
A few hours ago, the Japanese XRISM space telescope and the SLIM Moon lander were launched from the Tanegashima space center atop an H-IIA rocket. After just over 14 minutes, XRISM separated from the rocket’s last stage and after about 48 minutes, SLIM did the same. XRISM will reach low Earth orbit, where it will position at an altitude of approximately 550 kilometers. SLIM started a much longer journey.
The XRISM (X-Ray Imaging and Spectroscopy Mission) space telescope is considered the successor of ASTRO-H/Hitomi, which was lost following an anomalous behavior of its onboard systems. It’s equipped with instruments that are different from Hitomi’s not only due to the technological evolution that happened over the years but also due to a change of goals. This new project was carried out in collaboration with NASA and with contributions from ESA.
After the start of the project that led to the construction of Hitomi, NASA built and launched its NuSTAR space telescope, specializing in so-called hard X-rays. For this reason, XRISM will focus on the detection of so-called soft X-rays with the Resolve spectrometer and the Xtend camera, both connected to actual telescopes.
The Resolve instrument operates at temperatures close to absolute zero, so it uses cryogenic technology that limits its useful life to approximately three years. After the liquid helium used for cooling Resolve runs out, the Japanese space agency JAXA will assess over time which uses can still be made at higher temperatures.
Making breakthroughs in X-ray astronomy is the goal of the XRISM space telescope. Cosmological mysteries such as the formation of galaxy clusters, the production and distribution of chemical elements, and the search for the missing baryonic matter will also be investigated with XRISM. The instrument calibration phase will be long since it’s expected to last about ten months.

SLIM (Smart Lander for Investigating Moon) is a small Moon lander with a mass of about 590 kg designed as a trailblazer for future explorations of the Moon. It aims to demonstrate Moon landing technologies accurately and offer advances in the study of the Moon, and in the future also other planets and moons, using small exploration systems.
The SLIM lander will arrive on the Moon only after completing a long series of maneuvers. For this reason, only in late 2023 will JAXA announce a date for the Moon landing attempt depending on course adjustments that will be needed. The point of this choice is to use a route that makes optimal use of fuel.
