Neutron Star Interior Composition Explorer

{{Short description|NASA telescope on International Space Station}}

{{Use American English|date=December 2021}}

{{Use dmy dates|date=December 2021}}

{{Infobox spaceflight

| name = NICER

| image = NICER on the ISS.jpg

| image_caption = NICER telescope mounted on the Integrated Truss Structure of the International Space Station

| image_size = 300px

| mission_type = Neutron star astrophysics

| operator = NASA{{\}}GSFC{{\}}MIT

| website = https://heasarc.gsfc.nasa.gov/docs/nicer/

| mission_duration = 18 months (planned)
{{time interval|3 June 2017|show=ymd}} (in progress)

| manufacturer =

| launch_mass = {{cvt|372|kg}} {{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/spacex_crs-11_mission_overview.pdf|title=SpaceX CRS-11 Mission Overview |publisher=NASA|access-date=3 June 2017}} {{PD-notice}}

| dimensions =

| power =

| launch_date = 3 June 2017, 21:07:38 UTC{{cite news|url=https://spaceflightnow.com/2017/06/03/reused-dragon-cargo-capsule-launched-on-journey-to-space-station/|title=Reused Dragon cargo capsule launched on journey to space station|publisher=Spaceflight Now|first=Stephen|last=Clark|date=3 June 2017|access-date=3 June 2017}}

| launch_rocket = Falcon 9 Full Thrust, B1035.1

| launch_site = Kennedy Space Center, LC-39A

| launch_contractor = SpaceX

| entered_service =

| disposal_type =

| deactivated =

| last_contact =

| orbit_reference = Geocentric orbit

| orbit_regime = Low Earth orbit

| orbit_periapsis = {{cvt|402|km}}

| orbit_apoapsis = {{cvt|407|km}}

| orbit_inclination = 51.64°

| orbit_period = 92.66 minutes

| apsis = gee

| instruments = X-ray Timing Instrument (XTI)

| insignia = NICER - SEXTANT logo.png

| insignia_caption = NICER * SEXTANT mission patch

| insignia_size = 200px

| programme = Explorer program

| previous_mission = ASTRO-H (NeXT)

| next_mission = SES-14 (GOLD)

}}

The Neutron Star Interior Composition ExploreR (NICER) is a NASA telescope on the International Space Station, designed and dedicated to the study of the extraordinary gravitational, electromagnetic, and nuclear physics environments embodied by neutron stars, exploring the exotic states of matter where density and pressure are higher than in atomic nuclei. As part of NASA's Explorer program, NICER enabled rotation-resolved spectroscopy of the thermal and non-thermal emissions of neutron stars in the soft X-ray (0.2–12 keV) band with unprecedented sensitivity, probing interior structure, the origins of dynamic phenomena, and the mechanisms that underlie the most powerful cosmic particle accelerators known.{{cite book |chapter-url=https://heasarc.gsfc.nasa.gov/docs/nicer/papers/NICER-SPIE-July2012-v4.pdf|title=Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray|series=Proceedings of the SPIE |first1=Keith C.|last1=Gendreau|first2=Zaven|last2=Arzoumanian|first3=Takashi|last3=Okajima |chapter=The Neutron star Interior Composition ExploreR (NICER): An Explorer mission of opportunity for soft x-ray timing spectroscopy |s2cid=119892783|editor3-first=Jan-Willem A.|editor3-last=Den Herder|editor2-first=Stephen S.|editor2-last=Murray|editor1-first=Tadayuki|editor1-last=Takahashi|volume=8443|page=844313|date=September 2012 |doi=10.1117/12.926396|bibcode=2012SPIE.8443E..13G}} NICER achieved these goals by deploying, following the launch, and activation of X-ray timing and spectroscopy instruments. NICER was selected by NASA to proceed to formulation phase in April 2013.{{cite press release |url=https://www.nasa.gov/home/hqnews/2013/apr/HQ_13-088_Astro_Explorer_Mission_.html|title=NASA Selects Explorer Investigations for Formulation|publisher=NASA|first=J. D.|last=Harrington|date=5 April 2013 |access-date=23 April 2013}}

NICER-SEXTANT uses the same instrument to test X-ray timing for positioning and navigation,{{cite web|url=https://www.nasa.gov/press-release/goddard/2017/nasa-neutron-star-mission-begins-science-operations |title=NASA Neutron Star Mission Begins Science Operations|publisher=NASA|last=Garner|first=Rob|date=17 July 2017|access-date=26 January 2018}} and MXS is a test of X-ray timing communication. In January 2018, X-ray navigation was demonstrated using NICER on ISS.{{cite web|url=https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/iss-utilization-nicer-sexta-1|title=ISS Utilization: NICER/SEXTANT|work=eoPortal|publisher=European Space Agency|access-date=26 January 2018|archive-date=8 February 2021|archive-url=https://web.archive.org/web/20210208211909/https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/iss-utilization-nicer-sexta-1|url-status=dead}}

