NICER
NICER — an X-ray telescope mounted on the International Space Station (since 2017) that studies the densest matter in the universe inside neutron stars, and pioneered X-ray navigation.
Key facts
Mission & specifications
Mission
- Operator
- NASA
- Launched
- June 3, 2017
- Status
- Active
Trajectory
- Distance from the Sun
- 1.01 AU
- Distance from Earth
- 387,570 km
- Distance from Venus
- 0.646 AU
Mission
NICER — the Neutron star Interior Composition Explorer — is a small X-ray telescope with an outsized scientific reach, bolted to the outside of the International Space Station since 2017. Its target is the neutron star: the collapsed core left when a massive star explodes, where more than the Sun's mass is crushed into a sphere the size of a city, creating the densest matter in the universe short of a black hole. By precisely timing the X-rays from rapidly spinning neutron stars, NICER measures their size and mass, and from that infers what happens to matter at densities no laboratory on Earth can reproduce. Its careful measurements of neutron-star radii have become some of the best constraints on the physics of ultra-dense matter. NICER also ran a remarkable side experiment called SEXTANT, which used the steady, clock-like pulses of neutron stars as natural beacons to let a spacecraft work out its own position — a demonstration of X-ray navigation that could one day guide probes through deep space without any signal from Earth.
- 2017Launch to the ISSLaunch
Delivered by a Dragon cargo ship and mounted on the outside of the station.
- 2018X-ray navigation demonstratedMilestone
The SEXTANT experiment uses pulsars as beacons to fix a spacecraft's own position.
- 2019Measuring a neutron starMilestone
Maps a pulsar's surface and pins down its size, constraining ultra-dense matter.
Images
Images from open archives · credit shown per image