IPB

Welcome Guest ( Log In | Register )

Nozomi in perspective, Revisiting the causes of failure
pandaneko
post Oct 23 2011, 09:12 AM
Post #1


Member
***

Group: Members
Posts: 817
Joined: 17-April 10
From: Kamakura, Japan
Member No.: 5323



http://www.mext.go.jp/b_menu/shingi/uchuu/...ts/04061101.pdf

Above pdf file will be translated for aspiring students in aeronautics, control engineering etc. so that in future lay people like me will be able to enjoy planetary scenes and events without worrying about failures.

The overall title is "Looking into the causes of failure and trying to find the right measures to take for the future with respect to the 18th scientific satellite (PLANET-B ) not inserted into Mars orbit as planned" and it is dated 21 May 2004.

This file is very much detailed at 1.1 megabytes and the number of pages is about 40, I think. In addition, I will be translating 3 more files after this particular file. They will be;

1. ISAS file with views and comments on the failure
2. Another ISAS file, a newsletter written out in a series of 4 individual letters.
3. JAXA file, which is a press release and it is a very concise document with just sufficient details.

Re concise link making I tried a few times, but I simply failed and all the links will be fully pasted out as required.

Pandaneko
Go to the top of the page
 
+Quote Post
 
Start new topic
Replies
pandaneko
post Nov 4 2011, 09:50 AM
Post #2


Member
***

Group: Members
Posts: 817
Joined: 17-April 10
From: Kamakura, Japan
Member No.: 5323



QUOTE (pandaneko @ Oct 23 2011, 06:12 PM) *


above for ease of reference

page 12

2) Building in of LV2

We had debated about whether we should carry LV2 on Nozmi and our conclusion was that we should do so from the viewpoint of preventing a massive reverse flow of oxidiser vapour. LV2 is placed in the propulsive system at the downstream side of the regulator after the forking out of fuel and oxidiser pipes and between the check valve CV2 and the oxidiser tank (schematic II-1-1). Its function is to prevent the mixing of fuel and oxidiser at the gas side of the system.

With this particular propulsive system we are employing a dual redundancy system of accident prevention together with the CV2 placed in the upstream. This dual redundant system with LV2 and CV2 does not mean we did not have confidence in any of these valves. Rather, it was employed to increase reliability to an even higher stage against the reverse flow of vapour which might lead to a fatal accident, damaging the probe.

During the development stage of Nozomi in 1994 an accident occurred to a US Mars probe (Mars Observer) and it was lost. Its cause was estimated to be an accidental mixing of oxidiser and fuel vapours in the gas system pipeline. Reverse vapour flow is likely to lead to a total loss of a satellite and this point was also taken into consideration.


3) Adding LVDT

About whether we should install a valve status monitor LVDT with the LV2 our conclusion was that LVDT constituted an important source of information for the steady operation of LV2, reducing the pressure on the operating team and the possibility of human errors.

In the case of Nozomi, on the other hand, there was a factor of influence at the time of valve selection arising from the merger and acquisition of the US valve manufacturer in that it meant the addition of LVDT to a valve without a status monitor but with an ample proven record of operation.

Generally speaking the reliability evaluation of a design change to an operationally proven part has not been established just as in the case of newly developped parts. However, our judgement was that this was going to be based on an operationally proven valve and the design change was going to be introduced by a reliablbe US manufacturer and consequently the risks involved in this design change were small enough. For this reason we selected the LV2 with LVDT added to it.

As shown in the table II-2-1 the risk of valve mulfunction after the desing change was thought to be similar to that of operationally proven valves.

end of page 12

P

表Ⅱ-2-1に示すように、バルブ開閉ができなくなるリスクでは、改造品といえども、そのリスクは搭載実績品と同様であると判断されていた。
Go to the top of the page
 
