Achieve Mission Goals Research Articles

Mixed reality architecture in space habitats

Mixed Reality (MR) technologies are rapidly establishing themselves in the space industry. From assisting with assembling the Orion capsule via Augmented Reality (AR) to using highly immersive virtual environments for astronaut training, MR technologies provide a powerful mechanism to alter the perception of the physical world and deliver realistic personalized visual stimuli to users.In this paper, we discuss a novel strategy to utilize MR technologies as a design element to enhance the interior architecture of the space habitat and enrich the inhabitants’ personal experience. We discuss two scenarios that entail long duration missions as well as a customized experience for space tourists in Low Earth Orbit (LEO). We report a series of spacecraft volumetric studies of the ergonomics associated with the application of MR technologies. Physical, Virtual and Combined experiences mapped within the volumes with respect to crew ConOps provide a basis for further analysis and are translated to architectural design requirements that inform criteria for the development of personalized MR-based visualizations.The paper concludes with a discussion of directions for future research and design-based investigations. Compilations of mission-influencing factors such as launch mass and volume reduction per habitat, technology limitations and integration requirements are presented and evaluated by the level of importance for achieving mission goals and objectives.

Novel concept of satellite manoeuvre planning using graph theoretical techniques

Manoeuvrable, responsive satellite constellations that respond to real time events could provide data on demand for time-critical tasks, such as disaster monitoring and relief efforts. The authors demonstrate the feasibility of such a system by expanding on a fully analytical method for designing responsive spacecraft manoeuvres using low thrust propulsion. These manoeuvres are perceived as a graph that enables efficient exploration and optimised selection of favourable routes that achieve mission goals while highlighting resilience and redundancy in the mission’s execution. A case study is presented that considers four satellites required to provide flyovers of two targets, with an associated graph of 10,839 possible manoeuvres. Investigation of the graph highlights that a good, but not minimum time, solution can allow the system to perform well, while also providing greater resilience to changes in mission priorities and errors in execution. This analytical approach enables operators to trade-off between a loss of time by using only one satellite versus the disruption of moving multiple satellites for a potentially faster response. The impact of varying mission capabilities, such as using fewer satellites, smaller swath width or less propellant, can be evaluated by reducing the graph without recalculating manoeuvre options.

Fault Tolerant Guidance of Under-Actuated Satellite Formation Flying Using Inter-Vehicle Coulomb Force

In this study, satellite formation flying guidance in the presence of under actuation using inter-vehicle Coulomb force is investigated. The Coulomb forces are used to stabilize the formation flying mission. For this purpose, the charge of satellites is determined to create appropriate attraction and repulsion and also, to maintain the distance between satellites. Static Coulomb formation of satellites equations including three satellites in triangular form was developed. Furthermore, the charge value of the Coulomb propulsion system required for such formation was obtained. Considering Under actuation of one of the formation satellites, the fault-tolerance approach is proposed for achieving mission goals. Following this approach, in the first step fault-tolerant guidance law is designed. Accordingly, the obtained results show stationary formation. In the next step, tomaintain the formation shape and dimension, a fault-tolerant control law is designed.

Satellite battery sensor values prediction using Bayesian ridge regression models

Proper mission control plays a key role in the lifetime of space mission operation, as it ensures that all resources are efficiently utilized when achieving mission goals. Ground control station operation mainly depends on received telemetry together with models simulating spacecraft`s subsystems. Created models help in raising the level of autonomy of MCC (Mission Control Center). Data driven models describe the actual state of the subsystem in real operation situations rather than theoretical costly physical models. This paper proposes data driven models for satellite battery subsystem based on Bayesian ridge regression algorithm. The ridge coefficients minimize a penalized residual sum of squares Thirty models of all thirty battery variables (capacitance, voltage, pressure and temperature) are built from normal operation data. Sensor reading value can be predicted from an observation of all other 29 values. Faults present in sensors or in system can be detected if predicted values are not equal to actual downloaded data from satellite. Bayesian ridge regression models are validated in terms of slope, intercept, R2-value, Q2 -value P-value and standard error.

Achieving Stability in African Conflicts: The Role of Contingent Size and Force Integrity

Many conflict scholars argue for the salience of large peacekeeping contingents to the success of peacekeeping. The argument for a large force borders on the provision of effective deterrence and containment of spoilers if the need arises to enforce peace. While this paper recognizes the need for robust peace support operations in achieving stability in mission areas, it also extends its focus to the issue of force integrity, which argues for less diversity within contingents. Force integrity facilitates greater bonding among troops and heightens the determination to achieve mission objectives. Using the six peace support operations undertaken by the African Union, the article argues that force integrity enhances a contingent’s ability to achieve mission goals. This article goes beyond the common argument that the mere provision of a large and well-equipped contingent is sufficient for maintaining stability.

