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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Canadian Advanced Nanospace eXperiment 7 (CanX-7) Mission Analysis, Payload Design and Testing

Shmuel, Barbara 26 November 2012 (has links)
A deorbiting drag device is being designed and built by the University of Toronto Institute for Aerospace Studies/Space Flight Laboratory (UTIAS/SFL) to be demonstrated on the Canadian Advanced Nanospace eXperiment 7 (CanX-7) satellite. CanX-7 will address the growing issue of space debris by designing a drag sail device that will be demonstrated for cubesat-sized satellites. Mission analysis done to ensure the drag device functions properly and deorbits within the required lifetime is performed while varying different properties such as drag coefficient, effective drag area, and solar cycle variations. The design evolution of the device is documented and the chosen design, along with several stages of prototyping, is described. The individual components that make up the device are described as are preliminary numerical analyzes. Finally, the test plan required for the device is described with several deployment experiments and risk reduction tests documented.
2

Canadian Advanced Nanospace eXperiment 7 (CanX-7) Mission Analysis, Payload Design and Testing

Shmuel, Barbara 26 November 2012 (has links)
A deorbiting drag device is being designed and built by the University of Toronto Institute for Aerospace Studies/Space Flight Laboratory (UTIAS/SFL) to be demonstrated on the Canadian Advanced Nanospace eXperiment 7 (CanX-7) satellite. CanX-7 will address the growing issue of space debris by designing a drag sail device that will be demonstrated for cubesat-sized satellites. Mission analysis done to ensure the drag device functions properly and deorbits within the required lifetime is performed while varying different properties such as drag coefficient, effective drag area, and solar cycle variations. The design evolution of the device is documented and the chosen design, along with several stages of prototyping, is described. The individual components that make up the device are described as are preliminary numerical analyzes. Finally, the test plan required for the device is described with several deployment experiments and risk reduction tests documented.
3

Attitude Dependent De-orbit Lifetime Analysis of an Aerodynamic Drag Sail Demonstration Spacecraft and Detailed Thermal Subsystem Design for a Polar Orbiting Communications Nanosatellite

Tarantini, Vincent 27 November 2012 (has links)
Contributions to two missions are presented. The first is a demonstration mission called CanX-7 that uses a 4 square metre drag sail to de-orbit a 3.5 kg satellite. In order to estimate the effectiveness of the drag sail, a novel method is developed that takes into account the time-varying nature of the projected drag area. The Space Flight Laboratory designed drag sail is shown to be sufficient to de-orbit the CanX-7 spacecraft within the 25 year requirement. The Antarctic Broadband demonstrator spacecraft is a 20 cm cubical nanosatellite that will demonstrate the feasibility of a Ka-band link between the research community in Antarctica and stakeholders in Australia. In support of this mission, a passive thermal control subsystem is designed that will keep all the components within their operational temperature limits at all times throughout the mission.
4

Attitude Dependent De-orbit Lifetime Analysis of an Aerodynamic Drag Sail Demonstration Spacecraft and Detailed Thermal Subsystem Design for a Polar Orbiting Communications Nanosatellite

Tarantini, Vincent 27 November 2012 (has links)
Contributions to two missions are presented. The first is a demonstration mission called CanX-7 that uses a 4 square metre drag sail to de-orbit a 3.5 kg satellite. In order to estimate the effectiveness of the drag sail, a novel method is developed that takes into account the time-varying nature of the projected drag area. The Space Flight Laboratory designed drag sail is shown to be sufficient to de-orbit the CanX-7 spacecraft within the 25 year requirement. The Antarctic Broadband demonstrator spacecraft is a 20 cm cubical nanosatellite that will demonstrate the feasibility of a Ka-band link between the research community in Antarctica and stakeholders in Australia. In support of this mission, a passive thermal control subsystem is designed that will keep all the components within their operational temperature limits at all times throughout the mission.
5

Passive Disposal of Launch Vehicle Stages in Geostationary Transfer Orbits Leveraging Small Satellite Technologies

Galles, Marc Alexander 01 June 2021 (has links) (PDF)
Once a satellite has completed its operational period, it must be removed responsibly in order to reduce the risk of impacting other missions. Geostationary Transfer Orbits (GTOs) offer unique challenges when considering disposal of spacecraft, as high eccentricity and orbital energy give rise to unique challenges for spacecraft designers. By leveraging small satellite research and integration techniques, a deployable drag sail module was analyzed that can shorten the expected orbit time of launch vehicle stages in GTO. A tool was developed to efficiently model spacecraft trajectories over long periods of time, which allowed for analysis of an object’s expected lifetime after its operational period had concluded. Material limitations on drag sail sizing and performance were also analyzed in order to conclude whether or not a system with the required orbital performance is feasible. It was determined that the sail materials and configuration is capable of surviving the expected GTO environment, and that a 49 m2 drag sail is capable of sufficiently shortening the amount of time that the space vehicles will remain in space.
6

Analysis of Passive Attitude Stabilisation and Deorbiting of Satellites in Low Earth Orbit

Hawe, Benjamin January 2016 (has links)
Orbital debris poses a serious threat to ongoing operations in space.  Recognising this threat, the European Commission has funded the three-year Technology for Self Removal (TeSeR) project with the goal of developing a standard scalable Post Mission Disposal (PMD) module to remove satellites from orbit following the completion of their mission.  As the project coordinator and key member of the TeSeR Project, Airbus Defence and Space Germany will invest significant resources in achieving this goal over the course of the project. This thesis details the initial analysis of potential PMD module designs conducted by the author during an internship within the AOCS/GNC department of Airbus Defence and Space Friedrichshafen between 1 April 2016 and 31 August 2016.  Three main concepts, drag sails, drag balloons and Electrodynamic Tethers (EDTs), were evaluated during this time with an emphasis on determining the ability of each design to permit passive attitude stabilisation of the satellite during PMD.  Following the required modification of a pre-existing MATLAB/Simulink model, several key findings were made for each device concept.  It was found that no drag sail designs investigated permitted passive aerodynamic attitude stabilisation at orbit heights above 550 km.  When deorbiting from 800 km, however, the lack of the desired and stable attitude was not found to have a significant increase on the deorbit time or the area‑time product. Drag balloon designs were predicted to be comparatively unstable and less mass efficient for deorbiting purposes, with area‑time products up to approximately 50 per cent higher than the equivalent mass drag sail designs.  In spite of this, unstable drag balloons were found to provide shorter deorbit times than stable balloons due to the contribution of the satellite body and solar array to the total frontal area of the satellite.  This indicated that attitude stabilisation is not required for satellites equipped with drag balloon devices. Modelling of bare EDTs suggested that tethers with lengths of 1000 metres or more would not permit passive attitude stabilisation at an orbit height of 800 km.  Simulation of a 500 metre EDT, however, indicated that passive attitude stabilisation can be achieved with EDT devices and proved that EDTs can generate significantly higher drag forces than aerodynamic devices while possessing a significantly lower device mass.  Following the analysis of these results, a recommendation was made for future work to be aimed at improving the EDT model used in this investigation.

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