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As of now, only about 4% of apparent space has been explored. The spacecraft used to explore these areas of the unknown have to go through a design process that often does not include conditions on environmental factors. The technical project is designing a mini spacecraft, called a CubeSat, that will reconfigure into a reentry vehicle at hypersonic speeds named the Hypersonic reEntry Deployable Glider Experiment (HEDGE). The purpose of this project is to successfully collect and transmit temperature and pressure while the spacecraft is reentering the Earth’s atmosphere at hypersonic speeds. The STS research discusses the environmental effects that are caused from space exploration. The environmental effects are both directly and indirectly resulting from space mission’s successes and failures. The technical and STS research are tightly coupled as HEDGE will be a space mission that can cause environmental harm. For this stage of the technical project, the goal was to reach the critical design review phase by the end of the semester. All of the design components have been chosen to meet all the design requirements and rationale is provided to prove that the mission will succeed safely. With a successful critical design review, the project can move forward to full scale prototyping. In order to have a successful critical design review, the project got separated into six teams, each focussing on a specific subsystem. Each team was tasked with researching the best possible components and design for this mission while remaining within a mass, and cost budget. Each team also had to verify that these selected components and design would lead to a successful mission. As a result, the critical design review has been completed as a proposal suitable for NASA. This proposal describes the design choices and is a request for funding for the full scale implementation of HEDGE. Each team included their major subsystem components, rationale for choosing the parts, calculations to back up the rationale, and how their subsystem will be assembled. The STS research question examined was how continued space exploration has caused environmental issues. In order to research this question, effects of rocket emissions, reentry heating, and space debris were explored. Additionally, possible fuel alternatives were researched to reduce rocket emission harm. Furthermore, Pinch and Bjiker’s Social Construction of Technology framework was adapted to provide a potential design process to mitigate the environmental risks with space missions. In the STS thesis, one of the main topics discussed is the production of space debris from failed space missions. Space debris is constantly orbiting in close proximity with the Earth, and even pieces the size of a paint fleck can cause considerable damage to a satellite in space. This can result in a continuous rapid increase in space debris which could lead to a higher amount of space debris reentering the atmosphere which then releases harmful toxins that lead to global warming. Additionally, black carbon released from rockets has a longer effect than other vehicles’ production because rockets burn fuel higher in the atmosphere which makes the particles last much longer. Some alternatives to rocket emissions are under development, including a bacteria based fuel and a fuel created by using recycled plastics. The technical project will be ready to begin its full scale prototyping next academic year with the guidance of this year's critical design review. However, future students working on this project should focus on environmental factors surrounding this future mission, especially harm caused by the rocket used to put the CubeSat into space, and the reentry effects when the vehicle burns up in the atmosphere. Similar to the Social Construction of Technology framework used in the STS report, the future team for the technical report could follow that framework.

The design of optimal guidance law for intercepting a near-space hypersonic maneuvering target with bounded inputs is considered. Firstly, a maneuvering model for near-space hypersonic aircraft is given. Then, the aircraft acceleration prediction can be obtained using this model with two neural networks. By using the target acceleration prediction, which is taken into account when calculating the Zero Effort Miss (ZEM), an optimal sliding-mode guidance law is proposed to fulfill the guidance task. An adaptive sliding-mode switch term is designed to deal with actuator saturation and prediction errors. Finally, numerical simulations show that the proposed guidance law can reduce the energy consumption and the terminal acceleration command of the interceptor effectively.

Recent molecular-beam experiments of high-velocity atomic oxygen (O), atomic nitrogen (N), and molecular oxygen (O2) impacting carbon material at high temperature produced detailed surface chemistr...

Optimal performance is extremely important for hypersonic flight control. Different from the most existing methodologies which only consider basic control performance including stability, robustness and transient performance, this article deals with the design of nearly optimal tracking controllers for hypersonic flight vehicles (HFVs). Firstly, main controllers are developed for the velocity subsystem and the altitude subsystem of HFVs via concise fuzzy approximations. Then, optimal controllers are nearly implemented utilizing single-network adaptive critic design. Moreover, the stability of closed-loop systems and the convergence of optimal controllers are theoretically proved. Finally, compared simulation results are given to verify the superiority. The special contribution is the application of low-complex control structure owing to the critic-only network and advanced learning laws developed for fuzzy approximations, which is expected to guarantee satisfied real-time performance.

