NASA’s NICER to study neutron stars

NASA today launched the world's first mission to study rapidly spinning neutron stars - the densest objects in the universe - nearly 50 years after their discovery. During the same mission NASA will also carry out the world's first demonstration of X-ray navigation in space.

The agency launched the two-in-one Neutron Star Interior Composition Explorer (NICER) aboard SpaceX CRS-11, a cargo resupply mission to the International Space Station (ISS) aboard a Falcon 9 rocket today.

The launch was earlier set for 1 June, but was delayed due to poor weather. The investigation would get underway a week after installation, when NICER will begin observing neutron stars, the densest objects in the universe.

The focus of the mission - are pulsars, neutron stars that appear to wink on and off because their spin sweeps beams of radiation past us, like a cosmic lighthouse.

The extreme nature of neutron stars and pulsars had led to a great deal of interest since their existence was proposed in 1939. The stars were discovered in 1967.

Neutron stars are the remnants of massive stars that, had exhausted their nuclear fuel, and exploded and collapsed into super-dense spheres.

The most visible part of NICER, a one-meter-wide cube, is made of solid aluminum with 56 holes drilled through its face. The instrument is equipped with an array of special lenses that deflect x-rays and focus them towards sensors fixed on the inner wall behind them.

According to deputy principal investigator for the NICER Mission, astrophysicist Zaven Arzoumanian, not much was known about neutron stars, the densest objects in the universe.

''They are only about 16 to 20 kilometers across but can contain the mass of up to two of our suns compressed into that tiny volume so we think they are made mostly of neutrons.''