Uncommunicative X-ray Satellite Hitomi Tumbles Wildly in Orbit

Summary: Uncommunicative x-ray satellite Hitomi tumbles wildly in orbit and varies in brightness, according to JAXA updates March 27 and March 29.

artist's depiction of ASTRO H X-ray Observatory in orbit: JAXA, CC BY 2.0, via NASA Goddard Scientific Visualization Studio

Uncommunicative X-ray Satellite Hitomi tumbles wildly in orbit, at an altitude of around 350 miles (574 kilometers) above Earth, and displays extreme brightness variations, according to communication anomaly updates Sunday, March 27, and Tuesday, March 29, 2016, by the Japan Aerospace Exploration Agency JAXA.

An update issued March 29 on JAXA website’s X-ray Astronomy Satellite Hitomi page announced the receipt of short signals from the satellite via Japanese and overseas ground stations. Uchinoura Ground Station at Kyushu Island’s southwestern tip received the first signal Monday, March 28, around 10 p.m. Japan Standard Time. Chile’s Santiago Tracking Station reported receipt of the second signal March 29 around 12:30 a.m.

“JAXA has not been able to figure out the state of its health, as the time frames for receiving the signals were very short,” the update stated.

The update also shared the U.S. Joint Space Operations Center’s March 27 report of Hitomi’s separation into five pieces. The report placed Hitomi’s breakup March 26 at around 10:42 a.m. The U.S. Joint Space Operations Center (JSpOC) surveys and identifies artificial objects orbiting Earth.

“JAXA continues to investigate the relationship between the information from JSpOC and the communication anomaly,” the update stated.

JAXA has been observing the reported objects from two locations on southwestern Honshu Island. Radar at the Kamisaibara Space Guard Center (KSGC) detected an object located in the orbital direction of the short signal received at the Santiago Tracking Station. Telescopes at the Japan Space Forum’s Bisei Space Guard Center (BSGC) detected two objects around Hitomi’s original orbit.

A press release issued by JAXA on March 27 traced X-ray Satellite Hitomi’s current communication anomaly back to a failed communication operation that was scheduled for Saturday, March 26, at 16:40.

“Up to now, JAXA has not been able to figure out the state of health of the satellite,” the press release stated.

Paul D. Maley, an astronomer and space debris observer, observed Hitomi’s troubled acrobatics from his home base in the south central Arizona town of Carefree. He reported his observations in the Hitomi message thread on the Satellite Observations website at 3:36:24 Coordinated Universal Time.

“At 0319UT March 28 I observed Hitomi go through about 5 major rotation cycles and tracked/recorded it on video. Major peaks were at approximately 10 second intervals with minor peaks at 5 second intervals. 36 deg above the SSE, range approximately 1100km. Maximum magnitude reached +3. Other brightenings seen in between maxima. No other objects spotted in the immediate vicinity,” Maley noted.

Maley, a retired United Space Alliance project leader, described the science behind Hitomi’s wild tumbling and variable brightness in science journalist Nadia Drake’s National Geographic blog posting March 28.

“If the satellite were not tumbling, it would appear to be the same brightness. The fact that it is rotating with extreme variations in brightness indicates that it is not controlled and that some event caused it to begin its rotation,” Maley explained.

At the time of its communication anomaly, X-ray Satellite Hitomi was undergoing verification of onboard instrumentation functioning. A press release issued Leap Year Day, Monday, Feb. 29, by the Japan Aerospace Exploration Agency JAXA indicated a timeline of about one and one-half months for initial functional verification, followed by one and one-half months of calibration observations.

Hitomi smoothly detached from its launch vehicle, the H-IIA F30 (Flight number 30) rocket, about 14 minutes after liftoff at 5:45 p.m. Japan Standard Time, Wednesday, Feb. 17, from Japan’s Tanegashima Space Center.Japan Aerospace Exploration Agency Japan Aerospace Exploration Agency JAXA announced Hitomi’s successful completion of its critical operation phase via the agency's Feb. 29 press release. The critical operation phase refers to the period from detachment of launch vehicle to establishment of operational stability.

