It's ONLY Rocket Science: An Introduction in Plain English

357 Pages·2008·7.538 MB·English

by  Dr. Lucy Rogers (auth.)

Astronomers’ Universe
Other titles in this series
Rejuvenating the Sun and Avoiding Other Global Catastrophes
Martin Beech
Origins: How the Planets, Stars, Galaxies, and the Universe
Began
Steve Eales
Calibrating the Cosmos: How Cosmology Explains Our Big
Bang Universe
Frank Levin
The Future of the Universe
A.J. Meadows
Dr. Lucy Rogers
It’s ONLY Rocket Science
An Introduction in Plain English
Dr. Lucy Rogers CEng MIMechE FRAS
Isle of Wight, UK.
www.itsonlyrocketscience.com
ISBN 978-0-387-75377-5 e-ISBN 978-0-387-75378-2
DOI: 10. 1007/978-0-387-75378-2
Library of Congress Control Number: 2007939660
© 2008 Springer Science+Business Media, LLC
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For Laura and Hannah
Acknowledgements
There are many people and organizations that have helped, either
directly or indirectly, to make this book a reality. I would first like
to thank the British Association for the Advancement of Science
and the Guardian Newspaper, for encouraging me, as an engineer,
to become involved with the media. I was fortunate enough to be
awarded one of the BA’s Media Fellowships at the Guardian news-
paper, and this scheme opened my eyes to the possibility of sharing
science with everyone, and not just limiting it to academia and
industry. Without this scheme and the wise words of Tim Radford,
the then science editor at the Guardian, I would never have started
writing.
I would also like to thank John Thomson and West Didsbury
Astronomical Society for rekindling my interest in astronomy, and
to Starchaser Industries for the opportunity to actually play, I mean
work, with rockets through all stages of development.
My thanks also go to the team at Springer, particularly John
Watson, who first believed in the project, and also to Harry Blom,
my editor, and his assistant editor Chris Coughlin.
I have been constantly amazed at the generosity of the many
people who have taken the time to answer my questions and
explain facets of rocket science that, at the start of the project, I did
not even know were involved. These include the staff at NASA, in
particular Kylie Clem, Allard Beutel and Jennifer Ross-Nazzal and
also to Colin R. McInnes, A.D. King, Russell Eberst, Claude Phipps,
Gregory Benford and also the members of the HearSat email list.
Neil Chance read the first draft of each chapter and, with que-
ries and probing questions, made me think much more deeply than
I had originally intended. The book is much clearer because of this,
and I thank him for it. I would also like to thank Jan Foy and John
Langley for their encouragement and time.
I must also thank my brother, Benjamin Rogers, who, since
our school days, has explained many aspects of science and maths
clearly and patiently. He has provided invaluable support when my
vii
viii Acknowledgements
understanding of the physics involved in rocket science wavered.
However, any mistakes in the book are mine.
Finally my love and thanks go to my parents and to my
partner Stephen J. Griffiths, who have supported and encouraged
me throughout the whole process of preparing this book.
Contents
1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Space. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Solar Wind and the Van Allen Radiation Belts. . . . . . . . . . 2
Gravity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Orbits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Inclination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Eccentricity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Space Debris. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Magnitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Space Law. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2 Rockets and Spacecraft . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Pre-spacefl ight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Rocket Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Multistaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Launch Pad to Orbit. . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Launch Vehicles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Sounding Rockets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Attitude Control and Movement . . . . . . . . . . . . . . . . . . . . 34
Gravity Gradients and Tidal Forces. . . . . . . . . . . . . . . . 34
Spin Stabilization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Three Axis Stabilization. . . . . . . . . . . . . . . . . . . . . . . . . 37
Magnetic Torquers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Spacecraft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Communication and Navigation Spacecraft. . . . . . . . . 40
Fly-by Spacecraft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Orbiter Spacecraft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Atmospheric Spacecraft. . . . . . . . . . . . . . . . . . . . . . . . . 41
Lander and Rover Spacecraft . . . . . . . . . . . . . . . . . . . . . 42
