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ORFEUS-SPAS, Tubingen Ultraviolet Echelle Spectrometer (TUES)

NSSDCA ID: 1996-065B-01

Mission Name: ORFEUS-SPAS II
Principal Investigator:Dr. Michael Grewing


The Tubingen Ultraviolet Echelle Spectrometer (TUES) was also known as the Far Ultraviolet (FUV) Spectrometer. TUES operated in the 90 - 125 nm range with a resolving power of R = 10,000.

Light coming into the ORFEUS 1-m telescope was deflected into TUES by a movable mirror. When the mirror was moved out of the beam, light fell onto a second spectrometer - the Berkeley Extreme and Far-UV Spectrometer (BEFS). TUES consisted of an Echelle blazed grating of 316 lines per millimeter, a cross disperser grating of 1200 lines per millimeter, and a high-sensitive photon counting and imaging detector with a sensitive area of 40mm x 40mm.

TUES returned about 239 spectra of 62 targets during the ORFEUS-SPAS II mission. TUES failed to record scientifically usable data during the ORFEUS-SPAS I mission.

Alternate Names

  • ORFEUS-SPASII/ORFEUS-SPAS,TubingenUltravioletEchelleSpectrometer_TUES_

Funding Agency

  • German Space Agency (Germany)


  • Astronomy: Ultraviolet

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. Michael GrewingPrincipal InvestigatorUniversitat Tubingen
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