Aerocapture offers a near propellantless and quick method of orbit insertion at atmosphere bearing planetary destinations. Compared to conventional propulsive insertion, the primary advantage of using aerocapture is the savings in propellant mass which could be used to accommodate more useful payload. To protect the spacecraft from the aerodynamic heating during the maneuver, the spacecraft must be enclosed in a protective aeroshell or deployable drag device which also provides aerodynamic control authority to target the desired conditions at atmospheric exit. For inner planets such as Mars and Venus, aerocapture offers a very attractive option for inserting small satellites or constellations into very low circular orbits such as those used for imaging or radar observations. The large amount of propellant required for orbit insertion at outer planets such as Uranus and Neptune severely limits the useful payload mass that can delivered to orbit as well as the achievable flight time. For outer planet missions, aerocapture opens up an entirely new class of short time of flight trajectories which are infeasible with propulsive insertion. A systems framework for rapid conceptual design of aerocapture missions considering the interdependencies between various elements such as interplanetary trajectory and vehicle control performance for aerocapture is presented. The framework provides a step-by-step procedure to formulate an aerocapture mission starting from a set of mission objectives. At the core of the framework is the ``aerocapture feasibility chart", a graphical method to visualize the various constraints arising from control authority requirement, peak deceleration, stagnation-point peak heat rate, and total heat load as a function of vehicle aerodynamic performance and interplanetary arrival conditions. Aerocapture feasibility charts have been compiled for all atmosphere-bearing Solar System destinations for both lift and drag modulation control techniques. The framework is illustrated by its application to conceptual design of a Venus small satellite mission and a Flagship-class Neptune mission using heritage blunt-body aeroshells. The framework is implemented in the Aerocapture Mission Analysis Tool (AMAT), a free and open-source Python package, to enable scientists and mission designers perform rapid conceptual design of aerocapture missions. AMAT can also be used for rapid Entry, Descent, and Landing (EDL) studies for atmospheric probes and landers at any atmosphere-bearing destination.

The aim of this work is to test the ability of three selected theoretical approaches to explain the response of the Czech Republic to the American offer to build the ABM radar device on the Czech soil. These theories are: neorealism, utilitarian liberalism and constructivism. Each of these approaches looks at the social reality from a different perspective which allows us to view the issue in its complexity and diversity. Each theory also uses a different set of independent variables to explain the behavior of the Czech government in this case (these variables are: autonomy and influence for neorealism; domestic interests for liberalism and international and domestic norms for constructivism). Thanks to this variety of variables we are enabled to critically evaluate which key factors played the crucial role in the Czech decision-making process in this particular issue and possibly also to point out some assumed regularities which might play an important role in forming of the Czech security policy as such. The main task of the first chapter is to provide some broader historical and political context of the case. Next three chapters are then dedicated to testing of the theories by comparing their deductively phrased hypothesis with the value of dependent variable, which for our work is represented...

Master thesis analyzes strategic behavior of the PRC in the region of the Northeast Asia in direct relationship with regional missile defense. The aim is to analyze motives of China`s regional strategic behavior with respect to the specific technological element (= Theatre Missile Defense) on the basis of predetermined analytical levels: realistic, liberal and constructivist. But there are great differences in technological configuration of individual missile defense systems or in the configuration of the relationship of regional actors with the PRC. Thus the thesis will comprise of case studies analyzing the complex relationship of the PRC and regional actors (that are creating regional missile defense). The creation of regional missile defense can endanger China`s vital strategic interests (in the region of Northeast Asia) under specific conditions. But the regional strategic behaviour of the PRC is moderate. The aim is to explain, why the PRC does not change its regional strategic behavior in direct connection with emerging theater missile defence.

