Nozomi in perspective, Revisiting the causes of failure Options

[pandaneko]

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

[pandaneko]

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

above for ease of reference

page 28


(2) Measures taken in our satellite operation

Given Nozomi's launch window the timing of OME firing for transfer orbital insertion (TMI) had to be within the invisible time zone in our orbit plan design. We outline the measures taken in operating this satellite as follows.

In order to combat invisible operation during TMI we thought of requesting the support of NASA's Deep Space Network (DSN) or ESA so that they may allow the use of of their ground stations. However, our final decision was that we will not be requesting their support for the following reasons.


・Nozomi was equippred with automatic OME firing function.

・ This automatic OME firing function was also going to be used in Mars orbital insertion and a thorough ground verification had been made.

・It had been planned so that an orbital firing test of this automatic function was going to be made during visible operational period (in fact, this automatic OME firing was tested about 4 months before TMI during ΔV5).

・ Nozomi's TMI timing coincided with the period in which Nozomi was also invisible to DSN and ESA ground stations.

However, we cannot deny the fact that had we been able to send an immdeiate response command to the event that happend in real time monitoring in visible operation through telemetry we may have been able to carry out the originally planned task. This does suggest that securing operational visibility is very important. One such measure that can be taken in this respect is to request the support of overseas ground stations. We can think of a few things as follows for achieving this.


・ Make preparations through international cooperation so that quick response commands can be sent out by DSN and ESA ground stations.


・We establish our own overseas ground stations (for example, one such station in South America)

In the case of 20th scientific satellite (Hayabusa) launched in 2003, in this regard, we did request such support from DSN for emergency measures.


- 28 -

However, we must point out that even in the case of visible operation we still have this issue of time lag in deep space operation and that for this reason we will still have to rely on autonomous operation despite the risks inherent in this kind of satellite operation.

end of page 28

P