Japan’s X-ray Astronomy Satellite ASTRO-H (Hitomi). Credit: JAXA

Japan’s X-ray Astronomy Satellite ASTRO-H (Hitomi).
Credit: JAXA

The recent loss of Japan’s X-ray Astronomy Satellite ASTRO-H (Hitomi) is a blow to acquiring new space-based views of the universe – but also adds to the growing issue of Earth orbiting debris.

Furthermore, some of the errant 2.7 ton spacecraft is expected to reach terra firma when it eventually makes it fiery fall through the atmosphere.

Castaway panels

Credit: JAXA

Credit: JAXA

The Japan Aerospace Exploration Agency’s (JAXA) ASTRO-H was boosted into space on February 17, 2016 (JST) from the Tanegashima Space Center. But late last month, after emergency attempts to salvage the craft, JAXA declared the mission lost to space.

“Most of our analyses including simulations on the mechanisms of object separation, it is highly likely that both solar array paddles had broken off at their bases where they are vulnerable to rotation,” a JAXA statement notes.

Pre-launch photo of ASTRO-H. Credit: JAXA

Pre-launch photo of ASTRO-H.
Credit: JAXA

“Accordingly, JAXA will cease the efforts to restore ASTRO-H and will focus on the investigation of anomaly causes. We will carefully review all phases from design, manufacturing, verification, and operations to identify the causes that may have led to this anomaly including background factors,” JAXA states.

State of the art instruments

Equipped with four state of the art instruments, ASTRO-H was built to eye the hot and energetic universe.

The word “Hitomi” generally means “eye” — and specifically the pupil, or entrance window of the eye — the aperture, according to JAXA background information on the spacecraft.

ASTRO-H was the sixth satellite in a series of highly successful X-ray astronomy missions initiated by the Institute of Space and Astronautical Science (ISAS) JAXA.

Debris survival

So round and round it goes, and where Hitomi will fall is far from predictable.

Credit: JAXA

Credit: JAXA

Inside Outer Space asked JAXA for a statement on when the spacecraft will plunge to Earth – and any expected debris survival.

“The reentry time period for X-ray Astronomy Satellite ASTRO-H

(Hitomi) is expected within 25 years,” responded Izumi Yoshizaki of JAXA’s Public Affairs Department.

“Pre-launch analysis/modeling of the spacecraft’s reentry and survivable hardware that could land on Earth was done,” Yoshizaki said. The RCS (Reaction Control System) tank made of titanium is expected to survive during the reentry.”

Reentry window?

However, the “within 25 years” means more analysis of the object’s reentry time would be helpful.

According to satellite tracker extraordinaire, Ted Molczan of Canada, he estimates that ASTRO-H will remain in orbit for at least a few years.

Shortly after launch, ASTRO-H is cast off into Earth orbit. Credit: JAXA

Shortly after launch, ASTRO-H is cast off into Earth orbit.
Credit: JAXA

Scott Hull, an orbital debris engineer at NASA’s Goddard Space Flight Center adds that, in addition to the very unfortunate loss of a valuable science asset, any breakup is of concern to the orbital debris community as potential threat to other spacecraft.

“It is somewhat fortunate that most of the secondary objects from this breakup are considered relatively small, and in general their orbits are already decaying, reducing the duration of any threat. Apparently one debris object has already reentered,” Hull told Inside Outer Space.

One arguable question is whether the dead hulk of Hitomi might make it a candidate for a debris removal experiment?

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