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2015 | Buch

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Spacecraft Operations

herausgegeben von: Thomas Uhlig, Florian Sellmaier, Michael Schmidhuber

Verlag: Springer Vienna

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

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Über dieses Buch

The book describes the basic concepts of spaceflight operations, for both, human and unmanned missions. The basic subsystems of a space vehicle are explained in dedicated chapters, the relationship of spacecraft design and the very unique space environment are laid out. Flight dynamics are taught as well as ground segment requirements. Mission operations are divided into preparation including management aspects, execution and planning. Deep space missions and space robotic operations are included as special cases. The book is based on a course held at the German Space Operation Center (GSOC).

Inhaltsverzeichnis

Frontmatter

Chapter 1. Overview Space Segment

Abstract

Chapter 1 summarizes the space segment, introducing the “Space Environment”, “Space System Engineering” and “Space Communications”, the latter establishing the connection to the ground segment.

The space environment in which spacecraft have to operate is an alien world in which we would not survive for more than a few minutes without protection. Fortunately, in this respect, spacecraft are generally more robust than humans and it is possible for spacecraft to regularly operate continuously for more than 15 years. In the case of Voyager 1, launched over 35 years ago, the spacecraft continues to operate and to communicate with the Earth 18 billion km away. It is interesting to question how this longevity can be achieved when there is no possibility of maintenance and the environment, at first sight, appears so unattractive.

System engineering requires skills that are traditionally associated with both art and science. Good system engineering not only requires the art of technical leadership including creativity, problem solving, knowledge and communication skills but it also requires the science of systems management or the application of a systematic disciplined approach. In this section the systematic disciplined approach is considered in more detail.

Radio communication with a spacecraft has to deal with the fact that there are large distances between transmitter and receiver, possible low elevation angles resulting in a substantial attenuation by the atmosphere and large Doppler shifts due to the orbital velocity of the satellite. Moreover, the ionosphere reflects or absorbs certain frequencies that are thus unusable for space communications.

Adrian R. L. Tatnall, Felix Huber

Chapter 2. Mission Operations

Abstract

The success of a space mission depends not only on a properly designed and built space segment and the successful launch via a launch segment. It also depends on the ground segment and successful mission operations, carried out by a team of experts using the infrastructure and processes of the mission’s ground segment. Its organization and design as well as the assembly, integration, test, and verification (AITV) are therefore equally important as the respective activities of the space and launch segment. A ground segment thereby comprises a ground system, i.e., infrastructure, hardware, software, and processes, and a team that conducts the necessary operations on the space segment.

In space operations two phases are distinguished that are of equal importance: mission preparation and mission execution.

This chapter describes the tasks and activities that are necessary for the preparation and execution of a mission, i.e., what must be done by whom and in which order to enable mission operations of a particular space mission. It gives the questions that arise automatically when analyzing the requirements of a mission and how these questions are answered with a design based on available resources and respecting project-specific constraints.

This is followed by examples of lessons learnt, in particularly in the course of multiple LEOP phases of communication satellites. It will then handle the process of dealing with system contingencies, mostly on spacecraft side and wrap up with several spacecraft anomalies and the attempts to deal with them.

Andreas Ohndorf, Sabrina Eberle, Thomas Uhlig, Ralf Faller, Michael Schmidhuber, Ralph Ballweg

Chapter 3. Communication and Infrastructure

Abstract

This chapter describes the design aspects of a typical Mission Control Center (MCC) and the Ground Station Network. The Mission Control Center—as the name implies—is the central ground facility of a space mission. It is the central point where all data and management information concerning the spacecraft are consolidated. These data are received, checked, and processed, decisions are made and—in case of an emergency—the respective procedures are performed in order to restore the nominal conditions of the mission. The way how the MCC operates is defined by its design which specifies its capabilities, flexibility, and robustness.

Within this chapter we focus on several aspects of the design of a control center. At first the necessary infrastructure is analyzed. Then the design of the local control center network is examined followed by the software needed.

