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These "manoeuvres" were an essential part of the earliest visits to the outer solar system.
In the book, an Earth spaceship by Martian brigands who are determined to get their hands on the Moon's one key resource, radiactum. Radiactum was "the catalyst mineral which was revolutionising industry."
The mathematics of the manner in which the orbits of comets were altered by close approaches to planets was known in the late eighteenth century. However, this idea was not applied to space craft until much later.
In the early nineteen-twenties, Walter Hohmann demonstrated that the lowest energy path between any two planets is an ellipse that is tangential to the orbits of both the planets. However, no rockets existed until the 1960's that were powerful enough to generate the initial thrust, and a minimum energy orbit would take thirty years from Earth to Neptune - and forty years to Pluto.
Also in the 1920's, Hermann Oberth described a powered flyby, or Oberth maneuver, that is a maneuver in which a spacecraft falls into a gravitational well and then uses its engines to further accelerate as it is falling, thereby achieving additional speed. The resulting maneuver is a more efficient way to gain kinetic energy than applying the same impulse outside of a gravitational well.
The Oberth effect is distinct from a gravity-assist “slingshot” maneuver, which describes an elastic momentum and energy exchange between an unpowered spacecraft and a planet when both are under the gravitational influence of a third body, typically the Sun
In the volume published in 1932, Nikolai Alexyevich Rynin introduced the reader to the mysterious Yuri Vasilievich Kondratyuk. In a volume of Interplanetary Flight published in Russian in 1932, this description of gravity assisted flight was included:
A historical review of the theory of gravity‑assists
in the pre‑spacefight era
It's not clear whether or not this published work was related to earlier, unpublished work by the author dating back as far as 1920.
To the best of my knowledge, the concept of "gravity assist" as a means of altering the speed or course of a spacecraft was apparently not discovered by the scientific world (in English, anyway) until some 20 years after the publication of Cummings' novel. In a footnote A C Clarke indicates the first ref he's aware of was the paper "Perturbation Manoeuvres" by Derek Lawden (Journal of the British Interplanetary Society, vol 13, no 5, Sept 1954). Lawden is a mathematician, and in the early fifties worked on the optimization of rocket trajectories. It is also reported that a summer intern at JPL in 1961, Michael A. Minovitch, showed that the gravity field of a planet could provide thrust to a spacecraft. He demonstrated that careful design of the trajectory to a target planet could provide a gravity assist to move from that planet to a second planet.
Historians of science still differ on this issue.
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Science Fiction
Timeline
Brin's 1990 Novel Earth Still Full Of Predictions
'... making the point that their likenesses, every move they made, were being transmitted.'
Gaia - Why Stop With Just The Earth?
'But the stars are only atoms in larger space, and in that larger space the star-atoms could combine to form living matter, thinking matter, couldn't they?'
Microsoft VASA-1 Creates Personal Video From A Photo
'...to build up a video picture would require, say, ten million decisions every second. Mike, you're so fast I can't even think about it. But you aren't that fast.'
Splendid View Of Eclipse From Orbit Visualized And Repurposed By Arthur C. Clarke
'The area affected was five hundred kilometres across, and perfectly circular.'
Goldene - A Two-Dimensional Sheet Of Gold One Atom Thick
'Hasan always pitched a Gauzy - a one-molecule-layer tent, opaque, feather-light, and very tough.'
SpaceX Wants A Moonbase Alpha
'And he had been sent with troops, supplies and bombs to command Russia's most trusted post, the Moonbase.'
Vast Apartment Living Will Get Even More Vast
'What is your population', I asked. 'About eighty millions.'
NASA Wants Self-Driving Or Remote-Controlled Vehicles For Lunar Astronauts
'THE autobus turned silently down the wide street of Hydropole. Robot-guided, insulated from noise and cold...'
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