China to launch pioneering pulsar navigation satellite in November 

China is already well on the way to establishing its own version of America's GPS network with its Beidou satellite constellation, but now it is seeking to take navigation and timing to stellar levels. 

In November China will launch the X-ray pulsar navigation satellite - XPNAV-1 - a satellite that will conduct the world's first test of the possibilities of using the regular emission of X-ray signals from pulsars for spacecraft navigation.

The spacecraft will attempt to triangulate its position relative to the Sun using the highly regular emissions from pulsars.

If successful, this could dramatically cut the reliance of craft in deep space on the huge ground-based communications networks currently in use, such as the Deep Space Network (DSN) and the European Space Tracking (ESTRACK) network, and avoid the related time-delay issues.

The China Academy of Space Technology (CAST), a major research and development institute for China's state-led space program, announced the news on October 8 to celebrate the 60th anniversary of Chinese aerospace development.

Above: A rendering of China's XPNAV-1 satellite (CAST).

Discovered in 1967, pulsars are former large stars that have collapsed down into incredibly dense rotating spheres a matter of kilometres in diameter.

If the electromagnetic radiation emitted from two opposite points of these spinning 'neutron stars' sweep past Earth, they appear to pulse, giving them their name, and the reason they are sometimes referred to as celestial 'lighthouses'.

The highly-energetic and regular pulses of photons allow a device sensitive enough for miniaturisation for use on spacecraft.

Shuai Ping, chief scientist behind the research of XPNAV-1 satellite, told People's Daily that the key aim of the satellite is to detect the details of X-ray signals of 26 relatively close pulsars, and to create a "pulsar navigation database."

If launch is successful, XPNAV-1 will undercut a NASA mission by a number of months to be the first such test. 

In early 2017, NASA plans to launch the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) as part of its Neutron star Interior Composition Explorer (NICER) mision to the International Space Station to demonstrate pulsar-based navigation of spacecraft.

Quelle: gbtimes