Wikipedia

Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph

Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph (FGS-NIRISS) is an instrument on the James Webb Space Telescope (JWST) that combines a Fine Guidance Sensor and a science instrument, a near-infrared imager and a spectrograph.[1] The FGS/NIRISS was designed by the Canadian Space Agency (CSA) and built by Honeywell[2] as part of an international project to build a large infrared space telescope with the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA).[1] FGS-NIRISS observes light from the wavelengths of 0.8 to 5.0 microns.[1] The instrument has four different observing modes.[3]

FGS/NIRISS ETU, 2016
FGS Test unit undergoes cryogenic testing, 2012
Infographic of JWST instruments and their observation ranges of light by wavelength

Physically the FGS and NIRISS are combined, but optically they are separate with the FGS being used by the telescope to point it, whereas NIRISS is an independent science instrument.[3][4] The spectroscopic mode is capable of doing exoplanet spectroscopy.[5] The detector for NIRISS is a 2048 × 2048 pixel mercury cadmium telluride (HgCdTe) array, where each pixel is 18 microns on a side according to the STSCi.[6] The field of view is 2.2' × 2.2' which gives a plate scale of about 0.065 arcsec/pixel.[6]

The FGS will help the telescope aim and stay pointed at whatever it is commanded to look at.[7] FGS helps provide data to the JWST Attitude Control System (ACS) and to do this it has a big sky coverage and sensitivity, to give a high probability it can find a guide star.[8]

NIRISS is designed for performing:[9][10]

The aperture masking interferometry mode uses a seven-hole aperture masking disc, and should allow the detection of exoplanets within certain ranges of light and types of stars.[9]

The Engineering Test Unit of the FGS was delivered to NASA in 2010.[11] The flight units were planned to be delivered later after the ETU, which enabled testing with other JWST hardware.[11] The flight units of FGS/NIRISS were delivered to NASA in August 2012.[12]

Commissioning is complete as of the following dates:

  • Single object slitless spectroscopy, 06/22/2022
  • Wide field slitless spectroscopy, 06/14/2022
  • Aperture masking interferometry, 06/14/2022
  • Imaging (parallel only), 06/08/2022

FGS

edit
 
Image produced by the FGS.

The FGS functionality supports JWST pointing at the desired targets. The FGS is designed to find pre-selected guide stars, which allows the telescope to stay precisely pointed at the desired target.[13] The actual pointing of the telescope is handled by other segments, especially the systems in the spacecraft bus and the fine guidance mirror in the Optical Telescope Element.

Tuneable filter (cancelled)

edit

Previously, CSA was working on a tuneable image filter.[14] This device was intended to allow a narrow filter band to be selected (as opposed to a fixed filter band).[14] The TFI was cancelled in 2011 and the work rolled-over into the NIRISS.[15] The TFI would have a selectable filter band between 1.5–5 μm.[16]

In July 2011 the Canadian Space Agency reluctantly discontinued work on the Tunable Filter Imager (TFI) when it became clear that issues associated with the cryogenic operation of its Fabry-Perot etalon were unlikely to be resolved in time to meet the instrument's delivery schedule...

— STSCI[15]

A developmental version of the TFI was tested in Ontario, Canada in 2010.[15] The chief problem was the time needed to resolve issues with cryogenic operation in time for the JWST launch.[15] The TFI was re-configured to form the basis for the NIRISS instrument that is planned for flight on the space telescope.[15]

Labeled diagrams

edit
  • Labeled diagrams
  •  
    NIRISS
  •  
    FGS/NIRISS
  •  
    FGS/NIRISS

Build team

edit

Related institutions and the science team for the instrument includes:[7]

Canada credits work on the FUSE (Far Ultraviolet Spectroscopic Explorer) as helping them prepare for making JWST FGS.[7]

Begoña Vila has been the project's lead systems engineer since 2013.[17]

