Pulsars act like GPS for tracking space probes
Slight deviations of pulsars - small spinning stars delivering regular `blips` of radio waves - from the expected arrival times can give information to very precisely determine the position of our telescopes.
Washington: Slight deviations of pulsars - small spinning stars delivering regular `blips` of radio waves - from the expected arrival times can give information to very precisely determine the position of our telescopes.
Dr George Hobbs (CSIRO) said that if the telescopes were on board a spacecraft, then we could get the position of the spacecraft.
Observations of at least four pulsars, every seven days, would be required.
Hobbs said that each pulsar will have to be observed for about an hour and whether it can be done 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 is used.
Spacecraft within the solar system are usually tracked and guided from the ground: this is the role of CSIRO`s Canberra Deep Space Communication Complex, for instance. But the further out the craft go, the less accurately their locations can be measured.
For voyages beyond the solar system, spacecraft would need an on-board (`autonomous`) system for navigation. Gyroscopes and accelerometers are useful tools, but the position information they give becomes less accurate over time.
Deng Xinping, PhD student at the National Space Science Center in Beijing, who is first author on the paper describing the system, said that navigating with pulsars avoids these problems.
Hobbs and his colleagues have made a very detailed simulation of a spacecraft navigating autonomously to Mars using this combination of technologies and their TEMPO2 software.
Hobbs said that the spacecraft can determine its position to within about 20 km and its velocity to within 10 cm per second.
The new version of the software lets the astronomers rule out unseen masses, including any supposedly undiscovered planets, such as the notorious Nibiru.
A paper describing the working of the system has been accepted for publication by the journal Advances in Space Research.