The diploma thesis "Strategic Defense Initiative" deals with the issue of the Strategic initiative on the basis of historical-political analysis. The SDI was a crucial topic during the 80s, which had political impacts on the development of the international events and the Cold war in general. This work presents brief history of the United States ABM systems and introduced historical context. Furthermore, the author analyzes possible reasons for the SDI announcement and reexamines Reagan's speech from March 1983. Persons and interest groups who were promoting strategic defense are also included in this analysis. Problems connected to the SDI and its brief description are also mentioned. The following chapter deals with Soviet reaction to the SDI. The seventh chapter dicusses the European reaction to the SDI. The topic is analyzed on the example of United Kingdom. Next chapter deals with the Anti Ballistic Missile treaty and its interpretations from the SDI prespective. Last chapter discusses US - Soviet summits which took place in the 80s with emphasis on the SDI.

Modern-day terrorist attacks present a considerable danger for commercial aircrafts. This thesis analyzes potential methods of such attacks with a critical analysis of the most dangerous type: an attack from the outside of the aircraft via a fragmentation missile warhead. Such missiles cause damage to the airframe of the aircraft through fragments created by the explosion. In this thesis, analytical geometry is used to determine the area of the aircraft affected by the fragmentation. The aircraft’s geometry and the fragments’ dispersion are calculated by analytical functions, and the effect of the damage is analyzed. A shooting experiment was also carried out, in which fragments were shot at a reinforced skin panel that was manufactured according to the real design of commercial aircraft. The results of the experiment revealed that only directly hit sections of the structure are damaged. Data obtained by the experiment was then used for the creation and improvement of the model used in the simulation by means of the finite element method. This model is used for the numerical calculation of the damage sustained. Further included in the thesis is an analysis of the change in the load-bearing capacity after such an attack. The relationship between the size of the damage and its effect on the load-bearing capacity of the component as well as the entire structure is defined. First, the effect of component damage is analyzed via the FMEA/FMECA methods. This analysis is then extended using fuzzy logic. Fuzzy logic analysis is based on the determination of the size of the damaged component area and the component’s importance on the structure’s carry loads. Application of the defined approach is described for several parts of an aircraft’s life cycle, including development, operation after the terrorist attack, and assessment of causes after a crash caused by a fragmentation missile warhead.

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No description available.

<p>As the small satellite market has grown from a niche of the space economy to a full commercial force,  microthrusters remain an area of significant growth in the space industry as new technologies mature. The \textit{Film-Evaporation Microelectricalmechanical Tunable Array} (FEMTA) is one such device. FEMTA is \textit{microelectricalmechanical system} (MEMS) device that harnesses the microcapillary action of water and vacuum boiling to generate thrust. The water propellant is not chemically altered at all by the process; it is simply evaporated. This technology has been tested in relevant laboratory environments, and a suborbital flight opportunity in 2023 as a payload on a Blue Origin New Shepard rocket  will grant FEMTA a demonstration in a space environment. The flight will provide 150 seconds of weightlessness at the zenith of the suborbital flight path before the booster returns to land. During weightlessness, the experiment will be exposed to the ambient environment allowing for a full capability test of the thruster. The experiment is meant to demonstrate the propellant management system for FEMTA in 0G and measure the thrust produced by a FEMTA thruster.</p> <p><br></p> <p>The propellant management system portion of the experiment consists of an oversized version of the subsystem intended for use in the thruster. The propellant management system uses a hydrofluoroether to inflate a diaphragm to ensure constant wetting of the propellant tank exit and nozzle inlet. The experiment will take tank pressure data and flow sensor data to understand the system's behavior. The system is duplicated for redundancy and to double the possible data. This system requires further testing before being prepared for launch, vibrational testing, thermal testing, and vacuum testing. </p> <p><br></p> <p>The 0G thrust experiment and plume analysis portion of the experiment consists of numerical modeling and a novel thrust measurement approach. \textit{Direct Simulation Monte Carlo} (DSMC) is being applied to understand the pressure, density, and temperature distributions of the plume of water vapor produced by the FEMTA thruster. The FEMTA nozzle environment is challenging to simulate with computational fluid dynamics  or DSMC due to chaotic transient effects and because both the continuum and molecular regimes must be considered. The current analysis consisted of a two-dimensional model and investigated the effect of meniscus location and contact angle on thrust generated.</p> <p><br></p> <p>It is not possible to use traditional thrust measurement devices (sensitive torsional thrust stands or microsensors intended for use on small satellites) for microthrusters on a rocket booster. Two  novel approaches for performing thrust measurement in the range of 100 microNewtons have been investigated. The first approach ionizes the FEMTA thruster plume and analyzes the plasma by optical emission spectroscopy. The theory states that the relative intensity of a given wavelength observed correlates to the density of the species in the plasma. The density of water would be directly correlated to the thrust generated by FEMTA during the experiment, as more water is evaporated as thrust is increased. This method is no longer being considered for the suborbital experiment but did yield promising results. </p> <p><br></p> <p>The second approach employs a d'Arsonval meter, a photo-interrupt, and an Arduino controller. The d'Arsonval meter consists of a stationary permanent magnet with a moving coil and a pointer. Increasing the voltage in the coil causes a torque on the system due to the magnetic field induced by the permanent magnet. This torque causes a deflection of the pointer that is proportional to the voltage applied. The flag of the sensor will be placed in the path of the gas jet from the thruster. The force caused by the jet pressure will move the flag. An Arduino controller will vary the voltage to hold the flag in place. As the mass flow rate increases, the reaction force required to hold the flag in place will increase. This sensor can be calibrated using an analog cold gas system that passes various gases (air nitrogen, argon, etc.) through an orifice nozzle at mass flow rates that are set by a mass flow rate controller. DSMC analysis has been performed to understand the flow field and flow properties and how they directly relate to the force experienced by the flag sensor. </p> <p>An undergraduate course has supported parts of the work described in this dissertation. This course has applied the Vertically Integrated Projects approach to project-based learning. This method and its results were analyzed and lessons learned as well as a blueprint for future application of this method to other small satellite projects are discussed.</p>

