NASA Is Creating the First-Ever Cosmic GPS for Spaceships and Lost Astronauts
This past week saw the release of the new Netflix sci-fi series Lost in Space, but soon real-life astronauts won't have to worry about getting lost at all—instead, they'll be using a new kind of cosmic GPS to navigate their way back home, as well as pull off precision flight paths that will allow them to enter the orbits of alien moons.
The technology is based on the Neutron Star Interior Composition Explorer, a telescope mounted on the International Space Station.
NICER watches the cloud of X-rays that permeates the universe and picks out the periodic flashes created by pulsars, which expel X-rays so regularly that they beat out atomic clocks when it comes to accuracy.
The comparison to atomic clocks is appropriate, considering that they're an essential component of traditional GPS—here's a quick description of how traditional GPS works:
"To determine its location, the GPS receiver uses the time at which each signal from a satellite was emitted, as determined by the onboard atomic clock and encoded into the signal, together the with speed of light, to calculate the distance between itself and the satellites it communicated with. The orbit of each satellite is known accurately. Given enough satellites, it is a simple problem in Euclidean geometry to compute the receiver's precise location, both in space and time."
With an onboard version of the NICER telescope, a spacecraft could do the same thing with pulsars, which are relatively easy to spot in the vast emptiness of space: the new device would use three pulsars to calculate its position, then use a fourth to make sure it's correctly calibrated.
This has a big advantage over trying to keep a spacecraft in constant radio contact with Earth, since a break in communication would potentially doom a crew's ability to navigate themselves back home.
On top of that, the use of pulsars to find one's exact position means that spacecraft can navigate themselves with incredible accuracy, making it possible to adjust their course with precision and pull off missions that are nearly impossible now, such as sending a probe into orbit around a distant moon.
It's an exciting development, especially with space colonization on the horizon—with NICER-based telescopes, we'll always be able to find our way back home.