Latest By
Category:


Armor
Artificial Intelligence
Biology
Clothing
Communication
Computers
Culture
Data Storage
Displays
Engineering
Entertainment
Food
Input Devices
Lifestyle
Living Space
Manufacturing
Material
Media
Medical
Miscellaneous
Robotics
Security
Space Tech
Spacecraft
Surveillance
Transportation
Travel
Vehicle
Virtual Person
Warfare
Weapon
Work

"In WWII, they had a saying that there are no atheists in foxholes. I think the modern equivalent of that is that there are no jaded, bored people in the high-tech industry, in the land of really good hardcore geeks."
- Neal Stephenson

Gravity Assist  
  Using the gravity and orbital speed of a celestial body to change speed and course of a spacecraft.  

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."

We were at this time no more than some sixty-five thousand miles from the moon's surface. The Planetara presently would swing upon her direct course for Mars. There was nothing that would cause passenger comment in this close passing of the moon; normally we used the satellite's attraction to give us additional starting speed.
From Brigands of the Moon, by Ray Cummings.
Published by Astounding Stories of Super Science in 1930
Additional resources -

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.

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 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.

Thanks to an alert reader for this item!

Comment/Join this discussion ( 2 ) | RSS/XML | Blog This |

Additional resources:
  More Ideas and Technology from Brigands of the Moon
  More Ideas and Technology by Ray Cummings
  Tech news articles related to Brigands of the Moon
  Tech news articles related to works by Ray Cummings

Gravity Assist-related news articles:
  - Gravity Assist Will Help Pluto-Bound Craft
  - The Amazing Gravity-Assisted Journey Of Rosetta

Articles related to Space Tech
Is 'The Pulsar Positioning System' Evidence For SETI?
Are Observed Radio Bursts An Alien Propulsion Technology?
Caltech's ET Laboratory Looks For New Earths
Shh! USAF's Secret X-37B Space Plane Breaks Record

Want to Contribute an Item? It's easy:
Get the name of the item, a quote, the book's name and the author's name, and Add it here.

<Previous
Next>

Google
  Web TechNovelgy.com   

 

 

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

More News

Cattle Avoidance Feature In Indian Autonomous Cars
'The driver went about the business of gently slipping the teflon-coated metal scoop beneath the first animal...'

Project KOVR Fashion Protection From Infosphere
'... the entire shroudlike membrane took on whatever physical characteristics were projected at any nanosecond.'

Twist Bioscience High Density Digital Data On DNA
'They tied the memory to the bloodline and that was their record!'

'We're Not Creating A Terminator' Say Russians About Gun-Wielding Robot Fedor
Nobody is thinking about the Terminator. Westworld, maybe.

Vantablack Now IMMEASURABLY Black
'a black coating now thatís ninety-nine percent absorptive...'

Mercedes-Benz Autonomous Taxi Fleet In 3 Years
'... the taxi utilized sophisticated electronic sensors to perceive its surroundings.'

Is 'The Pulsar Positioning System' Evidence For SETI?
'For a hyperspace jump, you need at least four beacons for an accurate fix.'

Someday, You Might Like VR Enough To Move In
'That barrier was going to melt away someday soon. The transhumanists had promised...'

Humans Use Mental Power For Turtle Slavery
Now we need to start looking for animals with fingers...

Solar-Powered Moisture Vaporator
'The atmosphere yielded its moisture with reluctance.'

More SF in the News

More Beyond Technovelgy

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.