News Debris event anomaly with Japan’s Hitomi space observatory

[boogabooga]

http://spaceflight101.com/fate-of-japanese-space-observatory-unclear-after-serious-on-board-anomaly/

 

[MaverickSawyer]

Well, that just sucks. Hope it's able to be salvaged...

 

[Andy44]

It's at a fairly high altitude, too, which means the junk will stay there for some time.

 

[Thunder Chicken]

Whatever it was, Hitomi now appears to be in a slow tumble.

Not looking good for recovery.

 

[GLS]

I was going to make the joke that we could send a shuttle up, but after seeing that video the joke won't work.

 

[Andy44]

Is that video in realtime? If so that tumble rate seems pretty excessive.

 

[Thunder Chicken]

Looks like Hitomi is still alive, after a fashion.

http://www.space.com/32408-japan-hitomi-satellite-tumbling-video-rescue-efforts.html

Doesn't sound too promising, but there might be a slim chance of getting communications in a patchwork fashion.

 

[Andy44]

So the vehicle is probably broadcasting via an omnidirectional antenna that has a partial sphere field of view, and as it tumbles the signal probably fades in and out. With no attitude control the solar panels may not gather enough energy to keep the batteries charged. There are probably heaters needed to maintain the payload and other equipment that need to be powered as well.

Best of luck to them, it seems pretty dire. At least Apollo 13 had a crew to get attitude control using a joystick. No such luck here.

 

[Notebook]

http://www.bbc.co.uk/news/science-environment-35929377

Scientists and engineers in Japan are scrambling to save a satellite and more than a quarter of a billion dollars of investment tumbling out of control in space.

http://www.bbc.co.uk/news/world-asia-35914652
N.

 

[Notebook]

Hitomi: Japan to abandon costly satellite sent to study black holes

http://www.bbc.co.uk/news/world-asia-36167064

Japan's space agency had said it will abandon efforts to restore or retrieve the ASTRO-H satellite.

Also called Hitomi, the satellite was launched in 17 February to observe X-rays coming from black holes.

 

[boogabooga]

Appears to have been a software glitch:

http://www.manufacturing.net/news/2016/05/mystery-hitomi-satellite-finally-solved

 

[ADSWNJ]

Relevant presentation: http://global.jaxa.jp/projects/sat/astro_h/files/topics_20160415.pdf

That's a hell of an expensive bug

 

[Andy44]

Wow, so it spun itself until it flew apart?! Interesting.

 

[ADSWNJ]

Crazy, right? You can bet that the next control SW will have more limit-checks to avoid that problem. (And sat manufacturer execs all over the world are probably typing emails to their QA teams to ask what check they have to stop their sats from doing the same thing!)

 

[Urwumpe]

How much G-force is that with just 21°/hour rotation? :blink:

---------- Post added at 08:49 AM ---------- Previous post was at 08:09 AM ----------

Ah, now I understand it - it was 21°/h at the last received telemetry and then the wrong RCS parameters accelerated the rotation rate rapidly, when the spacecraft entered safe mode

 

[Col_Klonk]

...when the spacecraft entered safe mode

Sounds like windoze..

Like some network 'engineers'.. I wonder why they don't have a terrestrial duplicate control system to do a test run first - only makes sense

 

[Urwumpe]

Sounds like windoze..

Like some network 'engineers'.. I wonder why they don't have a terrestrial duplicate control system to do a test run first - only makes sense

Hard to tell by the available data. A test article on the ground would not have caught any problem, by my understanding, since they are rather related to the physics in space. A simulation of the new RCS parameters should have found the bug, but I suspect, the simulation had been written by the same people who developed the RCS flight software (And thus contained the same wrong assumptions as the RCS software patch).

 

[Notebook]

http://www.bbc.co.uk/news/world-asia-36732336

A doomed Japanese satellite managed to capture a view of a galaxy cluster 250 million light years away just before it died, scientists have revealed.

Launched in February, the Hitomi X-ray satellite began tumbling out of control in March when contact was finally lost.

Just before its demise, scientists managed to extract data measuring X-ray activity in the Perseus galaxy cluster.

 

[mahdavi3d]

spacenews.com : NASA may build replacement instrument for Japanese astronomy mission

JAXA leadership is now talking about building a copy of Hitomi that could launch around the end of the decade. “JAXA has announced their intent to study a rebuild of Hitomi,” Hertz said, referring to that new spacecraft as ASTRO-H2. NASA, he said, is now studying developing a “build-to-print” version of the SXS for that new spacecraft.

JAXA has not formally agreed to develop ASTRO-H2, but the agency is seeking government approval as soon as possible. “They’re asking for permission to reprogram money in their current fiscal year budget. They want to get started this calendar year,” Hertz said, which would allow for a launch around 2020.