I’ve learned about the Lagrangian points when I was studying for my Masters thesis and came across Astropolitik, a book that talks about powers in space. I mean I kinda knew what Lagrangian points were, The James Webb telescope is going to one of them but more detail was required in order to understand space security.
First thing I did, a quick Google search that turned in a few results, including the awesome explanation of Neil DeGrasse-Tyson who happens to be my absolute favourite staryteller out there.
He said something like this:
The Lagrangian spots are places in the rotating Earth-Moon system where the
gravity of Earth, the gravity of the Moon and the centrifugal forces of the rotating system
balance. This makes an object located at the Lagrangian points require little or no energy to maintain its orbit and makes those points strategically important in space exploration. There are five Lagrangian points in the orbit of Earth/Sun/etc. “Interplanetary trajectories that begin at Lagrangian points require very little fuel to reach other Lagrangian points or even other planets. Unlike a launch from a planet’s surface, where most of your fuel goes to lift you off the ground, launching from a Lagrangian point would resemble the a ship leaving dry-dock— becoming adrift into the ocean with only a minimal investment of fuel.” (deGrasse Tyson 2002) The ship would be pulled by the gravitational force of the Earth, Moon or the outer solar system. All planets have Lagrangian points and they can be considered gateways to the rest of solar system. “From the Sun-Earth Lagrangian points you are half way to Mars; not in
distance or time but in the all-important category of fuel consumption.” (ibid)
Back to space security, Astropolitik argues that even though space is often compared with discovering new worlds on Earth, in space, there are no mountains or hills, and fuel is calculated by the Lagrangian points. Although space is often considered just another geography, the author of the book considers it also a mix of “hyper-frontier, and an inhuman environment.” (Astropolitik, 2002). One thing is clear, we need science to conquer space.
My favourite analogy came from other articles that argued that the Lagrangian points are exactly the places where the refuelling “gas stations” of the future should be just because they are the cheapest to run (maintain in orbit).
A more detailed article, written by Erik Vermaat from Christchurch, and reproduced here with his permission is available in the link below. Erik, now a retired science teacher, taught physics and he is leading the Royal Astronomical Society of New Zealand Education Section.
Lagrangian points text – by Erik Vermaat
Featured image:
Diagram of the Lagrange Points associated with the Sun-Earth system. WMAP orbits around L2, which is about 1.5 million km from the Earth. Lagrange Points are positions in space where the gravitational forces of a two body system like the Sun and the Earth produce enhanced regions of attraction and repulsion. These can be used by spacecraft to reduce fuel consumption needed to remain in position.
Note: Image is not to scale
Credit: NASA / WMAP Science Team
