Galactic Positioning System | Out Of This World Weekly

We are all familiar with using the Global Positioning System (GPS) to get us to our location safely, whether we are in a plane, boat, train, or car.  This system also provides information for agriculture, environmental, public safety, recreation, and mapping applications.  GPS satellites in orbit make this possible by sending specific signals that allow a receiver to triangulate our position.  Ironically, even though the satellites are in space, GPS does not work in space outside of Earth’s orbit and never was intended to as the satellites point their signal at the Earth.  A similar system is used where radio signals are sent from different points on Earth out into space so that we can direct robotic spacecraft to their destination safely.  The bad part about this system is that the farther from Earth the spacecraft is, the less precision that can be achieved.  The farthest spacecraft that we have, the Voyager probes, are only known at an approximate location within several square miles.  If we are ever to venture out further than our solar system then we are going to need a better system because our current system simply will not work around other stars. 

If we are going to pinpoint our position within our galaxy, we are going to need points of reference within our own galaxy.  Researchers at Max-Planck Institute for Extraterrestrial Physics in Garching, Germany have found these reference points with pulsar stars.  Pulsar stars are a form of deceased star that emits a detectable x-ray signal that repeats with an exact frequency that is related to the rotation speed of the pulsar.  By comparing several signals from different pulsars and comparing them to what would be expected at a reference point, a fairly precise location and velocity can be found.  It isn’t quite clear if 3 to 6 pulsars would give an accurate enough position but it may very well be possible to keep track of dozens of pulsars, with each additional pulsar being tracked adding to the precision of the data. 

This technique would for determining position and velocity work anywhere in our galaxy but it could also be used to augment current positioning systems both in our solar system and on Earth.  Because the navigation system is based on pulsars and not based upon signals from Earth, robotic probes could continue navigational tracking even when objects such as planets or moons are directly in between the spacecraft and Earth.  This would also mean that expensive transmitting stations would not have to be maintained and funded.  On Earth, we could benefit from these pulsar signals with not only increased precision in our GPS receivers but also a backup if something should happen to the GPS satellites.  This may seem far fetched to have a multitude of GPS satellites simultaneously fail but this scenario has been explored as a type of first strike against a country.  After all, if you take away a military capability like GPS with anti-satellite missiles then you could easily affect that militaries ability to maneuver accurately.  Several countries have demonstrated their ability to shoot down satellites and because of this, several countries operate independently operated and controlled GPS systems such as the U.S., E.U., Russia, China, and India. 

This is not an entirely new idea, as science fiction novels have talked about this possibility for decades but this is the first time that it has been shown it could be done with existing scientific equipment.  While the need for us to have accurate positioning capabilities around distant stars does not yet exist, we will eventually need to master this technology for this purpose.  The fact that we can use this system to augment Earth GPS without having to send up and maintain expensive satellites is a bonus that cannot be ignored.  The strategic benefits of such a system in a world where a great many people and soldiers depend on knowing their exact position cannot be ignored.  This is yet another example of a technology which is necessary for deep space exploration that could have profound effects on our daily lives without the average person having to change anything or even notice that they are being handed more accurate and dependable information. 

No comments :

Post a Comment