See also

edit

References

edit
  1. ^ a b c "The James Webb Space Telescope". National Aeronautics and Space Administration. Archived from the original on December 14, 2021. Retrieved November 27, 2016.
  2. ^ "Canada's role in Webb". Canadian Space Agency. 18 February 2011. Archived from the original on 16 January 2024. Retrieved 7 March 2022.
  3. ^ a b Doyon, René; Hutchings, John B.; Beaulieu, Mathilde; Albert, Loic; Lafrenière, David; Willott, Chris; Touahri, Driss; Rowlands, Neil; Maszkiewicz, Micheal; Fullerton, Alex W.; Volk, Kevin; Martel, André R.; Chayer, Pierre; Sivaramakrishnan, Anand; Abraham, Roberto; Ferrarese, Laura; Jayawardhana, Ray; Johnstone, Doug; Meyer, Michael; Pipher, Judith L.; Sawicki, Marcin (22 August 2012). Clampin, Mark C; Fazio, Giovanni G; MacEwen, Howard A; Oschmann, Jacobus M (eds.). The JWST Fine Guidance Sensor (FGS) and Near-Infrared Imager and Slitless Spectrograph (NIRISS). Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave. Vol. 8442. SPIE. pp. 84422R. Bibcode:2012SPIE.8442E..2RD. doi:10.1117/12.926578. S2CID 120702854.
  4. ^ "Webb's Instruments".
  5. ^ "ESA Science & Technology: The JWST instrument suite". sci.esa.int. ESA. Archived from the original on 27 December 2023. Retrieved 27 November 2016.
  6. ^ a b "NIRISS: Near-InfraRed Imager and Slitless Spectrograph". stsci.edu. Archived from the original on February 3, 2014. Retrieved 2016-11-27.
  7. ^ a b c "Canada's Contribution to the James Webb Space Telescope – Canadian Space Agency". asc-csa.gc.ca. Archived from the original on 2016-11-27. Retrieved 2016-11-27.
  8. ^ "FGS – Fine Guidance Sensor". stsci.edu. Space Telescope Science Institute. Archived from the original on 11 December 2016. Retrieved 27 November 2016.
  9. ^ a b "JWST Near Infrared Imager and Slitless Spectrograph - JWST User Documentation". jwst-docs.stsci.edu. Retrieved 14 March 2022.
  10. ^ "JWST Pocket Guide January 2022" (PDF). stsci.edu. Space Telescope Science Institute. Archived (PDF) from the original on 10 June 2023. Retrieved 14 March 2022.
  11. ^ a b Chandler, Lynn; Chicone, Ruth Ann (8 September 2010). "NASA Goddard Receives the Webb Telescope's Guiding Light from Canada" (Press release). NASA & CSA. Goddard 10-077. Archived from the original on 22 December 2010.
  12. ^ Gutro, Rob (13 August 2012). "Second Flight Instrument Delivered for James Webb Space Telescope". www.nasa.gov. NASA. Archived from the original on 15 August 2012.
  13. ^ "JWST Fine Guidance Sensor - JWST User Documentation". jwst-docs.stsci.edu. Space Telescope Science Institute. Archived from the original on 29 September 2023. Retrieved 14 March 2022.
  14. ^ a b Sabelhaus, Phillip A. (1 June 2004). An Overview of the James Webb Space Telescope (JWST) Project. SPIE. NASA. SPIE-5487-21. Archived from the original on 24 January 2024 – via ntrs.nasa.gov.
  15. ^ a b c d e "Tunable Filter Imager (TFI)". Space Telescope Science Institute. Archived from the original on 4 June 2010.
  16. ^ Doyon, R.; Hutchings, J.; Rowlands, N.; Evans, C. E.; Greenberg, E.; Haley, C.; Scott, A. D.; Touahri, D.; Beaulieu, M.; Lafrenière, D.; Abraham, R.; Barton, E.; Chayer, P.; Ferrarese, L.; Fullerton, A. W.; Jayawardhana, R.; Johnstone, D.; Martel, A.; Meyer, A. W. M. R.; Pipher, J.; Saad, K.; Sawicki, M.; Sivaramakrishnan, A.; Volk, K. (16 July 2010). "The JWST tunable filter imager (TFI)". In Oschmann, Jr, Jacobus M; Clampin, Mark C; MacEwen, Howard A (eds.). Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave. Vol. 7731. pp. 77310F. doi:10.1117/12.857382. S2CID 122033089. Retrieved 14 March 2022.
  17. ^ Sacristán, Enrique (22 August 2016). "La NASA premia a una astrofísica gallega por su trabajo en el mayor telescopio espacial" [NASA Awards a Galician Astrophysicist for Her Work on the Largest Space Telescope]. El Confidencial (in Spanish). Archived from the original on 19 April 2023. Retrieved 31 May 2019.
edit
Retrieved from "https://en.wikipedia.org/w/index.php?title=Fine_Guidance_Sensor_and_Near_Infrared_Imager_and_Slitless_Spectrograph&oldid=1247758401"