Pulsars GPS: Navigating Smoothly Through Space

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A group of scientists from Down Under are claiming they've solved the problem of navigating through space without getting lost. Their solution: radio and x-ray emissions from pulsars could be used to position a spacecraft.

Astronomers have known about pulsars for a few decades, and they have since discovered that the small spinning stars emitting their 'pulses' have some use, like determining the behavior and location of the pulsar itself through use of a telescope. However, the new study demonstrates the practice working in reverse, too; that a pulsar's pulse can be used to precisely locate the position of a telescope used to view it.

Dr. George Hobbs, a co-author and an astronomer with the Commonwealth Scientific and Industrial Research Organisation in Australia, has said that, vicariously, "If the telescopes were on board a spacecraft, then we could get the position of the spacecraft."

The way spacial guiding systems work currently, ships are tracked and guided from the ground. The spacecraft in question would have to be within open view of at least four pulsars every seven days for at least an hour, Hobbs says, in order for the system to work properly. "Whether you can do them all at the same time or have to do them one after the other depends on where they are and exactly what kind of detector you use," he added.

The original paper was authored by Chinese PhD student Deng Xinping at the National Space Science Center in Beijing, and will be published in the journal Advances in Space Research. Pulsar navigation had been proposed as early as 1974, and NASA is now exploring the technique.

Spacecraft that intended to travel outside the realm of our known solar system would need an autonomous tracking device to navigate safely, and since gyroscopes and accelerometers are only useful up to a point, a new method is needed. "Navigating with pulsars avoids these problems," Deng said of the new method. The latest iterations of the navigation software are able to pin down a spacecraft's position in the solar system within 20km and the craft's velocity within 10 cm per second. Dr. Hobbs said of the results: "to our knowledge, this is the best accuracy anyone has ever been able to demonstrate."

The official press release is found here.

[Image via a Youtube video on Pulsars]