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The objective of this mission was to perform spectroscopic X-Ray astronomy in the wavelength band 1--12 KeV, with particular emphasis on spectroscopy of the iron K band. Another objective of ASCA was imaging of the structure of extended sources such as clusters of galaxies and supernova remnants. ASCA carried four identical telescopes with a total effective area of 1300 cm**2 at 1 KeV and 600 cm**2 at 6--7 KeV. ASCA was a cooperative mission between Japan (ISAS) and NASA. NASA provided four conical grazing incidence, multilayer thin foil mirrors. Two CCD-based detectors were provided by MIT. Japan provided the imaging gas scintillation proportional counters (IGSPC), the spacecraft, the launch vehicle, and a ground station. In return for its scientific instrument contribution, NASA was allocated 15% of the observing time after the initial seven or eight month Performance Verification (PV) period. In addition, 25% of the observing time was set aside for collaborative proposals between US and Japanese scientists.

The satellite was launched on February 20, 1993. A solar flare on 14 July 2000 caused heating and expansion of the upper atmosphere, which increased the drag and external torque on ASCA. The attitude was perturbed, so the solar panels lost lock on the Sun, resulting in discharge of the batteries. ASCA reentered the atmosphere on March 2, 2001.

Alternate Names

  • Asuka
  • Astro-D
  • 22521

Facts in Brief

Launch Date: 1993-02-20
Launch Vehicle: M-3SII
Launch Site: Uchinoura Space Center, Japan
Mass: 420.0 kg
Nominal Power: 602.0 W

Funding Agencies

  • National Aeronautics and Space Administration (United States)
  • Institute of Space and Aeronautical Science, U of Tokyo (Japan)


  • Astronomy

Additional Information

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



NameRoleOriginal AffiliationE-mail
Prof. Yasuo TanakaProject ScientistInstitute of Space and Aeronautical Science 
Dr. Guenter R. ReiglerProject ManagerNASA
Dr. Stephen S. HoltProject ScientistNASA Goddard Space Flight
Mr. Jerre B. HartmanProject ManagerNASA Goddard Space Flight
Dr. Nicholas E. WhiteDeputy Project ScientistNASA Goddard Space Flight
Dr. Alan N. BunnerProgram ScientistNASA Headquarters 

Selected References

Tanaka, Y., The ASTRO-D mission, In--Observatories in Earth Orbit and Beyond, edited by Y. Kondo, IAU Colloq. 123, Kluwer, 81-87, 1990.

US Active Archive for ASCA Information/Data

The ASCA Archive at HEASARC

Other Sources of ASCA Information/Data

Japan ASCA Data Archive at ISAS
ASCA mission page at ISAS
The UK ASCA Data Archive at Leicester

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