The Japan Aerospace Exploration Agency (JAXA) said Sunday it has experienced trouble communicating with a newly launched X-ray astronomy satellite since Saturday afternoon, making it difficult for the agency to ascertain its condition.

The Hitomi satellite, which was called the Astro-H until its successful launch on a Japanese rocket in mid-February, could be experiencing a power shortage after an unexpected shift in its position may have rendered it unable to draw on solar power, it said.

The satellite is supposed to be orbiting about 580 km (360 miles) above the Earth's surface, but JAXA said the satellite may also have deviated from its intended path.

The agency is trying to re-establish communications with the satellite, but if the situation persists, it will be unable to start astronomy observations, scheduled to begin during the summer. The agency was calibrating equipment on the satellite when it ran into problems.

"We are taking this situation very seriously," Saku Tsuneta, director of the agency's Institute of Space and Astronautical Science, said at a news conference, adding that he does not know at this point whether a communication link can be re-established.

The Hitomi, jointly developed by JAXA, NASA and other concerns, is a space observatory instrument equipped with four X-ray telescopes and two gamma-ray detectors.

Scientists hope data obtained from the satellite will shed light on the mysteries surrounding the evolution of the universe and of black holes, which are difficult to observe directly because they emit no light.

The satellite was launched on Feb. 17 on an H-2A rocket from a space center in Kagoshima Prefecture.