Rossi X-ray Timing Explorer

The Rossi X-ray Timing Explorer (RXTE) was a NASA satellite that observed the time variation of astronomical X-ray sources, named after physicist Bruno Rossi. The RXTE had three instruments — an All-Sky Monitor, the High-Energy X-ray Timing Experiment (HEXTE) and the Proportional Counter Array. The RXTE observed X-rays from black holes, neutron stars, X-ray pulsars and X-ray bursts. It was funded as part of the Explorer program and was also called Explorer 69.

RXTE had a mass of 3,200 kg (7,100 lb) and was launched from Cape Canaveral on 30 December 1995, at 13:48:00 UTC, on a Delta IIlaunch vehicle. Its International Designator is 1995-074A.