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The objective of this report is to discover a skyhook’s ability to change the plane of another spacecraft’s orbit while ensuring that each vehicle’s orbital energy remains constant. Skyhooks are a proposed momentum exchange device in which a tether is attached to a counterweight at one end and at the

The objective of this report is to discover a skyhook’s ability to change the plane of another spacecraft’s orbit while ensuring that each vehicle’s orbital energy remains constant. Skyhooks are a proposed momentum exchange device in which a tether is attached to a counterweight at one end and at the other, a capturing device intended to intercept rendezvousing spacecraft. Trigonometric velocity vector relations, along with objective comparisons to traditionally proposed uses for skyhooks and gravity-assist maneuvers were responsible for the ultimate parameterization of the proposed energy neutral maneuver. From this methodology, it was determined that a spacecraft’s initial relative velocity vector must be perpendicular to, and rotated about the skyhook’s total velocity vector if it is to benefit from an energy neutral plane change maneuver. A quaternion was used to model the rotation of the incoming spacecraft’s relative velocity vector. The potential post-maneuver spacecraft orbits vary in their inclinations depending on the ratio between the skyhook and spacecraft’s total velocities at the point of rendezvous as defined by the parameter called the alpha criterion. For many cases, the proposed maneuver will serve as a desirable alternative to currently practiced propulsive plane change methods because it does not costly require a substantial amount of propellant. The proposed maneuver is also more accessible than alternative methods that involve gravity-assist and aerodynamic forces. Additionally, by avoiding orbital degradation through the achievement of unchanging total orbital energy, the skyhook will be able to continually and self-sustainably provide plane changes to any spacecraft that belong to orbits that abide by the identified parameters.

ContributorsSeale, Ryan (Author) / Peet, Matthew (Thesis director) / Dahm, Werner (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
Description

This report summarizes the development of a test stand used to measure the thrust or impulse of pulsed plasma thrusters (PPT). Currently, there is a lack of accessible, cost-efficient methods for measuring thrust in the market due to the difficulties associated with developing a test stand for extremely low thrust

This report summarizes the development of a test stand used to measure the thrust or impulse of pulsed plasma thrusters (PPT). Currently, there is a lack of accessible, cost-efficient methods for measuring thrust in the market due to the difficulties associated with developing a test stand for extremely low thrust outputs. Despite the difficulties, there is an ever-growing need to develop new methods of measuring thrust as the increased demand for small satellites has prompted investors from the government and private sectors to conduct further research into the development of better propulsion systems for space applications. A part of the developmental process of making propulsion systems is being able to test the thrust of these propulsion systems under vacuum conditions that simulate a space environment. This report details the research conducted on existing test stands as well as the process of designing, manufacturing, and testing a thrust measurement device.

ContributorsYu, Finley (Author) / Goryll, Michael (Thesis director) / Sharp, Thomas (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2024-05
Description

When rover mission planners are laying out the path for their rover, they use a combination of stereo images and statistical and geological data in order to plot a course for the vehicle to follow for its mission. However, there is a lack of detailed images of the lunar surface

When rover mission planners are laying out the path for their rover, they use a combination of stereo images and statistical and geological data in order to plot a course for the vehicle to follow for its mission. However, there is a lack of detailed images of the lunar surface that indicate the specific presence of hazards, such as craters, and the creation of such crater maps is time-consuming. There is also little known about how varying lighting conditions caused by the changing solar incidence angle affects perception as well. This paper addresses this issue by investigating how varying the incidence angle of the sun affects how well the human and AI can detect craters. It will also see how AI can accelerate the crater-mapping process, and how well it performs relative to a human annotating crater maps by hand. To accomplish this, several sets of images of the lunar surface were taken with varying incidence angles for the same spot and were annotated both by hand and by an AI. The results are observed, and then the AI performance was rated by calculating its resulting precision and recall, considering the human annotations as being the ground truth. It was found that there seems to be a maximum incidence angle for which detect rates are the highest, and that, at the moment, the AI’s detection of craters is poor, but it can be improved. With this, it can inform future and more expansive investigations into how lighting can affect the perception of hazards to rovers, as well as the role AI can play in creating these crater maps.

ContributorsHayashi, Brent Keopele (Author) / Das, Jnaneshwar (Thesis director) / Mahanti, Prasun (Committee member) / Anand, Harish (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
A robotic exploration mission that would enter a lunar pit to characterize the environment is described. A hopping mechanism for the robot's mobility is proposed. Various methods of hopping drawn from research literature are discussed in detail. The feasibilities of mechanical, electric, fluid, and combustive methods are analyzed. Computer simulations

A robotic exploration mission that would enter a lunar pit to characterize the environment is described. A hopping mechanism for the robot's mobility is proposed. Various methods of hopping drawn from research literature are discussed in detail. The feasibilities of mechanical, electric, fluid, and combustive methods are analyzed. Computer simulations show the mitigation of the risk of complex autonomous navigation systems. A mechanical hopping mechanism is designed to hop in Earth gravity and carry a payload half its mass. A physical experiment is completed and proves a need for further refinement of the prototype design. Future work is suggested to continue exploring hopping as a mobility method for the lunar robot.
ContributorsMcKinney, Tyler James (Author) / Thangavelautham, Jekan (Thesis director) / Robinson, Mark (Committee member) / Asphaug, Erik (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
This paper studies the history and development of ion propulsion systems and survey past, present, and developing technology with their applications to space missions. This analysis addresses the physical design parameters and process that is a part of designing and optimizing a gridded ion thruster. It also identifies operational limits