In May 2023, NICER's thermal shields developed a leak that allowed stray light to enter the telescope. A repair kit containing specialized patches was delivered to the station by the Cygnus NG-21 resupply mission in August 2024,{{cite web |last=Kazmierczak |first=Jeanette |url=https://science.nasa.gov/missions/station/iss-research/nicer/repair-kit-for-nasas-nicer-mission-heading-to-space-station/ |title=Repair Kit for NASA's NICER Mission Heading to Space Station |work=NASA |date=30 July 2024 |access-date=30 July 2024}} and were applied by the stranded astronauts in a January 16, 2025 spacewalk.{{cite web |url= https://astrobites.org/2025/02/02/a-nicer-solution-for-an-aging-x-ray-telescope/ |title=A NICER solution for an aging X-ray telescope |date=2 Feb 2025}}

Launch

By May 2015, NICER was on track for a 2016 launch, having passed its critical design review (CDR) and resolved an issue with the power being supplied by the ISS.{{cite news|url=https://www.nasa.gov/feature/goddard/nasa-s-multi-purpose-nicer-sextant-mission-on-track-for-2016-launch|title=NASA's Multi-Purpose NICER/SEXTANT Mission on Track for 2016 Launch|publisher=NASA |first=Lori|last=Keesey|date=12 May 2015|access-date=27 October 2015}} Following the loss of SpaceX CRS-7 in June 2015, which delayed future missions by several months, NICER was finally launched on 3 June 2017, with the SpaceX CRS-11 ISS resupply mission aboard a Falcon 9 v1.2 launch vehicle.{{cite web |url=https://heasarc.gsfc.nasa.gov/docs/nicer/news/nicer_whatsnew.html|title=NICER Manifested on SpaceX-11 ISS Resupply Flight|series=NICER News|publisher=NASA|date=1 December 2015|access-date=14 June 2017 |quote=Previously scheduled for a December 2016 launch on SpaceX CRS-12, NICER will now fly to the International Space Station with two other payloads on SpaceX Commercial Resupply Services (CRS)-11, in the Dragon vehicle's unpressurized Trunk.}} {{PD-notice}}

Science instrument

NICER's primary science instrument, called the X-ray Timing Instrument (XTI), is an array of 56 X-ray photon detectors. These detectors record the energies of the collected photons as well as with their time of arrival. A Global Positioning System (GPS) receiver enables accurate timing and positioning measurements. X-ray photons can be time-tagged with a precision of less than 300 ns.{{cite web|url=https://heasarc.gsfc.nasa.gov/docs/nicer/papers/NICER-SPIE-July2012-v4.pdf|quote=Each photon detected by NICER is time-tagged with an absolute precision of much better than 300 nanoseconds |title=The Neutron star Interior Composition ExploreR (NICER): an Explorer mission of opportunity for soft x-ray timing spectroscopy|year=2012|author=Gendreau|display-authors=et al.}} {{PD-notice}} In August 2022 a fast X-ray follow-up observation program was started with the MAXI instrument named "OHMAN (On-orbit Hookup of MAXI and NICER)" to detect sudden bursts in X-ray phenomena.{{Cite web |title=OHMAN (On-orbit Hookup of MAXI And NICER) has started! – immediate X-ray follow-up program combining JAXA and NASA instruments on ISS |url=https://www.isas.jaxa.jp/en/topics/003208.html |access-date=2023-01-13 |website=ISAS |language=en}}

During each ISS orbit, NICER will observe two to four targets. Gimbaling and a star tracker allow NICER to track specific targets while collecting science data. In order to achieve its science objectives, NICER will take over 15 million seconds of exposures over an 18-month period.{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/nicer-factsheet-final.pdf|title=NICER: Neutron star Interior Composition Explorer|series=NASAFacts|publisher=NASA|access-date=14 June 2017}} {{PD-notice}}

X-ray navigation and communication experiments

An enhancement to the NICER mission, the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT), will act as a technology demonstrator for X-ray pulsar-based navigation (XNAV) techniques that may one day be used for deep-space navigation.{{cite conference|url=https://ntrs.nasa.gov/citations/20150001327|title=SEXTANT – Station Explorer for X-ray Timing and Navigation Technology |conference=AIAA Guidance, Navigation, and Control Conference. 5–9 January 2015 Kissimmee, Florida|first1=Jason W.|last1=Mitchell|first2=Munther A.|last2=Hassouneh|first3=Luke M. B.|last3=Winternitz |first4=Jennifer E.|last4=Valdez|first5=Samuel R.|last5=Price|first6=Sean R.|last6=Semper|first7=Wayne H.|last7=Yu|first8=Zaven|last8=Arzoumanian|first9=Paul S.|last9=Ray|first10=Kent S.|last10=Wood |first11=Ronald J.|last11=Litchford|first12=Keith C.|last12=Gendreau|display-authors=5|date=January 2015|id=GSFC-E-DAA-TN19095; 20150001327}}

