The Rossi X-ray Timing Explorer was a NASA mission that was used to investigate bright cosmic X-ray sources by observing how their X-ray intensities change over a broad range of timescales from milliseconds to years. Three instruments designed to perform the observations were carried into space on a spacecraft that was launched in December, 1995, and that operated until January, 2012.

The development, operation, and data analysis of one of the instruments, the All-Sky Monitor, was overseen and, to a large extent, carried out by a Center for Space Research, now Kavli Institute, team.  This team also led the effort to develop and operate an Experiment Data System that was a special-purpose computer that compressed the data produced by the All-Sky Monitor and the Proportional Counter Array so that it would be able to be telemetered to the ground.  Though the mission is no longer operating, the data and results continue to be relevant to a wide range of aspects of x-ray sources, and especially to the physics and astrophysics of close binary systems comprising a neutron star or stellar-mass black hole together with a normal-type star.  More information may be obtained from NASA’s Goddard Space Flight Center’s RXTE web site and the MIT Kavli Institute RXTE web site.