Observatory Spacecraft. . . . . . . . . . . . . . . . . . . . . . . . . . 42
ix
x Contents
Penetrator Spacecraft and Impactors. . . . . . . . . . . . . . . 43
Manned Spacefl ight . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Power Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Primary Energy Source. . . . . . . . . . . . . . . . . . . . . . . . . . 44
Secondary Power Source . . . . . . . . . . . . . . . . . . . . . . . . 48
Power Control and Distribution System. . . . . . . . . . . . 50
Thermal Control Systems. . . . . . . . . . . . . . . . . . . . . . . . . . 50
Thermal Protection for Re-entry Vehicles . . . . . . . . . . 51
3 Space Missions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Launch System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Launch Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Launch Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Landing Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Earth Landing Sites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Landing on Other Bodies in the Solar System. . . . . . . . 67
Emergency Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Launch Escape System. . . . . . . . . . . . . . . . . . . . . . . . . . 74
Shuttle Emergency Egress System. . . . . . . . . . . . . . . . . 75
Shuttle Launch Abort. . . . . . . . . . . . . . . . . . . . . . . . . . . 75
In-fl ight Crew Escape System . . . . . . . . . . . . . . . . . . . . 77
Mission Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Testing and Pre-launch. . . . . . . . . . . . . . . . . . . . . . . . . . 78
Launch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
End of Life. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Reliability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4 Movement in Three Dimensions. . . . . . . . . . . . . . . . . . . . 83
Orbits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Orbit Shape. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Types of Orbit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Lagrangian Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Lagrangian Point 1 (L1). . . . . . . . . . . . . . . . . . . . . . . . . . 93
Lagrangian Point 2 (L2). . . . . . . . . . . . . . . . . . . . . . . . . . 94
Lagrangian Point 3 (L3). . . . . . . . . . . . . . . . . . . . . . . . . . 95
Lagrangian Points 4 and 5 (L4 and L5). . . . . . . . . . . . . . 95
Getting into Orbit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Changing Orbits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Perturbations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Station-keeping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Contents xi
Changing the Altitude or Shape of an Orbit. . . . . . . . . 98
Low Thrust Trajectory. . . . . . . . . . . . . . . . . . . . . . . . . . 101
Orbit Inclination Changes or Out-of-Plane
Orbit Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Rendezvous and Intercept . . . . . . . . . . . . . . . . . . . . . . . 103
Interplanetary and Interstellar Trajectories . . . . . . . . . 104
Gravity Assist, Fly-by or Sling Shot . . . . . . . . . . . . . . . 105
Ground Tracks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5 Propulsion Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Chemical Rocket Propulsion . . . . . . . . . . . . . . . . . . . . . . . 116
Solid Propellants or Rocket Motors. . . . . . . . . . . . . . . . 116
Liquid Propellants or Rocket Engines. . . . . . . . . . . . . . 120
Gelled Propellants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Hybrid Propellants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Cold Gas Propellants . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Electric Propulsion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Electrothermal Systems. . . . . . . . . . . . . . . . . . . . . . . . . 128
Electrostatic Engines or Ion Drives. . . . . . . . . . . . . . . . 128
Electromagnetic or Magnetoplasma Engines . . . . . . . . 130
Nuclear Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Nuclear Electric Rocket. . . . . . . . . . . . . . . . . . . . . . . . . 131
Solar Thermal Propulsion (STP) . . . . . . . . . . . . . . . . . . . . . 131
Other Forms of Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . 132
6 Navigation in Three Dimensions. . . . . . . . . . . . . . . . . . . . 133
Coordinate Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Locating Spacecraft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Inertial Navigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Magnetometers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
External References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Earth-based Navigation and Tracking Systems . . . . . . 148
Lunar and Interplanetary Systems. . . . . . . . . . . . . . . . . 148
Time Dilation and Relativistic Effects. . . . . . . . . . . . . . . . 149
7 Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Tracking, Telemetry and Command. . . . . . . . . . . . . . . . . . 151
Radiowave Communication . . . . . . . . . . . . . . . . . . . . . 152