The new era of space travel and scientific discovery kicked off by the and return of Artemis I will be astounding, but before the big discoveries can be made astronauts will have to deal with a very Earthbound problem: Figuring out just where the heck they are.

Right now, there is no easy way to navigate the 230,000-mile schlep to the Moon, nor is there anything helping you find your way once you get there. It’s not like you can take a right at the Hardee’s and have a calming female voice tell you your destination is only a few hundred thousand miles ahead. It takes numbers, and a guy who is good at numbers either in the cockpit or on the ground. This is a problem when the spacecraft can spend many long minutes out of communication with ground control. It’s a cumbersome and expensive system, but luckily, the international space community is on the job.

The answer might lie in the technology we already have in the sky. Engineers were able to use Earth-focused satellites to communicate with sensors 116,300 miles away. From :

Surprisingly, the cheapest way to bring satnav to deep space is to harness the satellites around the Earth, Elizabeth Rooney, a senior , told Insider. The company is working with ESA to develop satellite navigation in space.

There are a few big problems with this approach. Chief among them is that these satellites point toward the Earth.

That means that most of the satellites’ signal is blocked and only a little spills over. The bit that spills over is a lot weaker than the main signal, and it gets even weaker further away from Earth.

Given all these constraints, it could seem like using this signal to navigate to the moon would be impossible. But engineers have spent decades developing sensitive detectors that could harness that signal from deep space.

And they succeeded.

In 2019, four satellites were able to determine their position in space using signals from the Earth’s GPS satellites.

Both the European Space Agency and NASA are planning to test even more sensitive sensors on future moon missions to try and hone in on satellite signals. If they can truly connect with sats back home, we could get closer to achieving autonomous moon travel. But eventually that won’t be enough. To help direct humans on the lunar surface, we’re going to need a fleet of satellites specifically around the moon. NASA calls its project LunaNet, and it’s part of the , which is the culmination of America’s plan to return to the moon. It needs to be designed to play well with ESA technology and, eventually, will be the source of high-speed internet on the moon.

Artemis I launched , rounded the and touched down Earth-side in December. Artemis II, which will carry astronauts around the moon in a similar trajectory, is slated to launch in late 2024, . Artemis III, which will be humanity’s first boots on the moon since 1972, could launch as early as 2025.

You can read more about using satellites in space on .