Author Topic: LIVE: H-IIA - Hitomi (ASTRO-H) - February 17, 2016 (08:45 UTC)  (Read 62915 times)

Offline yoichi

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http://global.jaxa.jp/projects/sat/astro_h/files/topics_20160524.pdf
Hitomi Experience Report: Investigation of Anomalies Affecting the X-ray Astronomy Satellite “Hitomi” (ASTRO-H)
May 24, 2016
JAXA

Offline gospacex

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I must respectfully disagree.  Asuka and Suzaku worked for 7 and 10 years respectively before they failed.  Akari operated successfully for 5 1/2 years.  Only Hitomi has been a total failure.

1 out of 7 ain't bad odds, given the Japanese dedication to holding costs down on their science missions.
Well maybe they should re-examine the idea of always holding down costs if it's going to cause major failures such as this. Better to spend a bit more money if it means avoiding this kind of loss.

It's easy to say post-factum.
Spending more and more money and adding layers and layers of testing can give you a very reliable system... which then ends up being too costly and noncompetitive. Ask ULA.

Finding a good balance between reliability and cost is nowhere near easy.

Offline Sam Ho

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http://global.jaxa.jp/projects/sat/astro_h/files/topics_20160524.pdf
Hitomi Experience Report: Investigation of Anomalies Affecting the X-ray Astronomy Satellite “Hitomi” (ASTRO-H)
May 24, 2016
JAXA
That's quite a mishap report.  As with most mishaps, there's a chain of events leading up to the loss of spacecraft.

1. February 28, 2016: Operator fails to remove minus signs in copying data from one tool to another.  Verification of the dataset is missed twice.  Root cause is lack of documentation.  Result is that Thruster Safe Hold mode is rendered unsafe and will instead spin spacecraft up until catastrophic structural failure occurs.  (Mechanism 3)

2. Design decision: Interaction of Star Tracker and Inertial Reference Unit logic in attitude control system.  Star tracker mode switch causes glitch in IRU bias estimate, which the Star tracker corrects over time, but if the Star tracker suffers a glitch as well, the IRU can end up far enough off that the AOCS rejects the Star tracker's correction when the Star tracker comes back on line.  This happens March 26.  (Mechanism 1)

3. Design decision: Reaction Wheel Safe Hold is triggered by Attitude Control System, not by Sun Sensors.  The failure above means that the AOCS has the wrong state, so it never triggers RW Safe Hold.  Reason for this decision is that Sun Sensor field of view is smaller than the off-pointing in normal operation.  (Mechanism 2)

4. Catastrophic structural failure.  Solar arrays break off.  (Mechanism 4)

Offline Star One

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I must respectfully disagree.  Asuka and Suzaku worked for 7 and 10 years respectively before they failed.  Akari operated successfully for 5 1/2 years.  Only Hitomi has been a total failure.

1 out of 7 ain't bad odds, given the Japanese dedication to holding costs down on their science missions.
Well maybe they should re-examine the idea of always holding down costs if it's going to cause major failures such as this. Better to spend a bit more money if it means avoiding this kind of loss.

It's easy to say post-factum.
Spending more and more money and adding layers and layers of testing can give you a very reliable system... which then ends up being too costly and noncompetitive. Ask ULA.

Finding a good balance between reliability and cost is nowhere near easy.

What is being competitive got to do with a mission like this so I don't see how the comparison to ULA is at all valid. This is a bespoke science mission not a launcher supplier.

Offline gospacex

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I must respectfully disagree.  Asuka and Suzaku worked for 7 and 10 years respectively before they failed.  Akari operated successfully for 5 1/2 years.  Only Hitomi has been a total failure.

1 out of 7 ain't bad odds, given the Japanese dedication to holding costs down on their science missions.
Well maybe they should re-examine the idea of always holding down costs if it's going to cause major failures such as this. Better to spend a bit more money if it means avoiding this kind of loss.

It's easy to say post-factum.
Spending more and more money and adding layers and layers of testing can give you a very reliable system... which then ends up being too costly and noncompetitive. Ask ULA.

Finding a good balance between reliability and cost is nowhere near easy.

What is being competitive got to do with a mission like this so I don't see how the comparison to ULA is at all valid. This is a bespoke science mission not a launcher supplier.

Science missions cost money too. You need to convince government to give you that money. The more you ask for, the lesser are chances the answer will be positive.

Therefore for science missions you still need to play the same balancing act between lowering costs and ensuring high reliability.

