'Astronautics', or Astronautical Engineering, is the branch of
engineering that deals with machines designed to exit or work entirely beyond the
Earth's atmosphere. In other words, it is the science and technology of
space flight.
Overview
The term ''Astronautics''
[1] was coined by analogy with
Aeronautics. As there is a certain degree of technology overlap between the two fields, the term
Aerospace is often used to describe them both.
As with aeronautics, the restrictions of mass, temperatures, and external forces require that applications in space survive extreme conditions: high-grade
vacuum, the
radiation bombardment of
interplanetary space, the
magnetic belts of
low Earth orbit.
Space launch vehicles must withstand titanic forces, while
satellites can experience huge variations in temperature in very brief periods.
[2] Extreme constraints on mass cause astronautical engineers to face the constant need to save mass in the design in order to maximize the actual
payload that reaches
orbit.
History
The early history of astronautics is theoretical: the fundamental mathematics of space travel was established by
Isaac Newton in the
17th century in his treatise
Principia.
[3] Other mathematicians, such as
Euler and
Lagrange also made essential contributions in the
18th and
19th centuries. In spite of this, Astronautics did not become a practical discipline until the mid-
20th century. On the other hand, the question of space flight tickled the literary imaginations of such figures as
Jules Verne and
HG Wells.
At the beginning of the
20th century,
Konstantin Tsiolkovsky derived the famous
rocket equation, the governing
equation for a
rocket-based propulsion. This equation makes it possible to compute the final velocity of a rocket from the mass of spacecraft(
), combined mass of propellant and spacecraft (
) and exhaust velocity of the propellant (
).
For more information on the mathematical basis of space travel, see
space mathematics.
By the early
1920s, the
American Robert Goddard was developing liquid-fueled
rockets, which would in a few brief decades become a critical component in the designs of such famous rockets as the
V-2 and
Saturn V.
Sub-Disciplines
Although many regard Astronautics itself as a rather specialized subject, engineers and scientists working in this area must be knowledgeable about many distinct fields of knowledge.
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Astrodynamics: the study of orbital motion. Those specializing in this field examine topics such as
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Propulsion: how spacecraft change orbits, and how they are
launched. Most spacecraft have some variety of
rocket engine, and thus most
research efforts focus on some variety of
rocket propulsion, such as
chemical,
nuclear propulsion, or
electric propulsion.
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Spacecraft design: a specialized form of
systems engineering which centers on combining all the necessary sub-systems for a particular
launch vehicle or
satellite
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Controls: keeping a satellite or rocket in its desired orbit (as in
spacecraft navigation) and orientation (as in
attitude control).
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Space environment: although more a sub-discipline of
Physics rather than Astronautics, the effects of
space weather and other environmental issues constitute an increasingly important field of study for spacecraft designers.
Related Fields of Study
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Aeronautics and
Aerospace
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Mechanical Engineering
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Physics
References
1. ''From Astronautics to Cosmonautics'', Gruntman. BookSurge, North Charleston, S.C. (2007)
2. ''Understanding Space: An Introduction to Astronautics'', Sellers. 2nd Ed. McGraw-Hill (2000)
3. ''Fundamentals of Astrodynamics'', Bate, Mueller, and White. Dover: New York (1971).
See also
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Aerospace
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Atmospheric reentry
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Konstantin Tsiolkovsky
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Space Race
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Robert Goddard
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Wernher von Braun
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Spacefaring