= XCOM =

{{Update section|date=February 2020}}

As part of NICER testing, a rapid-modulation X-ray device was developed called Modulated X-ray Source (MXS), which is being used to create an X-ray communication system (XCOM) demonstration. If approved and installed on the ISS, XCOM will transmit data encoded into X-ray bursts to the NICER platform, which may lead to the development of technologies that allow for gigabit bandwidth communication throughout the Solar System.{{cite web|url=https://www.nasa.gov/feature/goddard/2016/nasa-s-navcube-could-support-an-x-ray-communications-demonstration-in-space-a-nasa-first|title=NASA's NavCube Could Support an X-ray Communications Demonstration in Space — A NASA First|publisher=NASA|first=Lori|last=Keesey|date=4 November 2016|access-date=5 November 2016}} {{PD-notice}} {{as of|February 2019}} the XCOM test is scheduled for spring 2019.[https://phys.org/news/2019-02-nasa-x-ray-space.html NASA set to demonstrate X-ray communications in space February 2019] XCOM (inc MXS) was delivered to the ISS in May 2019.[https://spaceflightnow.com/2019/05/10/x-ray-communications-experiment-delivered-to-space-station/ X-ray communications experiment delivered to space station May 2019] Once the test was complete XCOM and the STP-H6 payload malfunctioned in September 2021. It was removed in November 2021 and disposed of on Cygnus NG-16.{{Cite web |title=STP-H6 |url=https://space.skyrocket.de/doc_sdat/stp-h6.htm |access-date=2022-07-30 |website=Gunter's Space Page |language=en}}

Selected results

In May 2018, NICER discovered an X-ray pulsar in the fastest stellar orbit yet discovered.{{cite web|url=https://www.nasa.gov/feature/goddard/2018/nasa-s-nicer-mission-finds-an-x-ray-pulsar-in-a-record-fast-orbit|title=X-ray Pulsar Found in Record-fast Orbit|publisher=NASA|last=Garner|first=Rob|date=10 May 2018|access-date=12 May 2018}} {{PD-notice}} The pulsar and its companion star were found to orbit each other every 38 minutes.

On 21 August 2019 (UTC; 20 August in the U.S.), NICER spotted the brightest X-ray burst so far observed.[https://www.space.com/nicer-telescope-brightest-x-ray-burst.html NICER Telescope Spots Brightest X-Ray Burst Ever Observed] It came from the neutron star SAX J1808.4−3658 about 11,000 light-years from Earth in the constellation Sagittarius.

Astronomers using NICER found evidence that a neutron star from a low-mass X-ray binary in NGC 6624 is spinning at 716 Hz (times per second), or 42,960 revolutions per minute, the same velocity as the fastest known spinning neutron star PSR J1748−2446ad and the only one in such a binary system.{{Cite journal |last1=Jaisawal |first1=Gaurava K. |last2=Bostancı |first2=Z. Funda |last3=Boztepe |first3=Tuğba |last4=Güver |first4=Tolga |last5=Strohmayer |first5=Tod E. |last6=Ballantyne |first6=David R. |last7=Beck |first7=Jens H. |last8=Göğüş |first8=Ersin |last9=Altamirano |first9=Diego |last10=Arzoumanian |first10=Zaven |last11=Chakrabarty |first11=Deepto |last12=Gendreau |first12=Keith C. |last13=Guillot |first13=Sebastien |last14=Ludlam |first14=Renee M. |last15=Ng |first15=Mason |date=2024-11-01 |title=A Comprehensive Study of Thermonuclear X-Ray Bursts from 4U 1820–30 with NICER: Accretion Disk Interactions and a Candidate Burst Oscillation |journal=The Astrophysical Journal |volume=975 |issue=1 |pages=67 |bibcode=2024ApJ...975...67J |doi=10.3847/1538-4357/ad794e |issn=0004-637X |doi-access=free|arxiv=2504.07328 }}{{Cite web |last=Starr |first=Michelle |date=2024-11-06 |title=Wild Star Discovered Spinning an Incredible 716 Times Per Second |url=https://www.sciencealert.com/wild-star-discovered-spinning-an-incredible-716-times-per-second |access-date=2024-11-10 |website=ScienceAlert |language=en-US}}

Gallery

KSC-20170603-PH AWG06 0008 (35119281635, cropped).jpg|Launch of CRS-11 with NICER aboard

Nicer-extraction-loop 0.gif|NICER extracted from Dragon's trunk at ISS

Neutron star Interior Composition Explorer (NICER) - 34718447596.jpg|Array of X-ray lenses

File:NICER graphic still (plain).png|Full instrument view

NICER graphic labeled.png|Labeled diagram of NICER

See also

{{Portal|Spaceflight|Astronomy|Physics}}

References

{{Reflist}}