“The Japan Aerospace Exploration Agency (JAXA) confirmed the completion of a sequence of important operations of the X-ray Astronomy Satellite ‘Hitomi’ (ASTRO-H), including turning the cooling system on, test operation of the Soft X-ray Spectrometer (SXS), and extending the Extensible Optical Bench (EOB). With this confirmation, the critical operation phase of Hitomi was completed.

“Hitomi is now in a stable condition,” explained the press release.

The press release noted that the Soft X-ray Spectrometer’s cooling system was activated after Hitomi’s successful launch. The cooling system’s successful reach of the absolute temperature of 50 millidegrees (minus 273.1 degrees Celsius; minus 459.58 degrees Fahrenheit) was achieved around Monday, Feb. 22.

Prior to its successful launch into low-Earth orbit (LEO), Hitomi was known as ASTRO-H. The Japan Aerospace Exploration Agency JAXA only names successfully-launched satellites. Hitomi means “pupil of the eye.” The selected name symbolizes the x-ray satellite’s mission of scrutinizing space for answers to deep questions about the universe’s evolution and structure.

JAXA’s March 29 update expressed the agency’s determination to establish contact with its valuable satellite. Excluding instruments supplied by the Canadian Space Agency, the European Space Agency and NASA, X-ray Satellite Hitomi’s cost to the Japanese government reached 31 billion yen ($273 million; €191 million).

The update closed with the statement that “JAXA will do its best to recover communications with Hitomi and investigate the cause of the anomaly.”

Satellite Tracker, created by software developer Ciprian Sufitchi, is powered by N2YO: SPACE.com @SPACEdotcom via Twitter March 29, 2016

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

artist’s depiction of ASTRO H X-ray Observatory: http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=12120

Satellite Tracker, created by software developer Ciprian Sufitchi, is powered by N2YO: SPACE.com @SPACEdotcom via Twitter March 29, 2016, @ https://twitter.com/SPACEdotcom/status/714950344459948032

For further information:

Clark, Stephen. “U.S. military rules out collision as cause of Hitomi satellite’s woes.” Astronomy Now. March 30, 2016.
Available @ https://astronomynow.com/2016/03/30/u-s-military-rules-out-collision-as-cause-of-hitomi-satellites-woes/

“Current Status of Communication Anomaly of X-ray Astronomy Satellite ‘Hitomi’ (ASTRO-H)(Mar. 29).” JAXA > Topics > X-ray Astronomy Satellite ‘Hitomi’ (ASTRO-H). March 29, 2016.
Available @ http://global.jaxa.jp/projects/sat/astro_h/topics.html#topics7268

Drake, Nadia. “Video Shows Troubled Japanese Spacecraft Tumbling in Orbit.” National Geographic Blog: No Place Like Home. March 28, 2016.
Available @ http://phenomena.nationalgeographic.com/2016/03/28/video-shows-troubled-japanese-spacecraft-tumbling-in-orbit/

Nadia Drake‏ @nadiamdrake. "New video shows #Hitomi tumbling through space...doesn't look good. #AstroH." Twitter. March 28, 2016.
Available @ https://twitter.com/nadiamdrake/status/714578226073370624

Marriner, Derdriu. "Canadian ASTRO H Metrology System Nixes X-ray Telescope Camera Shake." Earth and Space News. Thursday, Feb. 11, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/02/canadian-astro-h-metrology-system-nixes.html

SPACE.com @SPACEdotcom. “Satellite Tracker and Interactive Map: How to Spot the Hitomi Satellite, Space Station & More.” Twitter. March 29, 2016.
Availabe @ https://twitter.com/SPACEdotcom/status/714950344459948032

SPACE.com Staff. “Satellite Tracker and Interactive Map: How to Spot the Hitomi Satellite, Space Station & More.” SPACE.com. March 29, 2016.
Available @ http://www.space.com/32054-satellite-tracker.html