El satélite argentino de observación astronómica SAC-B se lanzó en 1996 (antes que el SAC-A). Tenía por objetivo de investigar las fuentes explosivas extragalácticas de alta energía. Su peso era de 191 kg, (50 kg de carga útil). Fue puesto en órbita montado en el cohete estadounidense Pegasus XL apodado Maggie. Debido a fallas en el vehículo lanzador no pudo ser desacoplado del mismo.

International Participation

SAC-B was carried out as an international cooperative project between the National Commission on Space Activities (CONAE), Argentina, and the National Aeronautics and Space Administration (NASA), USA.


CONAE was responsible for the design and construction of the SAC-B satellite and the Institute of Astronomy and Space Physics (IAFE) provided one scientific instrument, the Hard X-Ray Spectrometer (HXRS).


NASA provided two scientific instruments and launch services on a Pegasus XL vehicle. The scientific instruments were: the Goddard X-Ray Experiment (GXRE) provided by Goddard Space Flight Center (NASA) and Cosmic Unresolved X-Ray Background Instrument using CCDs (CUBIC) provided by la Penn State University.


Argentina has established separate agreements with the Italian Space Agency (ASI) in providing the solar arrays of Gallium Arsenide (GaAs) cells plus a scientific instrument, the Imaging Particle Spectrometer for Energetic Neutral Atoms (ISENA).


The Brazilian National Institute on Space Research (INPE) in providing the facilities for the system qualification tests of SAC-B.