Meet XRISM, the new high-energy mission that speaks European

The X-Ray Imaging and Spectroscopy Mission (XRISM) is scheduled to launch on a H-IIA rocket from the Tanegashima Space Center in Japan at 02:34 CEST on August 26, 2023. Thanks to the important scientific contribution of the European Space Agency (ESA), the JAXA-NASA probe will be able to observe high-energy celestial objects in X-ray light with extraordinary energy resolution.

🚀❕Next major X-ray mission set to launch on Saturday❕
Named #XRISM (krizz-em), the @JAXA_en mission will transform our understanding of the hottest places in the Universe.
What will XRISM discover, and how has @ESA contributed?
👉https://t.co/WHRi9SaupM pic.twitter.com/P1olZctDLA

— ESA Science (@esascience) August 21, 2023

Uncovering the “big things” in the Universe

The main objects of this scientific investigation are the largest in space, the galaxy clusters. These Universe’s building blocks contain gas so hot that they emit X-rays. By collecting their emissions, XRISM will obtain a lot of information about their velocity and energy level. This data will enable scientists to measure the overall mass of these systems and reveal new perspectives on the evolution of the Universe.

On a different scale, other huge objects that emit high-energy radiation are the Active Galactic Nuclei (AGN), the supermassive black holes at the center of many galaxies. XRSIM instruments will provide clues to the emissions of the material around them, accelerated by the enormous force of gravity and partially ejected outside. These measurements will allow scientists to study how AGNs affect the growth rate of stars in the galaxy.

Adding ESA to XRISM’s collaboration formula

The European contributions to the project are, first of all, scientific.

“ESA and the European community have a history of involvement in JAXA’s high-energy space telescopes”, says Matteo Guainazzi, ESA project scientist for XRISM.

The European high-energy astronomical community was deeply involved in the definition of scientific objectives for the mission, also providing the list of objects for the instrument calibration phase.

ESA is also collaborating on spacecraft hardware. The main components that speak “European” are:

• the star tracker, a key component to know where the spacecraft is pointing;
• two geomagnetic aspect sensors and three magnetic torquers, to orientate the spacecraft;
• the heat pipes of Resolve, the main scientific instrument, and its filter wheel mechanism.

It’s time for the launch countdown

An H-IIA 202 rocket built by Mitsubishi Heavy Industries will send the probe into Low Earth Orbit, where it will stay at an altitude of 550 km with an inclination of 31.0°.

Once the spacecraft has reached its destination orbit, it will enter the six-month Performance Verification Phase, during which it will observe the target objects defined by the XRISM Scientific Team. Then, the “normal” science will begin with the observation of objects selected by the scientific community of participating countries and guest observers.

The three-year-long mission will end when the liquid helium onboard will lose its cryogenic properties to cool the Resolve’s instrumentation at its very low operational temperature.