The solid-fueled Scramjet is an interesting option for supersonic combustion ramjet. It shows significant advantages such as simple fuel supply and compactness, avoiding the complex system of tanks and pipelines that encountered in liquid-fueled Scramjets. The solid-fueled Scramjet could be the simplest air-breathing engine for the hypersonic flight regime. This paper presents a comprehensive and systematic review of the research progress on solid-fueled Scramjet in various institutes and universities. It summarizes a progress overview of three types of the solid-fueled Scramjet, which covers a wealth of landmark numerical and experimental results. Based on this, several relevant key technologies are proposed. Several inherent scientific issues are refined, such as the mixing mechanism of multi-phase flow and supersonic airflow, ignition and combustion mechanism of the condensed phase in a supersonic airflow, and coupling mechanism of gas and solid phase in a supersonic flow. Finally, the historical development trend is clarified, and some recommendations are provided for future solid-fueled Scramjet.

Among flourishing control studies on air-breathing hypersonic vehicles (AHVs), actuator characteristics have not been fully accommodated. This study gives a comprehensive consideration to physical ...

Shock tube experiments are a cornerstone of investigations into the hypersonic flight environment. However, the actual flow through the basic shock tube has not been well characterized in the literature, and nonuniformities arising in the test gases are not well understood. This work produces a quasi-one-dimensional analytical methodology for predicting the nonuniformities in the postshock test gas based exclusively on the experimentally measured history of shock speed down the tube. Wave effects extracted from shock speed variations are shown to provide all information necessary in order to reconstruct the test slug from any particular experiment. Accurate representation of flow dynamics is initially checked against argon test cases following accelerating and decelerating shock trajectories, each with a tube-end Mach number of 6.5 and a fill pressure of 66.66 Pa in a tube of 100 mm diameter. Agreement between the method and results from a viscous, axisymmetric Navier–Stokes solution is found to be within 1% in pressure and temperature.

This thesis portfolio aims to provide clarity into modern spaceflight by examining the design of a hypersonic glider and detailing the evolution of the spaceflight industry in the United States. Though both the technical report and the thesis deal with modern spaceflight, the technical report focuses on the design and deployment of a specific instance of current spaceflight technology, while the thesis analyzes the role of society in shaping human spaceflight technology through shifting political, economic, and social climates. Hypersonic flight data is notoriously difficult to acquire, in addition to be unreliable. The technical project was pursued to assess the feasibility of using CubeSats as hypersonic test vehicles. The technical report provides a mission overview, mission architecture and concept, conceptual design, schedule, and cost for a CubeSat designed to glide and collect flight data at hypersonic speeds in the upper atmosphere. A strong measure of feasibility is whether the CubeSat is able to collect data well, and how costly the vehicle is; for this project, the upper limit on total cost was $67,722. An additional objective of the project was to facilitate the learning and development of future engineers in the University of Virginia undergraduate Mechanical and Aerospace Engineering program. The thesis analyzes the evolution of the human spaceflight industry in the 21st century, and, more specifically, how advocates of human spaceflight have furthered their agendas. To understand this, it delves into the beginnings of the major participants in the industry, including the National Aeronautics and Space Administration, the United States Department of Defense, and private firms like SpaceX. This is done within the Social Construction of Technology framework, which emphasizes the interactions between diverse participants as catalysts for technological development. These participants and their values, interests, problems, and solutions are discussed. The analysis finds that the decentralization of the space industry has allowed for exponential growth in human spaceflight capability, but will present new problems as societies advance into the future.

