting costs and delivery time is a standardized internal interface for different CubeSat missions. In three CubeSat projects at the Kyushu Institute of Technology in Kyutech, a backplane interface approach, proposed as UWE-3 by the University of Würzburg in Germany, has been implemented to reduce the time for development and assembly. The backplane approach also helped to reduce the risk of harnessing faults. In order to satisfy the mission requirements, however, modifications to the proposed standard interface board were necessary for each CubeSat project. The thesis proposes a new idea of a Software-Configurable Bus Interface (SoftCIB) with a backplane board to obtain more flexibility, particularly for data connections. Instead of hardware routing, a Complex Programmable Logical Device (CPLD) was used to reprogram the bus interface on the PCB. The following advantages will be offered by the standardized backplane interface board: (1) less harness, (2) ease of assembly and disassembly (3) compatible with different CubeSat projects and (4) flexible for routings. We can use the SoftCIB again to reduce the cost and development of the interface boards, rather than designing and making new interface boards for new CubeSat projects. Various projects have various payloads for missions and interface requirements. The high flexibility of SoftCIB\u27s interface allows one to select either the same or a different subsystem board such as an OBC or EPS. A functional test with a breadboard module validated the concept. A radiation test has shown that the selected CPLD is strong enough to maintain total ionization doses in low Earth orbit of more than 2 years. The system level verification has been carried out in the engineering model of the BIRDS-3 project at Kyutech.九州工業大学博士学位論文 学位記番号：工博甲第485号 学位授与年月日：令和元年9月20日1. Introduction|2. Background|3. Implementation of Backplane approach for CubeSats|4. Purposed interface – The SoftCIB|5. Testing campaign|6. On-orbit demonstration|7. Conclusions九州工業大学令和元年

Search based software engineering: Trends, techniques and applications

© ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version is available from the link below.In the past five years there has been a dramatic increase in work on Search-Based Software Engineering (SBSE), an approach to Software Engineering (SE) in which Search-Based Optimization (SBO) algorithms are used to address problems in SE. SBSE has been applied to problems throughout the SE lifecycle, from requirements and project planning to maintenance and reengineering. The approach is attractive because it offers a suite of adaptive automated and semiautomated solutions in situations typified by large complex problem spaces with multiple competing and conflicting objectives. This article provides a review and classification of literature on SBSE. The work identifies research trends and relationships between the techniques applied and the applications to which they have been applied and highlights gaps in the literature and avenues for further research.EPSRC and E

Architectural disruption in aerospace

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 70-71).Distinctive technology and customer / supplier relationships are currently the primary sources of competitive advantage in the Aerospace industry. Modular Open System Architecture (MOSA) requirements represent a significant disruption to this mode of competition. The United States Department of Defense intends to accelerate the rate of aerospace innovation and inject additional competitiveness into the procurement process through the modularization of its products and effective intellectual property management. This combination of architectural disruption and new customer capabilities has the potential to reduce the industry's opportunity to capture value from innovative technologies or a position as first supplier. Historical examples such as Polaroid and IBM demonstrate the organizational paralysis that often results from disruptions in product architecture. The competitive formula becomes ingrained in the processes, resources, and culture of mature companies and is no longer explicit knowledge, which limits the company's ability to develop the capabilities required to compete in its new environment. Competing in a MOSA environment will require the development of new organizational capabilities such as rapid experimentation, fighting standards wars, and protecting system-level knowledge. Defining the disruptive threat and the foundations of current core competencies will enable firms to develop the organizational capabilities essential for this shift in competitive context.(cont.) The author will present several historical examples of architectural disruption, a framework for evaluating the disruptive change, and an identification of organizational anchors that may hinder a particular competitor's ability to respond to MOSA. The goal of the thesis is to start a dialogue within an identified incumbent with in hopes of beginning the organizational transformation required to effectively compete in this new era.by Geoffrey Ashworth.S.M

BCAUS Project description and consideration of separation of data and control

The commonly stated truths that data may be segregated from program control in generic expert system shells and that such tools support straightforward knowledge representation were examined. The ideal of separation of data from program control in expert systems is difficult to realize for a variety of reasons. One approach to achieving this goal is to integrate hybrid collections of specialized shells and tools instead of producing custom systems built with a single all purpose expert system tool. Aspects of these issues are examined in the context of a specific diagnostic expert system application, the Backup Control Mode Analysis and Utility System (BCAUS), being developed for the Gamma Ray Observatory (GRO) spacecraft. The project and the knowledge gained in working on the project are described

Electronically steerable millimeter wave antenna techniques for space shuttle applications

A large multi-function antenna aperture and related components are described which will perform electronic steering of one or more beams for two of the three applications envisioned: (1) communications, (2) radar, and (3) radiometry. The array consists of a 6-meter folded antenna that fits into two pallets. The communications frequencies are 20 and 30 GHz, while the radar is to operate at 13.9 GHz. Weight, prime power, and volumes are given parametrically; antenna designs, electronics configurations, and mechanical design were studied