China’s First Satellite Guided by X-ray Pulses
China has launched the first satellite in the world which will not be guided from Earth but instead will be guided by the powerful x-ray pulses of distant stars.In order to support the big strategies for deep space exploration, comprising of a manned Lunar mission together with Martian lander, China has launched its first x-ray navigation system in the world.
The X-ray Pulsar Navigations 1 - XPNAV1 satellite, launched on November 10 aboard a solid-fuelled Long March 11 rocket from the Jiuquan Space Launch Centre in the Gobi Desert, is said to be the first x-ray navigation system in the world that will go in orbit, that will defeat NASA;s Station Explorer for X-ray Timing and Navigation Technology –SEXTANT, scheduled to be installed on the ISS somewhere next year.
The navigation system is said to be dependent on x-ray pulsars set up in systems with two stars. Basically a dense neutron star’s strong magnetic field tends to pull in gas from the other star and when the gas influences the neutron star, it generates a strong X-ray hotspot.
Millisecond Pulsars Generate X-ray Pulses at Short Intervals
If the spin axis and the magnetic axis of the neutron star are not aligned, while the neutron star tends to rotate, pulses will be generated as the X-ray hotspots move in and out of the view of the observer. This is a beneficial tool for navigation.
Millisecond pulsars have a tendency to generate x-ray pulses at short intervals which by measuring the time differential from multiple known pulsars, such as GPS utilising pulsars rather than satellites, a spacecraft has the tendency of determining its location in the solar system within 5 km, which is good for deep space. The purpose is to find pulsars which tend to offer pulses at a reliable pace. X-ray pulsars frequently speed up or slow down the regularity of their bursts.
If it goes as intended, the XPNAV1 would accumulate data to build the pulsar x-ray database and would then be capable of using the data to verify its location independently. The 529-pound satellite is said to have two detectors for measuring x-rays generated by pulsars. XPNAV1, over the next five to ten years would build a database of x-rays from 26 pulsars which would measure their frequencies against other electromagnetic action in space.
X-ray Navigation – Superior Precision/Reliability
Moreover it would also measure the accuracy as well as its consistency of pulsar x-rays against the background noise in space without the need to worry about atmospheric interference. It would verify the usability of the data by checking the data to see if the same can predict the location of the satellite without depending on other navigation aids.
The benefit of x-ray navigation comprise of superior precision and reliability and the spacecraft would not need to depend on radio signals which tend to take longer in travelling into deep space and miss signal fidelity. X-ray navigation tends to be much cheaper and the spacecraft would not need large expensive ground based radio antennae for navigations signals.
Besides this the spacecraft would also be more autonomous wherein it would save bandwidth for the transmission of scientific data back to earth. The achievement of XPNAV1 would mean that China has not only been successful in achieving a most important milestone in space technology but has also enabled Chinese talkonauts as well as robotic probes to travel more easily further than orbit.
