NASA and ESA are racing to bring GPS to the moon

Their missions are expected to launch in the next two years.

NASA is involved in two upcoming missions designed to help bring satellite navigation (satnav) to the moon — and if they’re successful, future astronauts will be able to pinpoint their locations on the lunar surface as easily as we can find ours here on Earth.

Satnav 101: Satnav systems are networks of satellites in Earth’s orbit that beam radio signals toward the planet’s surface. 

Receivers in our phones, cars, and other tech can analyze information contained in those signals to calculate their distance from a satellite. If a receiver can pick up signals from multiple satellites, it can use the distance information to triangulate its location on Earth.

“The [GPS] signal [that reaches the moon] is 1,000 times weaker than on Earth.”

Cyril Botteron

The challenge: Space agencies would love to be able to use satnav on the moon and in cislunar space (between the Earth and moon). However, while some of the networks’ radio signals do pass by the edge of Earth, they’re incredibly faint and hard to detect by the time they reach the moon.

“The [GPS] signal [that reaches the moon] is 1,000 times weaker than on Earth,” Cyril Botteron, CEO of Switzerland’s Space PNT, told Space.com. “On top of that, the signal only comes from one side, whereas on Earth, you are surrounded by those satellites on all sides.”

That forces them to rely on more expensive, cumbersome methods to determine the locations of objects on the moon’s surface and in cislunar space — but that could soon change thanks to a pair of upcoming missions.

satnav moon
A diagram showing the path of signals from a global navigation satellite system. Credit: NASA / Danny Baird

The LuGRE: In 2024, NASA plans to launch the Lunar GNSS Receiver Experiment (LuGRE), a joint mission with the Italian Space Agency that will send a receiver capable of picking up weak signals from two major satnav networks — the US’s GPS and the EU’s Galileo — to the lunar surface.

Once in place, LuGRE will unfurl its antenna and — hopefully — become the first spacecraft on the lunar surface to receive signals from navigation satellites. NASA will then use data collected during the 12-day mission to develop satnav systems for future use on and around the moon.

Lunar Pathfinder: NASA is also working with ESA on Lunar Pathfinder, a moon orbiter set to launch in 2025 with “NaviMoon,” a satnav receiver being developed by Space PNT, on board.

satnav moon
The NaviMoon receiver and amplifier. Credit: ESA

Once the orbiter is in place, NaviMoon will use signals from GPS and Galileo satellites — as well as measurements of several forces, including the gravitational pulls of the Earth, sun, and moon — to determine its own location with an accuracy of less than 100 meters.

“[A]t such a distance the faint Galileo and GPS signals it makes use of will be barely distinguishable from background noise,” said Javier Ventura-Traveset, head of ESA’s Navigation Science Office. “This demonstration will imply a true change of paradigm for lunar orbiting navigation.”

Proving that a NaviMoon receiver can locate itself is just the first step. The next is to have several NaviMoon-equipped satellites act like their own GPS or Galileo network for the moon — beaming signals to astronauts, rovers, and other spacecraft on its surface.

We’d love to hear from you! If you have a comment about this article or if you have a tip for a future Freethink story, please email us at [email protected].

Related
Could hydrogen-fuelled flights be a reality by 2035?
By 2035, hydrogen fuel cells could be used to electrify mid-range flights and hydrogen combustion aircraft could be used on long-haul flights.
Startup’s bladeless flying car is designed to reach Mach 0.8
Jetoptera is designing quieter, safer vertical take-off and landing (VTOL) vehicles with bladeless propulsion systems.
NASA announces alien-hunting Habitable Worlds Observatory
NASA has announced that it is developing the Habitable Worlds Observatory, a new space telescope optimized to hunt for extraterrestrial life.
World’s largest plane sets new flight record
A new test flight puts the world’s largest plane one step closer to helping the US develop — and respond to — hypersonic weapons.
SpaceX puts Starlink promises to astronomers in writing
SpaceX has signed an agreement with the National Science Foundation detailing its plans to minimize Starlink’s impact on astronomy.
Up Next
Subscribe to Freethink for more great stories