The Japan Aerospace Exploration Agency (JAXA) and Mitsubishi Heavy Industries, Ltd. successfully launched the X-ray Astronomy Satellite (ASTRO-H) at 5:45 p.m. (0845 GMT) on Wednesday 17th February.

Following separation from the launch rocket having attained the correct orbital height and speed,  and deployment of the solar panels, Astro-H has been renamed Hitomi at the start of its three-year mission.

The Hitomi satellite is the sixth in a series of Japanese X-ray missions since 1979 and is the successor to the SUZAKU satellite currently in space. 

Hitomi will study X-rays from clusters of galaxies and the supermassive black holes at the centre of galaxies, enabling scientists to investigate the nature and influence of dark matter, dark energy and the physics of extreme gravitational fields.

With an overall length of about 14 meters and total weight of 2.7 tons, Hitomi is equipped with four telescopes and six detectors to collect both hard and soft X-rays and gamma rays. The four telescopes include a soft X-ray spectrometer (SXS), a soft X-ray imaging system (SXI), a hard X-ray imaging system (HXI), and a soft gamma-ray detector (SGD).

Led by Japan, the JAXA’s project is an international collaboration with the participation of U.S. National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), Canadian Space Agency (CSA), Netherlands Institute for Space Research, and universities in Japan, Europe and North America.

Prof Andy Fabian, who leads the X-ray group at the Institute of Astronomy, has been a lead scientific advisor for many years on this mission, and many of the X-ray astronomers at the IoA expect to benefit from the new observations that Hitomi will carry out.