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The purpose of the ORFEUS-SPAS I mission was to conduct investigations of celestial sources in the far and extreme ultraviolet spectral range. Specific objects targeted included the atmospheres of hot stars and the coronae of cool stars. Narrow interstellar absorption lines were studied to further understanding of the interstellar medium (ISM). ORFEUS-SPAS I was the first of a series of planned joint DARA (German Space Agency) /NASA missions. The name arises from the reusable Astro-Shuttle Pallet Satellite (Astro-SPAS), and the Orbiting Retrievable Far and Extreme Ultraviolet Spectrometers (ORFEUS) Telescope carried on Astro-SPAS.

ORFEUS-SPAS was a free-flying platform designed to be deployed and retrieved from the space shuttle. The Astro-SPAS carrier was powered by batteries, and data from the instruments were stored on tape. Absolute pointing was accurate to within a few arc seconds. ORFEUS-SPAS is 4.5m length and has a 2.5m width base. Operation of ORFEUS-SPAS was approximately 40km from the shuttle.

ORFEUS-SPAS carried three spectrometers operating over the wavelength range 400 - 1250 Angstroms. The Tubingen Ultraviolet Echelle Spectrometer (TUES) and the Berkeley Extreme and Far-UV Spectrometer (BEFS) were housed on the primary instrument - the ORFEUS 1-m telescope. The Interstellar Medium Absorption Profile Spectrograph (IMAPS) was operated independently from ORFEUS.

The ORFEUS-SPAS I mission was flown in September 1993.

Alternate Names

  • SPAS
  • STS 51/SPAS
  • 22798

Facts in Brief

Launch Date: 1993-09-12
Launch Vehicle: Shuttle
Launch Site: Cape Canaveral, United States
Mass: 3500.0 kg

Funding Agencies

  • NASA-Office of Space Science Applications (United States)
  • German Space Agency (Federal Republic of Germany)


  • Astronomy

Additional Information

Questions or comments about this spacecraft can be directed to: Coordinated Request and User Support Office.



NameRoleOriginal AffiliationE-mail
Dr. C. Stuart BowyerMission Principal InvestigatorUniversity of California,
Dr. Klaus SteinbergProject ManagerDeutsche Agentur fur
Dr. Gerhard KramerProject ScientistUniversitat Tubingen 
Dr. Immo AppenzellerMission
Dr. Michael GrewingMission Principal InvestigatorUniversitat Tubingen 
Dr. D.-R. SchmittProject EngineerDeutsche Forschungsenstalt fuer Luft-und Raumfahrt 
Mr. R. Wayne RichieProject ManagerNASA Headquarters 
Dr. Robert N. StachnikProject ScientistNASA Headquarters 
Dr. Edward B. JenkinsMission Principal InvestigatorPrinceton
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