Den ökade tekniska utvecklingen och användandet av obemannade system ställer krav på en förståelse för dess inverkan på krigföringen. Urban miljö är ofta oundviklig vid markstrid och medför utmaningar som korta stridsavstånd, ökad risk för vådabekämpning och snabba stridsförlopp. Ett system som patrullrobot kan bidra till förbandens förmågor genom spaning, verkan och möjlighet till flexibel manövrering. Arbetet besvarar frågeställningen ”Hur kan patrullrobotsystem medföra militär nytta vid ett markförbands anfall i bebyggelse?” med utgångspunkt i den teoretiska referensramen militär nytta. Analysverktygen utgörs av SWOT-analyser och teorins dimensioner för militär effektivitet, militär lämplighet samt överkomlig kostnad. Syftet med arbetet är att utforska hur patrullrobotsystem kan medföra militär nytta vid anfall mot hastigt uppkomna mål. Resultatet visade att patrullrobotsystem kan anses ha flera möjligheter till att medföra militär nytta. Anledningen är främst de karaktäristiska egenskaperna gällande dess sensorer och en inbyggd verkansdel som bidrar till möjlighet för spaning och precisionsbekämpning. Det tekniska systemet har således en god övergripande förmåga att utföra uppdrag i urban miljö genom exempelvis ökad underrättelseinhämtning och reducerad risk för sidoskador. Patrullrobotsystemet tyder även ha en god förmåga att kunna interageras med andra system och bidra till en synergieffekt. Vidare är den ekonomiska faktorn oftast lägre i jämförelse med andra vapensystem som har liknande precision vid långa avstånd. Likt andra militära system är det dock av vikt att användandet övervägs och är i enlighet med de lagar, förordningar och etiska principer som är fastställda. Tydliga målsättningar underlättar ett optimerat användande av systemet. / The increased technological development and the use of unmanned systems are requiring an understanding of their impact on warfare. Urban environments are often unavoidable in ground combat and bring challenges such as short combat distances, increased risk of friendly fire and rapid combat progress. A system such as a loitering munition can contribute to the unit's abilities through reconnaissance, damage and the possibility of flexible maneuvering. This thesis report answers the question "How can loitering munition systems entail military utility in the context of a ground unit's attack in urban warfare?" based on the theoretical frame of military utility. The analysis tools consist of SWOT analysis and the theory's dimensions of military effectiveness, military suitability and affordability. The purpose is to explore how loitering munition systems can entail military utility in attacks against rapidly emerging targets. The result showed that loitering munition systems can be considered to have several opportunities to entail military utility. The reason is mainly the characteristic features regarding its sensors and a built-in warhead that contributes to the possibility of reconnaissance and precision strike. Thus, the technical system has a comprehensive ability to carry out missions in an urban environment through, for instance, increased intelligence and reduced risk of collateral damage. The loitering munition system also indicates a great ability to interact with other systems and contributes to a synergy effect. Furthermore, the economic factor is usually lower in comparison to other weapon systems with equivalent precision throughout long distances. Nonetheless, as for other military systems, it is important that the use is considered and is in accordance with the laws, regulations and ethical principles that have been established. Clear objectives make it easier to optimize the use of the system.

