The primary goals are the determination of the equation of state of matter at supra-nuclear density, the measurement of QED effects in highly magnetised stars, and the study of accretion in the strong-field regime of gravity. Primary targets include isolated and binary neutron stars, strong magnetic field systems like magnetars, and stellar-mass and supermassive black holes.

The mission carries a unique and unprecedented suite of state-of-the-art instruments enabling for the first time ever the simultaneous spectral-timing-polarimetry studies of cosmic sources in the energy range from 0.5 to 30 keV.

In its original configuration, this Chinese X-ray satellite included four instruments: two led by China (IHEP/CAS) and two by Europe (INAF and ICE-CSIC), with Margarita Hernanz as PI of the European Wide Field Monitor (WFM). However, there was a de-scoping of eXTP in February 2024 aimed to remove programmatic uncertainties, and now only the two Chinese instruments SFA (Spectral Focusing Array) and PFA (Polarimetry Focusing Array) are kept onboard.

Since 2014, there has been a very relevant Spanish participation led by ICE-CSIC, at the level of PI of the WFM, as ICE-CSIC would provide the collimator, the coded mask assembly and the mechanical support of the detector assemblies for all the WFM cameras, plus the mechanical and thermal configuration of the whole WFM. The institute would have been responsible of the Assembly, Integration, Verification and Test of the WFM cameras as well. During 2025, the centre continued the development of the Demonstration Model of a whole WFM camera, in collaboration with the Spanish industries Sener and Tecnalia. In addition, they continued working on the design optimisation, mechanical simulations, manufacturing of the coded mask and other structural parts, like the detectors support plate and the collimator (among others), as well as the assembly and very precise alignment of a whole WFM camera.

Currently, the institute keeps contributing scientifically to the mission, and has participated both in the eXTP international collaboration meeting in February 2025, in Beijing (China), and in the eXTP scientific workshop in August 2026 in Turku (Europe).

Former configuration of eXTP, including Europe-led instruments LAD and WFM. Credits: eXTP.