
Astronautics (or cosmonautics) is the theory and practice of travel beyond
Earth's atmosphere
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...
into
outer space
Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, pred ...
.
Spaceflight is one of its main applications and
space science its overarching field.
The term ''astronautics'' (originally ''astronautique'' in
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with Franc ...
) was coined in the 1920s by
J.-H. Rosny
J.-H. Rosny was the pseudonym of the brothers Joseph Henri Honoré Boex (1856–1940) and Séraphin Justin François Boex (1859–1948), both born in Brussels. Together they wrote a series of novels and short stories about natural, prehistoric and ...
, president of the
Goncourt academy
The Goncourt brothers (, , ) were Edmond de Goncourt (1822–1896) and Jules de Goncourt (1830–1870), both France, French Naturalism (literature), naturalism writers who, as collaborative sibling authors, were inseparable in life.
Background
...
, in analogy with
aeronautics
Aeronautics is the science or art involved with the study, design, and manufacturing of air flight–capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identif ...
. Because there is a degree of technical overlap between the two fields, the term
aerospace
Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astrona ...
is often used to describe both at once. In 1930,
Robert Esnault-Pelterie published the first book on the new research field.
The term ''cosmonautics'' (originally ''cosmonautique'' in French) was introduced in 1930s by
Ary Sternfeld with his book ''Initiation à la Cosmonautique'' (Introduction to cosmonautics) (the book brought him the
Prix REP-Hirsch, later known as the Prix d'Astronautique, of the
French Astronomical Society in 1934.
l'Astronomie, 1934, p. 325–326.
/ref>)
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 and the magnetic belts of low Earth orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...
. Space launch vehicles
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and syste ...
must withstand titanic forces, while satellites
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotop ...
can experience huge variations in temperature in very brief periods.[''Understanding Space: An Introduction to Astronautics'', Sellers. 2nd Ed. McGraw-Hill (2000)] 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
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such a ...
.
History
The early history of astronautics is theoretical: the fundamental mathematics of space travel was established by Isaac Newton
Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a " natural philosopher"), widely recognised as one of the g ...
in his 1687 treatise '' Philosophiæ Naturalis Principia Mathematica''.[''Fundamentals of Astrodynamics'', Bate, Mueller, and White. Dover: New York (1971).] Other mathematicians, such as Swiss Leonhard Euler
Leonhard Euler ( , ; 15 April 170718 September 1783) was a Swiss mathematician, physicist, astronomer, geographer, logician and engineer who founded the studies of graph theory and topology and made pioneering and influential discoveries in ma ...
and Franco-Italian Joseph Louis 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 spaceflight puzzled the literary imaginations of such figures as Jules Verne
Jules Gabriel Verne (;''Longman Pronunciation Dictionary''. ; 8 February 1828 – 24 March 1905) was a French novelist, poet, and playwright. His collaboration with the publisher Pierre-Jules Hetzel led to the creation of the ''Voyages extraord ...
and H. G. Wells. At the beginning of the 20th century, Russian cosmist Konstantin Tsiolkovsky derived the rocket equation, the governing equation for a rocket-based propulsion, enabling computation of the final velocity of a rocket from the mass of spacecraft (), combined mass of propellant and spacecraft () and exhaust velocity of the propellant ().
:
By the early 1920s, Robert H. Goddard was developing liquid-propellant rocket
A liquid-propellant rocket or liquid rocket utilizes a rocket engine that uses liquid propellants. Liquids are desirable because they have a reasonably high density and high specific impulse (''I''sp). This allows the volume of the propellant ta ...
s, 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
Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, with three stages, and powered with liquid fuel. It was flown from 1 ...
.
The Prix d'Astronautique (Astronautics Prize) awarded by the Société astronomique de France, the French astronomical society, was the first prize on this subject. The international award, established by aviation and astronautical pioneer Robert Esnault-Pelterie and André-Louis Hirsch, was given from 1929 to 1939 in recognition of the study of interplanetary travel and astronautics.
By the mid-1950s, the Space Race between the USSR and the US had begun.
Subdisciplines
Although many regard astronautics itself as a rather specialized subject, engineers and scientists working in this area must be knowledgeable in many distinct fields.
* Astrodynamics – the study of orbital motion. Those specializing in this field examine topics such as spacecraft trajectories, ballistics and celestial mechanics.
* Spacecraft propulsion – how spacecraft change orbits, and how they are launched. Most spacecraft have some variety of rocket engine
A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive Jet (fluid), jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, i ...
, and thus most research efforts focus on some variety of rocket propulsion, such as chemical, nuclear or electric.
* Spacecraft design – a specialized form of systems engineering that centers on combining all the necessary subsystems for a particular launch vehicle or satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioiso ...
.
* Controls – keeping a satellite or rocket in its desired orbit (as in spacecraft navigation) and orientation (as in attitude control).
* Space environment
Space environment is a branch of astronautics, aerospace engineering and space physics that seeks to understand and address conditions existing in space that affect the design and operation of spacecraft. A related subject, space weather, deals ...
– although more a sub-discipline of physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...
rather than astronautics, the effects of space weather and other environmental issues constitute an increasingly important field of study for spacecraft designers.
* Bioastronautics
Bioastronautics is a specialty area of biological and astronautical research which encompasses numerous aspects of biological, behavioral, and medical concern governing humans and other living organisms in a space flight environment; and includ ...
Related fields of study
* Aeronautics
Aeronautics is the science or art involved with the study, design, and manufacturing of air flight–capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identif ...
and aerospace
Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astrona ...
* Mechanical engineering
* Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...
See also
* Atmospheric reentry
* Frank Malina
* French space program
* Hermann Oberth
* Sergei Korolev
* Wernher von Braun
References
Further reading
*
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