The Ground Station Network (GSN) plays a major role in space missions. It has to establish communication with the spacecraft and with other control centers, support specific spacecraft characteristics, and provide operability and safety of the mission. Due to its nature, the GSN takes part in cross-support activities between different organizations and agencies. The GSN covers several functional aspects—the communication path between control center and the ground stations (transporting online data, off-line data, voice), the management of the stations and their antennas, as well as coordination tasks and station scheduling.

Marcin Gnat, Michael Schmidhuber

Chapter 4. Flight Dynamic Operations

Abstract

This chapter describes the flight dynamics system of a satellite platform divided into attitude and orbit control.

The section about the orbital aspects has two parts. The first one addresses theoretical aspects and gives an overview over the methods used to describe a satellite orbit, the orbit perturbations, orbit maneuvers, and orbit maintenance. These topics are important for the understanding and successful performing of flight dynamics operations, which are presented in the second part.

The section about spacecraft attitude starts with an introduction to Methods used for description of the spacecraft attitude including the use of so-called quaternions. After a brief section about “disturbances” affecting the attitude, the determination, propagation, and control of a spacecraft attitude are described. Finally, the tasks of an Attitude and Orbit Control Systems are described including some examples.

Michael Kirschner, Jacobus Herman, Ralph Kahle

Chapter 5. Mission Planning

Abstract

This chapter deals with Mission Planning as one of the key elements of a spaceflight mission. All activities on board need to be brought into a temporal content to ensure optimal mission success and facilitate the synchronized interaction of multiple components, systems, or teams. The first step is to develop a common language, which allows the mathematical modeling of the basic problem itself. The first section of the chapter therefore introduces the basic elements of mission planning and explains the mutual interactions between them. In the second section this concept is applied to unmanned satellite missions, whereas the third section presents the mission planning within the International Space Station project as one example for human spaceflight planning.

Christoph Lenzen, Tobias Göttfert, Falk Mrowka, Thomas Uhlig, Dennis Herrmann, Jérôme Campan

Chapter 6. Spacecraft Subsystem Operations

Abstract

Chapter 6 describes the operation tasks of the various subsystems of a classic unmanned satellite in Earth orbits.

The first section deals with the Telemetry, Commanding, and Ranging Subsystem which allows the radio frequency transmission of remote monitoring and control information of a spacecraft. The next section describes the operations of the On-Board Data-Handling Subsystem, i.e., the spacecraft components that handle the on-board distribution and processing of data. The third section is about operations of the Power and Thermal Subsystem including energy sources, management, and storage for as well as heat sources, transfer, and dissipation. This is followed by a section on operating the propulsion subsystem including principles, configuration, real time, and offline operations. The last section, finally, depicts the operations of the Attitude and Orbit Control System.

Michael Schmidhuber, Sebastian Löw, Kay Müller, Sina Scholz, Franck Chatel, Ralf Faller, Jürgen Letschnik

Chapter 7. Special Topics

Abstract

Although most of the concepts presented in this book can be applied to any spaceflight mission, there are some endeavors which have very special requirements and challenges. Chapter 7 deals with these specific cases. The first section presents the additional requirements and conceptual adaptations which are required to put a human being on board of a spacecraft. The second section deals with robotic missions. Operating mechanically moveable elements in space leads to very specific problems and challenges, which are described in more detail. Leaving the gravitational field of the earth requires also some special considerations, which are covered in section three. Finally we deal in the fourth section with lander operations, which require another vast field of demanding skills and knowledge.

Jérôme Campan, Thomas Uhlig, Dennis Herrmann, Florian Sellmaier, Paolo Ferri, Stephan Ulamec

Backmatter

Titel: Spacecraft Operations
herausgegeben von: Thomas Uhlig
Florian Sellmaier
Michael Schmidhuber
Verlag: Springer Vienna
Electronic ISBN: 978-3-7091-1803-0
Print ISBN: 978-3-7091-1802-3
DOI: https://doi.org/10.1007/978-3-7091-1803-0

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Inhaltsverzeichnis

Frontmatter

Chapter 1. Overview Space Segment

Chapter 2. Mission Operations

Chapter 3. Communication and Infrastructure

Chapter 4. Flight Dynamic Operations

Chapter 5. Mission Planning

Chapter 6. Spacecraft Subsystem Operations

Chapter 7. Special Topics

Backmatter

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