NASA is set to launch the world's first mission tomorrow to study rapidly spinning neutron stars – the densest objects in the universe – nearly 50 years after they were discovered.<br/><br/>The same platform will also carry out the world's first demonstration of X-ray navigation in space. The agency plans to launch the two-in-one Neutron Star Interior Composition Explorer (NICER) aboard SpaceX CRS-11, a cargo resupply mission to the International Space Station (ISS) to be launched aboard a Falcon 9 rocket tomorrow.<br/><br/>The launch was earlier planned for June 1, but was delayed due to poor weather. About a week after its installation, this one-of-a-kind investigation will begin observing neutron stars, the densest objects in the universe.<br/><br/>The mission will focus especially on pulsars – those neutron stars that appear to wink on and off because their spin sweeps beams of radiation past us, like a cosmic lighthouse. During its 18-month mission, NICER will collect X-rays generated from the stars' tremendously strong magnetic fields and from hotspots located at their two magnetic poles.