September 30, 2016

Launch of Japanese X-ray observatory postponed

Ground crews prepare the Astro-H spacecraft for launch at the Tanegashima Space Center in Japan. Credit: JAXA
Ground crews prepare the Astro-H spacecraft for launch at the Tanegashima Space Center in Japan. Credit: JAXA

The Japanese space agency said Thursday the launch of an X-ray astrophysics observatory is postponed from Friday due to a poor weather forecast at the Tanegashima Space Center in southern Japan.

The Astro-H mission is awaiting launch aboard a Japanese H-2A rocket to begin a three-year mission observing black holes and measuring the structure of the universe with better precision than ever before.

Led by the Japanese space agency — JAXA — with contributions from NASA, Europe and Canada, Astro-H will peer into regions of space near black holes to see how the immense gravitational tug from the massive objects distort spacetime.

Carrying four instruments and two telescopes, the Astro-H satellite is the sixth in a series of Japanese X-ray missions launched since 1979.

Astronomers will use Astro-H to study how clusters of galaxies — the largest structures in the universe — form and evolve over billions of years. Detections from Astro-H could also help scientists learn about the genesis of heavy elements, such as the carbon and oxygen essential for life, after the Big Bang.

X-ray emissions from the cosmos can only be observed from a satellite in space because Earth’s atmosphere blocks X-ray light from penetrating to the ground.

“We see X-rays from sources throughout the universe, wherever the particles in matter reach sufficiently high energies,” said Robert Petre, chief of the X-ray Astrophysics Laboratory at NASA’s Goddard Space Flight Center, and the U.S. project scientist for Astro-H. “These energies arise in a variety of settings, including stellar explosions, extreme magnetic fields, or strong gravity, and X-rays let us probe aspects of these phenomena that are inaccessible by instruments observing at other wavelengths.”

Packaged inside the nose cone of a Japanese H-2A rocket, the Astro-H satellite weighs 2.7 metric tons — nearly 6,000 pounds — with a full load of propellant.

The mission was set for liftoff Friday at 0845 GMT (3:45 a.m. EST; 5:45 p.m. Japan Standard Time), but JAXA officials wrote on the agency’s Twitter account the flight was grounded due to poor weather.

The launch range at Tanegashima is reserved for the Astro-H flight through Feb. 29, JAXA said.

When officials give a go for launch, ground crews will wheel the 174-foot-tall (53-meter) rocket from its assembly building to the launch pad at Tanegashima, where the two-stage launcher will be filled with cryogenic liquid hydrogen and liquid oxygen propellants.

The upper stage of the H-2A rocket will deploy Astro-H into orbit more than 350 miles (575 kilometers) above Earth about 14 minutes after liftoff.

Astro-H will then unfurl its power-generating solar panels and extend a telescopic boom carrying two of the observatory’s instruments. Ground controllers will check out the X-ray and gamma ray sensors aboard the spacecraft before putting it into scientific service.

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Follow Stephen Clark on Twitter: @StephenClark1.