Navigating your way through the vast cosmos can be quite challenging with the millions of celestial objects in the way, and a lack of galactic roads to help guide you along.
This 'Galactic,' rather than 'Global Positioning System' will use the guiding light of pulsars, a type of star that acts as a cosmic lighthouse.
Pulsars are a fast-rotating neutron star, or the super dense remains of a star that exploded in a supernova. These stars emit electromagnetic radiation in the form of bright, narrow beams that sweep across the cosmos in a round motion as the star itself spins.
If you are observing the stars from a distance, it will look as though they are pulsating in flashes of light, which is how they got their name.
A team of engineers is developing a way to use these pulsars as guiding lighthouses through an X-ray telescope that's about the size of a washing machine and is placed on the outside of the International Space Station.
The Neutron star Interior Composition Explorer, also known as NICER, collects and timestamps the light coming from neutron stars across the sky.
The telescope has a software called the Station Explorer for X-ray Timing and Navigation Technology, or SEXTANT, which creates a GPS-like system using the beacons of light emanating from the neutron stars.
"Pulsations from some neutron stars are very stable, some even as stable as terrestrial atomic clocks in the long term, which makes them potentially useful in a similar way,” Luke Winternitz, a researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement.
Because these pulsations are stable, they become predictable therefore scientists are able to determine when the beacons of light would arrive at a certain area in the Solar System.
By timing their arrival to a detector on a spacecraft, and comparing that to when they are meant to arrive at a reference point in the Solar System, the team of engineers are able to then provide information on navigating through the cosmos based on the predictions of the stars' beams of light.
“It could work anywhere in the solar system and even carry robotic or crewed systems beyond the solar system," Jason Mitchell, director of the Advanced Communications and Navigation Technology Division in NASA’s Space Communication and Navigation Program, said in a statement.
The team are hoping to use this new navigation method to guide the upcoming Artemis mission to the Moon, currently slotted for the year 2024. The astronauts making their journey back to Earth could potentially use the GPS system to supplement the onboard navigation capabilities.
“Gateway’s orbit around the Moon of approximately six-and-a-half days would let us stare at pulsars for much longer times,” Mitchell said. “That’s where the trade comes in; the instrument is like a bucket and you’re filling that bucket with enough X-ray photons to generate a measurement of when that pulse arrived. You could have a detector a fraction the size of NICER.”