BeppoSAX termination and reentry

The BeppoSAX satellite reentered the Earth's atmosphere a few minutes past 10pm (word time UTC) on April 29, 2003, exactly seven years minus one day after it was launched from Cape Canaveral (Florida) with an Atlas-Centaur rocket. Reentry occurred roughly 200 miles northwest of the Galapagos Islands. About half the spacecraft weight was anticipated to survive the uncontrolled reentry. For details, see the web site of the Italian Space Agency ASI.

In-orbit operations with BeppoSAX were terminated a year before. Although the scientific payload still functioned perfectly, the orbit of the satellite and the condition of the batteries degraded up to a point where planning of astronomical observations became too cumbersome and the investment return too unfavorable. Therefore, after finishing all requested observations, the spacecraft underwent a deactivition procedure following internationally determined regulations, which on April 30, 2002, brought it in a configuration that ensures the safest possible reentry into the earth atmosphere.

BeppoSAX was built in a collaboration between Italy and the Netherlands. The Dutch scientific contribution consists of two Wide Field Cameras. These cameras are unique to astrophysical X-ray research in the sense that they combine a large field of view with a high angular resolution. This, and the equatorial orbit of the spacecraft have made BeppoSAX a particularly great success because observations with the Wide Field Cameras performed a pivotal role in establishing that Gamma-Ray Bursts, firstly detected in the late sixties during verification of the test ban treaty on nuclear explosions in the earth atmosphere, are in fact the most energetic explosions after the Big Bang.

During its 6 years of operations, BeppoSAX carried out more than 1100 observations and more than fifty Gamma-Ray Bursts were quickly localized. The Wide Field Cameras discovered 130 new X-ray sources. About half are Gamma-Ray Bursts at cosmological distances and half are X-ray stars inside our own galaxy.

All-sky galactic map of 130 transients X-ray stars discovered with the BeppoSAX Wide Field Cameras during its 1996-2002 mission.

Jean in 't Zand, SRON, April 30, 2003