NICER Mission Timeline


Current Activity

NICER Observing Timeline. Please see Upcoming and recent past pointings for up-to-date NICER observation scheduling. For the final as-flown timeline, you can use the HEASARC Timeline Tool, which is populated within two weeks of observation.

Targets of Opportunity and Directory's Discretionary Time. Details of previously submitted TOO/DDT requests are available at the TOO Summary page. Please review the NICER ToO Policy. Any questions regarding how to make TOO requests should be sent to the NICER Helpdesk via the HEASARC's Feedback Form.

MAXI OHMAN Targets. Summary of OHMAN Targets observed by NICER: OHMAN (Orbiting High-energy Monitor Alert Network) X-ray follow-up observation program uses JAXA's MAXI all-sky monitor to detect sudden X-ray bursts and to automatically notify NICER for immediate followup. See the OHMAN Summary page for a list of OHMAN triggers.

NICER Enhanced Visibility Calculator

The NICER Enhanced Visibility Calculator calculates visibilities for targets over roughly the next 2-week period taking into account ISS orientation and target occultation by ISS structures and other relevant constraints. These visibility intervals are more accurate than visibilities based solely on Sun and Moon avoidance.

Other NICER Activities

Early Post-Launch NICER activities

  • July 13 Begin Science Program
  • June 21-July 12 Initial calibration and hardware commissioning
  • June 17 NICER uses Raster scan of Serpens X-1 to determine X-ray instrument and star tracker alignment
  • June 14 NICER is powered up, NICER is deployed, NICER range of motion is verified by robotic camera
  • June 12-13 NICER is installed on the ISS ELC2
  • June 11 2017 NICER is extracted from the Dragon trunk

Latest News

  • NICER Patching Assessment after Spacewalk 91 (24 Jan 2025)
    Verification observations of the installation of 9 patches during U.S. Spacewalk 91 show that the detectors behind the patched optics are receiving lower levels of optical light during orbit night, and the level of light inside the instrument during orbit day is substantially reduced. Some continued data degradation due to sunlight during orbit day is, however, still evident. NICER continues to operate with its full measurement capabilities during orbit night, and assessment of daytime data recovery is ongoing.
  • Patching NICER (17 Jan 2025)
    During EVA 91 on January 16, 2025, ISS Astronaut Nick Hague successfully installed 9 patches into 8 of the NICER XTI sunshades to mitigate light leaks from damaged portions of the optical blocking filters. You can watch a recording of the NICER portion of the spacewalk activity from Nick Hague's helmet-camera.
  • NICER AO7 Selected Proposals and Targets (11 Jan 2025)
    The proposal selection process for Cycle 7 of the General Observer program is complete, and lists of selected proposals and approved targets are available.
  • EVA to repair NICER Scheduled for January 16 (10 Jan 2025)
    Astronauts onboard the ISS will perform an EVA planned for January 16 during which the light leak in NICER's X-ray Timing Instrument will be repaired by applying patches to NICER's sunshades above damaged areas of the thermal films. These patches will reduce optical light and allow NICER's X-ray detectors to perform as intended during orbit day. The repair is scheduled to begin around 9:40am EST, and last about an hour. Please see the description of the EVA on NASA's science website for more details.
  • Joint NICER/IXPE Analysis Workshop (01 May 2024)
    The 2024 Joint NICER/IXPE Workshop will be held at The George Washington University in Washington D.C from Monday, 29th of July, 2024 to Thursday, 1st of August, 2024. Registration is free for both in-person and remote attendees

[More NICER News]