Offline Star One

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NASA and JAXA begin discussions on aftermath of Hitomi failure

http://spacenews.com/nasa-and-jaxa-begin-discussions-on-aftermath-of-hitomi-failure/

Certainly doesn't look there will be any full fledged like for like replacement mission anytime soon.

Offline jacqmans

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June 15, 2016 (JST)

JAXA Executives Take Pay Cut Due to ASTRO-H (Hitomi) Anomaly

Due to the anomaly experienced with X-Ray Astronomy Satellite ASTRO-H (Hitomi), three of the Japan Aerospace Exploration Agency's executive employees have decided to take a 10% pay cut to their monthly salary for four months, to be effective July 2016.

The affected employees are as follows:
President: Naoki Okumura
Senior Vice President: Mamoru Endo
Vice President/Director General, Institute of Space and Astronautical Science: Saku Tsuneta


URL:
http://global.jaxa.jp/press/2016/06/20160615_hitomi.html


National Research and Development Agency Japan Aerospace Exploration Agency (JAXA)

Offline Scylla

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The final image sent by doomed Japanese Hitomi satellite
http://www.bbc.com/news/world-asia-36732336

Image of the Perseus cluster taken by Nasa's Chandra X-ray satellite, overlaid with data taken by Hitomi, outlined by an orange box, showing X-rays emitted by iron and nickel in hot gas between the galaxies
I reject your reality and substitute my own--Doctor Who

Offline Star One

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Offline yoichi

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http://www.jaxa.jp/press/2016/07/20160714_hitomi_j.html
For consideration of the successor to the X-ray astronomy satellite ASTRO-H

http://www.jaxa.jp/press/2016/07/files/20160714_hitomi_01_j.pdf
(1.1MB/Japanese)

Offline as58

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So it looks like a reflight in 2020. Hitomi is really following in Suzaku's footsteps

Offline Star One

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LIVE: H-IIA - Hitomi (ASTRO-H) - February 17, 2016 (08:45 UTC)
« Reply #231 on: 07/20/2016 08:26 PM »
Jeff Foust –  ‏@jeff_foust

Hertz: JAXA is asking permission to reprogram funding in its current fiscal year to start ASTRO-H2 this calendar year; launch 2020.

NASA’s Paul Hertz: NASA doesn’t want to get into a partnership unless we’re confident it will result in a successful mission.

Back at the astrophysics subcommittee meeting, some members seem concerned about working with JAXA because of Hitomi and previous failures

« Last Edit: 07/20/2016 08:27 PM by Star One »

Offline Star One

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Offline Star One

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LIVE: H-IIA - Hitomi (ASTRO-H) - February 17, 2016 (08:45 UTC)
« Reply #233 on: 09/22/2016 07:33 PM »
Quote
Jeff Foust –  ‏@jeff_foust

Okumura: expect Diet to approve budget bill, and thus decide on funding for ASTRO-H replacement, by the end of December.

https://mobile.twitter.com/jeff_foust/status/779004111886876673
« Last Edit: 09/22/2016 07:33 PM by Star One »

Offline Sam Ho

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Quote
Jeff Foust –  ‏@jeff_foust

Okumura: expect Diet to approve budget bill, and thus decide on funding for ASTRO-H replacement, by the end of December.

https://mobile.twitter.com/jeff_foust/status/779004111886876673
Jeff Foust's article on the above:

http://spacenews.com/japan-to-decide-on-hitomi-replacement-by-years-end/

Offline zubenelgenubi

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Cross-posting from X-Ray Astronomy Recovery Mission (XARM) thread:

Some good news as this mission will replace the recently lost Hitomi.

Quote
WASHINGTON — NASA and the Japanese space agency JAXA will start work this spring on an orbiting X-ray astronomy telescope to replace one lost shortly after launch last year.

In a presentation to the Committee on Astronomy and Astrophysics of the National Academies March 28, Paul Hertz, director of NASA’s astrophysics division, said a formal start of the project known as the X-Ray Astronomy Recovery Mission (XARM) will take place shortly after the start of the new Japanese fiscal year April 1.

“We are moving forward with the X-Ray Astronomy Recovery Mission,” Hertz said. The mission, he said, was included in the Japanese government’s budget for the new fiscal year, pending approval by the country’s parliament, the Diet.

- See more at: http://spacenews.com/nasa-and-jaxa-to-develop-replacement-x-ray-astronomy-telescope/#sthash.tVHs7M9C.dpuf
« Last Edit: 06/14/2017 12:52 AM by zubenelgenubi »
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