X-Ray Imaging and Spectroscopy Mission
The X-Ray Imaging and Spectroscopy Mission (XRISM, pronounced "crism"), formerly the X-ray Astronomy Recovery Mission (XARM), is an X-ray space telescope mission of the Japan Aerospace Exploration Agency (JAXA) in partnership with NASA to provide breakthroughs in the study of structure formation of the universe, outflows from galaxy nuclei, and dark matter. As the only international X-ray observatory project of its period, XRISM will function as a next generation space telescope in the X-ray astronomy field, similar to how the James Webb Space Telescope, Fermi Space Telescope, and the Atacama Large Millimeter Array (ALMA) Observatory are placed in their respective fields.
| Names | XRISM ASTRO-H Successor ASTRO-H2 XARM | ||||||
|---|---|---|---|---|---|---|---|
| Mission type | X-ray astronomy | ||||||
| Operator | JAXA | ||||||
| COSPAR ID | 2023-137A | ||||||
| SATCAT no. | 57800 | ||||||
| Website | xrism www | ||||||
| Mission duration | 3 years (planned) ≈5 months and 6 days (in progress) | ||||||
| Spacecraft properties | |||||||
| Spacecraft type | ASTRO | ||||||
| Bus | ASTRO-H | ||||||
| Launch mass | 2,300 kg (5,100 lb) | ||||||
| Start of mission | |||||||
| Launch date | 6 September 2023, 23:42:11 UTC | ||||||
| Rocket | H-IIA 202 | ||||||
| Launch site | Tanegashima Space Center | ||||||
| Contractor | Mitsubishi Heavy Industries | ||||||
| Orbital parameters | |||||||
| Reference system | Geocentric orbit | ||||||
| Regime | Low Earth orbit | ||||||
| Perigee altitude | 550 km | ||||||
| Apogee altitude | 550 km | ||||||
| Inclination | 31.0° | ||||||
| Period | 96.0 minutes | ||||||
| Main telescope | |||||||
| Name | Soft X-ray Telescope | ||||||
| Diameter | 45 cm (18 in) | ||||||
| Focal length | 5.6 m (18 ft) | ||||||
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X-ray astronomy satellite in Japan | |||||||
The mission is a stopgap for avoiding a potential period of observation loss between the current X-ray telescopes (Chandra and XMM-Newton), and those of the future (Advanced Telescope for High Energy Astrophysics (ATHENA)). Without XRISM, there could be a time period during with no X-ray data was collected. This would arise in the early 2020s as these two reach the end of their missions, due to the loss, in 2016, of the Hitomi X-ray telescope, which was launched to be the follow-on to the Chandra and Newton telescopes.
During its early design phase, XRISM was also known as the "ASTRO-H Successor" or "ASTRO-H2". After the loss of Hitomi, the name XARM was used, the R in the acronym referring to recovering the ability to do X-ray spectroscopy. The name changed to XRISM in 2018 when JAXA formally initiated the project team.