I och med den ryska invasionen av Ukraina har Försvarsmakten identifierat behovet av en ökad pansarvärnsförmåga. Detta har lett till prov och försök av ett nytt pansarvärnsrobotsystem. Införandet av ett nytt vapensystem med nya egenskaper är en utmaning. När detta vapensystem är en pansarvärnsrobot vars förmåga inom markstridande förband har varit nedprioriterade i flera år, kan införandet ta tid. Arbetet generera underlag för att belysa de tekniska och doktrinära skillnaderna mellan Robot 58 och befintliga pansarvärnsrobotsystem som brukas i Försvarsmakten. Arbetets tillvägagångssätt var en intervjustudie där fyra individer intervjuades. Dokumentär forskning genomfördes för att komplettera och utvidga den data som samlats in från intervjuerna. De fyra olika pansarvärnsrobotsystemen egenskaper och prestanda analyserades genom en SWOT-analys. Analysen belystes ur Försvarsmaktens grundläggande förmågor, specifikt rörlighet och verkan. Resultatet av analysen visar att även fast systemen är ämnade för samma syfte, är Robot 58 väsentligt mer utvecklad och påvisar varför den tillhör generation fyra till skillnad från de andra robotsystemen. Robot 58 nya egenskaper, däribland indirekt eldgivning, kommer vapensystemet att bidra starkt till den tredimensionella striden för infanteriförbanden och utgöra ett stort hot mot motståndarens mekaniserade förmåga. Det som krävs är att chefer på lägre förbandsnivåer övar med förmågorna Robot 58 har att erbjuda. / Due to the Russian invasion of Ukraine, the Swedish Armed Forces have identified the need for an increased anti-tank capability. This has led to the test and trial of a new anti-tank missile. The introduction of a new weapon system with new characteristics can be a challenge. When this weapon system is an anti-tank missile which capabilities in ground combat units have been down prioritized for several years, the implementation can take time. The purpose of this paper was to generate data to highlight the technical and doctrinal differences between rbs 58 and existing anti-tank missiles used by the Swedish Armed Forces. The approach of the work was an interview study where four individuals were interviewed. Documentary research was conducted to complement the data collected from the interviews. The characteristics and performance of the four different anti-tank missile systems were analyzed with a SWOT analysis. The analysis was highlighted from the perspective of the Swedish Armed Forces' basic operational capabilities, specifically mobility and effectiveness. The result of the analysis showed that even though the systems are intended for the same purpose, rbs 58 is significantly more developed and demonstrates why it is considered to belong as a generation four missile unlike the other anti-tank missile. Rbs 58 new characteristics, including indirect fire mode, will greatly contribute to the three-dimensional battle for infantry units and pose a major threat to the opponent's mechanized units. The requirement is that officers at lower unit levels practice with the capabilities rbs 58 has to offer.