Just outside his cluttered office, Hiroya Yamaguchi stands in front of a blackboard covered with diagrams and notes related to the X-Ray Imaging and Spectroscopy Mission, known as XRISM. This space telescope, launched on September 6, 2023, carries high expectations following previous issues with JAXA’s Suzaku and Hitomi telescopes. Despite these challenges, XRISM has been generating valuable data since its first light in January, uncovering unexpected discoveries.
However, a problem persists with the telescope’s aperture door, preventing low-energy X-rays from reaching the detector. While attempts to open the door have failed, discussions are ongoing between NASA and JAXA on the best path forward to operate XRISM. The decision to temporarily operate the spacecraft without opening the door has not been finalized.
X-rays provide a unique perspective on the universe, and XRISM’s Resolve instrument offers detailed insights into the atomic and velocity structure of X-ray sources. The closed door poses a dilemma for scientists, limiting access to certain parts of the X-ray universe. Despite this setback, XRISM continues to deliver impressive results at higher energies.
The gate valve issue raises questions about accessing lower-energy X-rays and the potential for future discoveries. While uncertainties loom over the fate of NASA’s Chandra mission, the field of X-ray astronomy remains optimistic about the future. XRISM’s groundbreaking data opens new possibilities for understanding the cosmos, even as challenges persist in unlocking the telescope’s full capabilities. Excitement abounds for the discoveries that lie ahead, showcasing the resilience and innovation of space exploration.