High-Level Mission Specification and Planning for Collaborative Unmanned Aircraft Systems Using Delegation

Automated specification, generation and execution of high level missions involving one or more heterogeneous unmanned aircraft systems is in its infancy. Much previous effort has been focused on the development of air vehicle platforms themselves together with the avionics and sensor subsystems that implement basic navigational skills. In order to increase the degree of autonomy in such systems so they can successfully participate in more complex mission scenarios such as those considered in emergency rescue that also include ongoing interactions with human operators, new architectural components and functionalities will be required to aid not only human operators in mission planning, but also the unmanned aircraft systems themselves in the automatic generation, execution and partial verification of mission plans to achieve mission goals. This article proposes a formal framework and architecture based on the unifying concept of delegation that can be used for the automated specification, generation and execution of high-level collaborative missions involving one or more air vehicles platforms and human operators. We describe an agent-based software architecture, a temporal logic-based mission specification language, a distributed temporal planner and a task specification language that when integrated provide a basis for the generation, instantiation and execution of complex collaborative missions on heterogeneous air vehicle systems. A prototype of the framework is operational in a number of autonomous unmanned aircraft systems developed in our research lab.

Development of an autonomous spacecraft for planetary exploration

The purpose of this paper is to present a new approach in the concept and implementation of autonomous micro‐spacecraft. The one true “artificial agent” approach to autonomy requires the micro‐spacecraft to interact in a direct manner with the environment through the use of sensors and actuators. As such, little computational effort is required to implement such an approach, which is clearly of great benefit for limited micro‐satellites. Rather than using complex world models, which have to be updated, the agent is allowed to exploit the dynamics of its environment for cues as to appropriate actions to achieve mission goals. The particular artificial agent implementation used here has been borrowed from studies of biological systems, where it has been used successfully to provide models of motivation and opportunistic behaviour. The so‐called “cue‐deficit” action selection algorithm considers the micro‐spacecraft to be a non‐linear dynamical system with a number of observable states. Using optimal control theory rules are derived which determine which of a finite repertoire of behaviours the satellite should select and perform. The principal benefits of this approach is that the micro‐spacecraft is endowed with self‐sufficiency, defined here to be the ability to achieve mission goals, while never placing itself in an irrecoverable position.

Velocity field path-planning for single and multiple unmanned aerial vehicles

AbstractUnmanned aerial vehicles (UAV) have seen a rapid growth in utilisation for reconnaissance, mostly using single UAVs. However, future utilisation of UAVs for applications such as bistatic synthetic aperture radar and stereoscopic imaging, will require the use of multiple UAVs acting cooperatively to achieve mission goals. In addition, to de-skill the operation of UAVs for certain applications will require the migration of path-planning functions from the ground to the UAV. This paper details a computationally efficient algorithm to enable path-planning for single UAVs and to form and re-form UAV formations with active collision avoidance. The algorithm presented extends classical potential field methods used in other domains for the UAV path-planning problem. It is demonstrated that a range of tasks can be executed autonomously, allowing high level tasking of single and multiple UAVs in formation, with the formation commanded as a single entity.

Normative design of organizations. I. Mission planning

This paper presents a design methodology for synthesizing organizations to execute complex missions efficiently. It focuses on devising mission planning strategies to optimally achieve mission goals while optimally utilizing organization's resources. Effective planning is often the key to successful completion of the mission, and conversely, mission failure can often be traced back to poor planning. Details on subsequent phases of the design process to construct the mission-driven human organizations are discussed in a companion paper.

Ice & Fire: Missions to the most difficult solar system destinations… on a budget

Three radii from the surface of the Sun… more natural radiation around Jupiter than would be encountered immediately following a nuclear war… to the farthest planet and beyond… these challenges are faced by the three “Ice & Fire” missions: Solar Probe, Europa Orbiter, and PlutoKuiper Express. These three missions will be beneficiaries of the X2000 and related advanced technology development programs. Technology developments now in progress make these missions achievable at costs recently thought adequate only for missions of relatively short durations to “nearby” destinations. The next mission to Europa after Galileo will determine whether a global subsurface liquid water ocean is currently present, and will identify locations where the ocean, if it exists, may be most accessible to future missions. Pluto-Kuiper Express will complete the reconnaissance of the known planets in our Solar System with geological, compositional, and atmospheric mapping of Pluto and Charon while Pluto remains relatively near the Sun during its 248 year orbit. An extended mission to a Kuiper Disk object may be possible, depending on remaining sciencecraft resources. Using a unique combination of Sun shield/high gain antenna and quadrature encounter geometry, Solar Probe will deeply penetrate our nearest star's atmosphere to make local measurements of the birth of solar wind, and to remotely image features as small as 60 kilometers across on the Sun's surface. Avionics technology, leading to integration of functions among a set of multichip modules with standard interfaces, will enable lower production costs, lower power and mass, and the ability to package with modest shielding to enable survival in orbit around Europa inside Jupiter's intense radiation belts. The same avionics and software can be utilized on the other Ice & Fire missions. Each mission is characterized by a long cruise to its destination, facilitated by planetary flybys. The flight systems will represent a unique early integration of science “payload” and “spacecraft,” becoming a more integrated “sciencecraft.” To reduce operations and tracking costs, sciencecraft will be more autonomous. They will self-monitor and self-command, while sending a continuous beacon alerting ground receivers to general sciencecraft health and any need for immediate attention. Where solar power proves impractical for achieving mission goals, an advanced radioisotope power source may be utilized with a much smaller amount of fuel than on prior missions. The three missions described are to begin the Outer Planets/Solar Probe exploration program, as first proposed in the FY1998 Federal Budget. Sciencecraft, launch systems and mission operations must all fit within a single program, encouraging system- and program-wide tradeoffs to minimize costs. Some of the system and technological solutions utilized by these missions may find application in a variety of other science-driven missions.