+Quote Post

Posts in this topic
- pandaneko   Nozomi in perspective   Oct 23 2011, 09:12 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 24 2011, 08:53 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 24 2011, 09:37 AM
- - Phil Stooke   Thanks for doing this. It is very interesting. P...   Oct 24 2011, 11:04 AM
- - nprev   Yes indeed, THANK you, Pandaneko! In my opinio...   Oct 25 2011, 01:51 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 25 2011, 08:58 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 26 2011, 09:26 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 27 2011, 09:09 AM
|- - PaulM   I understand that the reason for the final failure...   Oct 27 2011, 11:52 AM
- - Paolo   the reason why Spirit and Oppy survived the April ...   Oct 27 2011, 12:09 PM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 28 2011, 09:43 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 29 2011, 09:39 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 30 2011, 09:03 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Oct 31 2011, 09:38 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 1 2011, 09:19 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 2 2011, 09:22 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 3 2011, 09:36 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 4 2011, 09:50 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 5 2011, 09:30 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 6 2011, 09:03 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 9 2011, 09:23 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 10 2011, 09:51 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 11 2011, 09:09 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 12 2011, 09:38 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 13 2011, 09:04 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 13 2011, 09:14 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 14 2011, 09:04 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 15 2011, 09:07 AM
- - Paolo   thanks again for the translations, panda! I kn...   Nov 15 2011, 06:21 PM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 16 2011, 09:49 AM
|- - pandaneko   QUOTE (pandaneko @ Nov 16 2011, 06:49 PM)...   Nov 16 2011, 09:53 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 17 2011, 10:27 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 18 2011, 09:25 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 19 2011, 09:46 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 20 2011, 09:22 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 21 2011, 09:35 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 22 2011, 09:12 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 23 2011, 09:29 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 24 2011, 09:39 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 25 2011, 09:41 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 26 2011, 09:42 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 27 2011, 09:23 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 28 2011, 08:44 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 29 2011, 09:05 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Nov 30 2011, 09:04 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 2 2011, 09:26 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 3 2011, 10:00 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 4 2011, 09:06 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 5 2011, 09:51 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 6 2011, 12:09 PM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 7 2011, 08:42 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 8 2011, 09:41 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 9 2011, 10:08 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 11 2011, 09:57 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 12 2011, 09:51 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 13 2011, 10:08 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 14 2011, 09:15 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 15 2011, 09:46 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 16 2011, 01:00 PM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 17 2011, 09:42 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 18 2011, 09:29 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 19 2011, 09:29 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 20 2011, 11:43 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 21 2011, 11:27 AM
- - Paolo   thanks panda, I look forward to your translations ...   Dec 21 2011, 01:08 PM
|- - pandaneko   QUOTE (Paolo @ Dec 21 2011, 10:08 PM) tha...   Dec 21 2011, 01:44 PM
- - elakdawalla   I was thinking that a way to make good use of pand...   Dec 21 2011, 05:52 PM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 22 2011, 10:56 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 23 2011, 09:36 AM
- - Astro0   That's a great story about the 16-bit coding ...   Dec 23 2011, 09:42 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 24 2011, 10:19 AM
|- - pandaneko   What follows is the URL of the press release of JA...   Jan 17 2012, 10:11 AM
|- - pandaneko   What follows is the URL of the ISAS pages I am abo...   Jan 19 2012, 08:28 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 20 2012, 09:06 AM
||- - pandaneko   QUOTE (pandaneko @ Jan 20 2012, 06:06 PM)...   Jan 22 2012, 12:57 PM
||- - pandaneko   QUOTE (pandaneko @ Jan 22 2012, 09:57 PM)...   Jan 23 2012, 09:16 AM
||- - pandaneko   What follows is the chunck immediately following t...   Jan 24 2012, 10:07 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 25 2012, 09:47 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 26 2012, 09:33 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 27 2012, 08:44 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 27 2012, 09:52 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 28 2012, 08:27 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 28 2012, 08:58 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 29 2012, 09:53 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 30 2012, 09:09 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Jan 31 2012, 10:19 AM
||- - pandaneko   QUOTE (pandaneko @ Jan 31 2012, 07:19 PM)...   Feb 14 2012, 09:13 AM
||- - pandaneko   I was not exactly sure where I should place this p...   Mar 10 2012, 08:26 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Feb 1 2012, 09:59 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Feb 2 2012, 09:42 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Feb 3 2012, 09:44 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Feb 5 2012, 09:07 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 19 2012, 05:28 PM)...   Feb 6 2012, 09:54 AM
- - pandaneko   QUOTE (pandaneko @ Oct 23 2011, 06:12 PM)...   Dec 25 2011, 09:36 AM
|- - pandaneko   QUOTE (pandaneko @ Dec 25 2011, 06:36 PM)...   Dec 26 2011, 10:09 AM
|- - pandaneko   QUOTE (pandaneko @ Dec 26 2011, 07:09 PM)...   Jan 13 2012, 10:13 AM
|- - pandaneko   QUOTE (pandaneko @ Jan 13 2012, 07:13 PM)...   Jan 14 2012, 10:15 AM
- - Astro0   I think that all of UMSF owes you an enormous debt...   Feb 6 2012, 11:23 AM
- - Paolo   Pandaneko probably knows but maybe other group mem...   Feb 6 2012, 12:57 PM
- - pandaneko   QUOTE (Paolo @ Feb 6 2012, 09:57 PM) Pand...   Feb 6 2012, 01:59 PM


Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 31st October 2024 - 11:42 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.