The technical portion of the thesis aimed to answer the following question: how can a hypersonic glider flight experiment fit in a CubeSat platform? Hypersonic flight occurs at speeds exceeding five time the speed of sound and is an expanding research field in the aerospace industry with military and civil applications. Military applications include hypersonic missiles, both offensive and defensive, and high-speed aircraft. Civil applications include access to space and commercial air travel. A CubeSat is a small satellite flown in low earth orbit that is well suited for undergraduate education. Hypersonic glider flight experiments are difficult to replicate in wind tunnels and expensive to achieve on rockets and aircrafts. By using a CubeSat, university students are able to conduct these experiments at a lower cost, and with greater accessibility. The STS research portion of the thesis is aimed to answer the following question: how are space enterprises striving to make commercial human spaceflight more accessible? Human spaceflight became a reality as a result of the Space Race between the United States and Soviet Union during the Cold War. This competition to achieve the best spaceflight capacity skyrocketed the ability for private companies to develop their own space industry. Through researching different space enterprises' motivations for sending more humans to space, three main goals were identified: scientific research, exploration and colonization, and space tourism. The paper looks at what different American commercial space companies are doing to send more humans to space specifically for those goals. The Social Construction of Technology (SCOT) STS framework was used to show how society's desire to pursue each of these goals results in commercial space companies developing new technologies. The discussion section outlines how the three goals identified all ultimately work together and it is argued that each goal will be achieved more quickly if they are all pursued at the same time by different companies as opposed to all space enterprises focusing on one of those goals at a time. Both the technical and STS topics connect together by answering the following general research question: how can outer space be reached by more people? The technical project shows how university students can realistically work on a project that will one day be sent into space. The STS portion shows how much the human spaceflight industry is expanding. It identifies how private companies are striving to send more humans to space along with their different motivations behind this goal. In order to carry out the technical portion, the team developed a conceptual design review for their proposed CubeSat hypersonic glider flight experiment. The team utilized the Space Mission Engineering process of going from broad mission objectives or a vague concept to an operational mission. The team developed primary and secondary objectives, identified the mission architecture, outlined the mission concept, developed functional and operational requirements and system constraints, proposed a tentative schedule for the construction and fabrication of the design, and estimated the total cost of the mission. The team consisted of 15 aerospace and mechanical undergraduates. The members were divided into six sub teams: Project Management, Communications, Software and Avionics, Power, Thermal and Environment, Attitude Determination and Control Systems (ADACS) and Orbits, and Structures and Integration. The project manager oversaw the mission and made sure the technical sub teams were supported and on track. The five technical sub teams each developed subsystem level requirements and focused on their specific aspects of the CubeSat design. The final design consisted of a 3U CubeSat with hinges that allows it to transform into a cone-cube shape when re-entering the atmosphere to prolong hypersonic flight. The final technical report was in the form of a proposal to the National Aeronautics and Space Administration (NASA) and the Department of Defense (DOD) for funding to carry out the rest of the project.

With the development of hypersonic vehicles, considerable attention has been paid to thermal protection systems (TPSs). Among the different types of TPS, integrated TPS (ITPS) has attracted...

Waverider is expected to break the lift-to-drag ratio constraint in the hypersonic flight condition and it is commonly been studied as the forebody of the cruise vehicle. In this paper, we developed an approach to make waverider as the airframe for the air-breathing cruise vehicle. The fuselage that designed based on the cone-derived waverider theory with a unique upper boundary curve generates the same conical shock wave as that generated by the conical nose of the vehicle. Therefore, the vehicle is expected to have a full-body wave-ride performance and suitable for cruising in the hypersonic condition. Also, a gap between the conical nose and the fuselage is designed to be the inlet of the air-breathing engine. In comparison with the traditional cone-derived waverider, this kind of configuration has additional volume so that it can afford enough space for installing the engine system in the airframe. The performance of this kind of configuration is validated by the numerical method in the design Mach number. With the engineering estimation approach used to calculate the aerodynamic performance of the vehicle in hypersonic conditions, we studied the influence of design parameters on the aerodynamic performance. Results show that the increase of the design Mach number does negative impact on the lift-to-drag ratio but positive impact on the volumetric efficiency while the increase of the design direction angle has an opposite influence. However, in comparison with the response of the lift-to-drag ratio, the volumetric efficiency is less affected by the dihedral angle, which means that the dihedral angle can control the aerodynamic performance effectively within a limited volumetric efficiency range.