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Mission Overview

Map of Observations

L-band map showing most of the sky, strongest in the Galaxy.

Wavelength Coverage

Wavelength coverage from 900 to 1710 Angstroms.

FIMS-SPEAR conducted the first large-area spectral imaging survey of the far-ultraviolet sky, a band that spans warm and hot plasma cooling lines, molecular hydrogen fluorescent emission, and dust-scattered starlight. Known in Korea as the "Far-Ultraviolet Imaging Spectrograph" (FIMS) and in the US as "Spectroscopy of Plasma Evolution from Astrophysical Radiation" (SPEAR), FIMS-SPEAR was the primary payload on STSAT-1, Korea's first astronomy satellite.

This mission comprised dual imaging spectrographs optimized for measuring diffuse emission, including the "Short" S-band (900–1150 Å) and the "Long" L-band (1350–1710 Å). Available data products include hyperspectral imaging covering most of the sky, extracted line emission maps, star spectra, and pointed observations of the Vela supernova remnant.

FIMS-SPEAR was a joint mission between the Korean Astronomy and Space Science Institute (KASI), the Korea Advanced Institute of Science and Technology (KAIST), and the University of California, Berkeley, with support from NASA and the Korean Ministry of Science and Technology.

Active From

September 2003 - November 2004


  • Spectral resolving power R~550
  • Spatial resolution down to 5 arcmin (7 arcmin in available products)


  • Imaging spectroscopy

Latest Updates

  • 14 April 2023: v1.0 released

Data Access

  • Direct Download

    Direct download links

    All FIMS-SPEAR products can be retrieved through direct download links, bundles, and cURL scripts tabulated in the mission manual.

  • MAST Portal

    MAST Portal.

    A subset of FIMS-SPEAR data, including Vela supernova remnant emission line images and 209 bright star spectra, are discoverable through the MAST Portal. Search for bright stars by coordinate, or discover other missions' observations of your target.

  • MAST Astroquery

    MAST Astroquery example.

    A subset of FIMS-SPEAR data, including Vela supernova remnant emission line images and 209 bright star spectra, can also be retrieved programmatically using mast.astroquery.



Image of the Vela supernova remnant


The FIMS-SPEAR manual, including mission documentation, MAST data access information, tutorials, and more.

Image Gallery


A short rectangular prism sits on a table, partially encased in gold-colored metal, with the wires inside visible.

The FIMS-SPEAR instrument prior to launch.

A small satellite, shorter than a human, with complex tubing and orange metal. Looks like B2EMO.

The STSAT-1 satellite (prior to launch), in which FIMS-SPEAR was the primary payload. STSAT-1, at one point known as KAISTSat-4, was Korea's first astronomy satellite.

A dozen people attach STSAT-1 to a part of the launching mechanism.

STSAT-1 is prepared for launch.

Same as the previous image, but now the people are gone.

STSAT-1 waiting for launch.

A schematic of STSAT-1 (labeled KAISTSAT-4) flies in orbit. Below, the Earth's aurora. Above, the galaxies.
Mission Concept

An artist's schematic from early in mission planning. FIMS-SPEAR, inside STSAT-1 (formerly known as KAISTSAT-4), observed both the terrestrial aurora below and the galaxies and stars above.

The instrument sits on a table, exhibiting wires and other complicated components.

The FIMS-SPEAR instrument from another angle.