Written by Kevin C. Nice | issued
Most people have never heard of Lagrangian points, but they have become the new battleground in the new space race between China and the United States, as world powers compete in space exploration.
What is a Lagrangian point?
A Lagrangian point is a point in interplanetary space where the centripetal force required for a smaller object to orbit stably between two bodies is balanced by the gravitational force between the two bodies. These points are named after Joseph Louis Lagrange, an Italian astronomer, physicist, and mathematician who made significant contributions to the fields of classical mechanics, celestial mechanics, number theory and analysis.
There are five Lagrangian points in our solar system, each given a designation L1 through L5. L4 and L5 are located 60 degrees in front and behind the Earth in solar orbit, making them ideal locations for “parking” telescopes and satellites. A spacecraft that enters these zones can remain there for long periods of time without expending large amounts of fuel to maintain its position.
This makes these Lagrangian points perfect places to observe weather patterns on Earth. L1 and L2 offer distinct advantages for communications, surveillance, and space research due to their proximity to the Moon and the general absence of atmospheric interference.
Lagrangian points are important for communications and observation, fueling technological and economic competition between the US and China
L2 is 1.5 million kilometers (932,000 miles) away from the Sun, orbiting at about the same speed as Earth, but about four times farther from us than the Moon.
L2 is one of the most important Lagrangian points for observation purposes. Located just on the opposite side of the Moon from Earth, it offers spectacular views of deep space and is an ideal location for sensitive space telescopes such as the James Webb Space Telescope. The Queqiao relay satellite was sent to L2 by China’s Chang’e 4 lunar probe, and was the first satellite of its kind to land on the far side of the moon from Earth.
Meanwhile, the US is also planning missions targeting the Lagrangian point L2, such as the Gateway lunar outpost planned for later this decade.
As China continues to ramp up its space program, the United States is particularly interested in contesting positions to prevent the Chinese Communist Party from gaining dominance in communications and surveillance.
Lagrangian points are important for communications and observation, fueling technological and economic competition between the United States and China, and are a major focus of NASA and the Department of Defense. A bipartisan House committee recently produced a report proposing about 150 policy recommendations for a “fundamental reset” of U.S.-China relations.
The report was released after a year-long investigation into the conflict between the two countries. It focused particular attention on Lagrangian points, with recommendations suggesting that NASA and the Department of Defense receive funding for programs to counter the Chinese Communist Party’s (CCP) “malign ambitions” in space. .
As China continues to ramp up its space program, the United States is particularly interested in contesting positions to prevent the Chinese Communist Party from gaining dominance in communications and surveillance.
For this reason, the Lagrangian point has become a central focus of the new space race between the United States and China.