LOFT, the Large Observatory For X-ray Timing


LOFT, the Large Observatory For X-ray Timing, is a proposed space mission intended to answer fundamental questions about the motion of matter orbiting close to the event horizon of a black hole, and the state of matter in neutron stars.
LOFT was in 2011 selected by ESA as one of the four space missions concepts of the Cosmic Vision program that will compete for a launch opportunity at the start of the 2020s.
The LOFT payload module will host two instruments: the Large Area Detector (LAD) and the Wide Field Monitor (WFM).
The LAD will improve upon the effective area of the largest area X-ray instrument ever flown (the Rossi X-ray Timing Explorer's Proportional Counter Array) by a factor of about 20. The improved energy resolution (better than 260 eV) of the LAD will allow the exploitation of spectral diagnostics of relativistically-broadened 6-7 keV (Fe-K) lines, in particular. It will be deployed through a mechanism based on that used for Synthetic Aperture Radar missions, such as the Soil Moisture and Ocean Salinity (SMOS) mission, where very large panels are deployed in space with high accuracy.
The Wide Field Monitor (WFM) will discover and localise X-ray transients and impulsive events and monitor spectral state changes with unprecedented sensitivity. Targeted follow-up observations will make this resource important in its own right.
DTU Space is heading the european team planning to provide the Wide Field Monitor instrument.
Effective start/end date15/02/2011 → …


  • X-ray sources, neutron stars, black holes, Galactic Center
  • ESA