Einstein Probe Mission Overview

Mission Overview

The Einstein Probe (EP) is a mission of the Chinese Academy of Sciences (CAS), in collaboration with the European Space Agency (ESA) and the Max Planck Institute for extraterrestrial Physics (MPE), Germany, dedicated to time-domain high-energy astrophysics. Its primary goals are to discover high-energy transients and monitor variable objects. To achieve this, EP employs a very large instantaneous field-of-view (3600 square degrees), along with moderate spatial resolution (FWHM ~5 arcmin) and energy resolution in the 0.5-5 keV energy band. EP has also the capability of performing fast and deep follow-up observations in the 0.3-10 keV energy band (effective area 2*300 cm2 @ 1 keV; half-power diameter, HPD, ~30 arcsec), as well as of quick downlink of transient alert messages. The launch date is currently foreseen for late 2023.


The above requirements can be fulfilled by wide-field X-ray focusing optics, i.e., lobster-eye Micro-Pore Optics (MPO), whose focusing imaging results in a greatly enhanced gain in signal to noise, and hence high detecting sensitivity. EP carries a Wide-field X-ray Telescope (WXT) with a large instantaneous FoV, which adopts such a novel lobster-eye MPO technology.  Complementary to this wide-field instrument is a Follow-up X-ray Telescope (FXT) with a large effective area and a narrow field-of-view.

Further information about the 2 instruments:

Lobster Eye Imager for Astronomy (LEIA)

LEIA is one of the experimental instruments aboard the SATech-01 satellite of the CAS. It is a fully representative test model of one of the 12 identical modules of EP-WXT. SATech-01 was launched on 27 July 2022. It is in a Sun-synchronous near-Earth circular orbit with a period of 95 minutes and has a designed lifetime of 2 years. Further information can be found at the LEIA webpages at NAOC, China.

ESA contribution to Einstein Probe

  • Develop, qualify and provide to CAS Mirror Assembly and Electron Diverter of FXT
  • Provide support to CAS in testing & calibration of detectors and optical elements of WXT 
  • Provide support to data download from EP spacecraft through ESA’s Ground Stations

CAS-ESA-MPE collaboration workshops