It’s no secret that getting to the moon is expensive, and the fuel cost is one of the primary reasons. That’s why reducing it has been one of the primary objectives. Now it seems that scientists have found a way to reduce fuel costs by using a more economical route.
A new study published in the journal Astrodynamics has mapped out a new route from Earth’s orbit to the Moon’s, one that could meaningfully reduce mission costs. The trick is a cosmic pit stop at a gravitational balance point sitting between the two bodies, called the L1 Lagrange point.
The new route saves at least 58.80 m/s of fuel compared to the most efficient paths previously described. That number might not sound dramatic, but as lead researcher Allan Kardec de Almeida Júnior puts it, “every meter per second equates to a massive amount of fuel consumption” in space travel.
How did they find this route?
The team used a mathematical framework called the Theory of Functional Connections, which dramatically reduces the computing power needed to simulate spacecraft trajectories.
That efficiency allowed them to run 30 million different route simulations, compared to the 280,000 in a previous benchmark study. More simulations meant a better chance of finding a more fuel-efficient route, and that’s exactly what happened.
The most cost-effective route turned out to use the branch of the gravitational corridor that passes near the Moon first, which is counterintuitive since the spacecraft is traveling from Earth, not toward it.
The reason it works is that passing close to the Moon allows the spacecraft to take advantage of a gravity assist, reducing the fuel needed to enter the intermediate orbit.
What’s the advantage of L1 Lagrange point pit stop?
Once a spacecraft enters the L1 Lagrange point, it can hold its position indefinitely using a control system, waiting until the mission is ready to proceed to lunar orbit. Unlike a direct trajectory, this intermediate orbit keeps the spacecraft in continuous communication with both Earth and the Moon, which is a massive advantage.
The researchers also said that adding the Sun’s gravitational influence to their simulations could unlock even greater fuel savings, though that would require planning for a specific launch date.
With hundreds of space missions expected in near future, a more fuel-efficient route means more payload, lower costs, and ultimately more missions that can greatly increase our rate of success.