This paper studies the history and development of ion propulsion systems and survey past, present, and developing technology with their applications to space missions. This analysis addresses the physical design parameters and process that is a part of designing and optimizing a gridded ion thruster. It also identifies operational limits that may be associated with solar-powered ion propulsion systems and posits plausible solutions or alternatives to remedy such limitations. These topics are presented with the intent of reviewing how ion propulsion technology evolved in its journey to develop to today's systems, and to facilitate thought and discussion on where further development of ion propulsion systems can be directed.
ContributorsTang, Justine (Author) / White, Daniel (Thesis director) / Dahm, Werner (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Emission Spectroscopy is a powerful tool for the identification of mineralogical samples and has been used for decades in labs to study the geology of Earth and Mars. However, the instruments needed to make these measurements are large, expensive and sensitive pieces of equipment that are too cumbersome to use

Emission Spectroscopy is a powerful tool for the identification of mineralogical samples and has been used for decades in labs to study the geology of Earth and Mars. However, the instruments needed to make these measurements are large, expensive and sensitive pieces of equipment that are too cumbersome to use in the field. There are some commercial products that attempt to work in the field, however they perform this task poorly, often resulting in limited applications, poor performance or not being truly portable. My thesis utilizes the TES family of planetary instruments as a source of inspiration for creating a truly portable Fourier Transform InfraRed spectrometer. From this initial design phase, it appears that it is possible to build an instrument with vastly improved capabilities over the current systems on the market. This roughly 12 inch by 7 inch by 8 inch device with a 3-inch diameter telescope is capable of achieving a SNR of over 1000 during a 5 minute scan of a sample allowing for 5 sigma (99.99994% Confidence) identification of 1% spectral features from 5 um to >60 um making this instrument a one of a kind device with high application potential, not only for field geologist but for the future of manned exploration of space. Currently an accurate measurement of costs is not available, however with more development and optimization a total cost of around $50K is feasible while still maintaining the same performance characteristics. If the costs can fall within an acceptable range, this device will not only be technically impressible but viable from a financial standpoint as well.
ContributorsFagan, Ryan Alexander (Author) / Christensen, Phil (Thesis director) / Ruff, Steve (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The emergence of the space industry facilitated new technologies which completely changed how humans live. However, the industry itself has also acted as a constant source of conflict between its participants. As a result, the industry has encountered issues regarding the role of private industry in space development, the militarization

The emergence of the space industry facilitated new technologies which completely changed how humans live. However, the industry itself has also acted as a constant source of conflict between its participants. As a result, the industry has encountered issues regarding the role of private industry in space development, the militarization of space, how to address the gap in space technology between developed and underdeveloped nations, and the overall economic climate of space. With these numerous challenges facing the space industry, this investigation hopes to present potential solutions to said issues while providing a baseline for future research. In order to accomplish this, the international relations ideologies of neorealism, neoliberalism and constructivism were applied in conjunction with opinions from multiple industry scholars to synthesize potential solutions and provide a knowledge baseline and methodology for future investigations. This resulted in the conclusion that, in the scope of this investigation, a constructivist solution focusing on human nature's role in international relations is the best means of avoiding global conflict while promoting prosperity. The proposed constructivist solution proposes the development of multi-actor groups which defend, maintain and develop space assets collectively. These groups formed around ideological similarities would effectively limit conflict and increase the viability of space. However, this constructivist approach is not satisfactory due to its complexity which could result in the breakdown of peace and prosperity if interdependence between actors cannot be maintained. As a result, more research is necessary to develop an appropriate solution but, the methodology, information and understanding of different international relations principles used in this thesis can be used in future investigations to develop more comprehensive solutions.
ContributorsDeininger, Nicholas Robert (Author) / Foy, Joseph P. (Thesis director) / White, Daniel (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
It is becoming increasingly necessary for orbiting mission vehicles to rendezvous with target satellites in or near geosynchronous equatorial orbit (GEO), for example to perform on-orbit inspection, servicing, or refueling, or for various types of military proximity operations. The rendezvous of the mission vehicle with the target often must be initiated on short

It is becoming increasingly necessary for orbiting mission vehicles to rendezvous with target satellites in or near geosynchronous equatorial orbit (GEO), for example to perform on-orbit inspection, servicing, or refueling, or for various types of military proximity operations. The rendezvous of the mission vehicle with the target often must be initiated on short notice and achieved quickly. The total rendezvous time and the propellant consumed in performing the rendezvous are the two main considerations in choosing an optimal waiting orbit and transfer trajectory for the mission vehicle. Propellant-efficient transfer options include a Hohmann transfer or bi-elliptic transfer, though faster but less efficient transfers can also be considered. The waiting orbit for the mission vehicle can be chosen anywhere from LEO to GEO, though waiting orbits above GEO can also be considered, and both prograde and retrograde orbits can be considered. The chosen waiting orbit determines the time between successive rendezvous opportunities and the required orbit transfer time, as well as the amount of propellant needed to perform the rendezvous. The relative importance assigned to reducing propellant consumption versus reducing the rendezvous time depends on the mission. Therefore, this project conducts an in-depth Keplerian analysis of such mission-optimized waiting orbits and transfer trajectories for GEO target rendezvous, and will determine the optimal configuration for any given relative emphasis on reducing the rendezvous time versus reducing propellant consumption.
ContributorsLewis, Megan (Author) / Dahm, Werner (Thesis director) / Middleton, Jim (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2025-05