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Nozomi in perspective, Revisiting the causes of failure
pandaneko
post Jan 17 2012, 10:11 AM
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What follows is the URL of the press release of JAXA on Nozomi's failure.

http://www.jaxa.jp/press/2003/12/20031210_nozomi_j.html

About this coding business I have been thinking about it for the last three weeks. Simplest would be to experiment. Here, I will switch on my hardware switch to write "1 A" using 16 bits coding. What goes before that is "1 A" with 8 bits coding.

1. 1 A with 8 bits coding: 1 A

2. 1 A with 16 bits coding: 1 A

With 2. above, I actually added one space with 16 bits coding and that may complicate this issue, but not by much, I hope...

If you can read them both without any problems, then I can forget about my worries about this, except that there might still be cases where the person(s) who wrote the whole thing may have used the mixture of 8 and 16 bits codings without consistency.

This is not a small matter of concern. On placing mail orders, for example, your order may be rejected. It does happen, here, often...

Pandanakeo
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pandaneko
post Jan 19 2012, 08:28 AM
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What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".

This is entirely in accordance with the purpose of my translating relevant files for the advancment of future missions and I am very pleased that I found this particular file for the communities with interest.

Translations will follow shortly. The original file consists of 4 contributions made by the same person and each may take up to a few times of translation. I will not be identifying the name of the person who wrote these pages.

P
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pandaneko
post Jan 20 2012, 09:06 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".

This is entirely in accordance with the purpose of my translating relevant files for the advancment of future missions and I am very pleased that I found this particular file for the communities with interest.

Translations will follow shortly. The original file consists of 4 contributions made by the same person and each may take up to a few times of translation. I will not be identifying the name of the person who wrote these pages.

P


In what follows I am translating this document chunk by chunk as I see fit for the purpose because there are no page numbers as such.

Nozomi left the Earth on 4 July 1998 and travelled across the solar system for over 5 years carrying signatures of hope from more than 270,000 people. I regret to say that we had to teminate the operation of Nozomi at 20:30 on 9 December 2003 (Tuesday) despite the frantic efforts by the team upon confirmation that we had not been able to fix the faulty portions of the system.

Consequently, we kept sending out a command to Nozomi from 20:45 until 21:23 on the same day in order to reduce the possibility of Nozomi colliding with Mars. As a result, Nozomi passed, on 14 December, the height of about 1000 km from the surface of Mars and left the gravitational field of Mars to continue its journey across the solar system once again.

Nozomi, the first of its kind ever launched by Japan, has encountered all kinds of difficulties over the last 5 years as had been expected, had to terminate her mission within the last few steps from her success.

Granted that Nozomi, as Japan's first planetary mission, was not able to achieve the maturity as is now taken for granted in other areas such as X-ray astronomy and space plasma physics we nevertheless think that the lessons learnt from operating this spacecraft in the frenzies of it all during the last 5 years must be told to the rest of the world so that our future planetary missions will benefit from the difficulties Nozomi encountered.

I believe that it is the duty of our group to do just that. We were endowed with the resources for that purpose. We must reflect upon failures. That is the only way foward. Both US and Soviet Union have sent more than 30 spacecrafts to Mars to date and 20 of them have failed. (Is this really, really true?, I doubt it, P) We will have to learn from failures. That is the only way forward.

Learn from successes, ride over the faults we found, it is not regrets, not masochistic either, at all, and we can only do forward looking investigations for the humanity.

P
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pandaneko
post Jan 22 2012, 12:57 PM
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QUOTE (pandaneko @ Jan 20 2012, 06:06 PM) *
Learn from successes, ride over the faults we found, it is not regrets, not masochistic either, at all, and we can only do forward looking investigations for the humanity.


One chunck after above just before two graphs is as follows.

1.On the subject of engineering aspects

There are 4 Japanese spacecrafts which have left the Earth gravitational fields. The first one is the Halley probes, Sakigake and Suisei launched in 1985, then Nozomi, and Hayabusa which is the latest departing in May 2003. However, of all these, Nozomi is the only one which specifically targetted a planet as its destination.

Given limited human resources and finance, very tight scheduling it has been a very challenging task to try and reach a planet. It has been fun, too, of course, with all those technologies to prove in orbit.

First of all, we had this mission analysis. We have gained quite a lot from trying to trade off an innumerable number of engineering aspects in an effort to obtain the maximum benefit from an optimum flight scenario for Nozomi.

I think we have secured the solid foundation for orbital desine and operation technologies, in addition to the experience gained during the flight of Hiten which was launched in 1990, making use of swing-bys with the Earth and the Moon.

Needless to say that we were all very much encouraged and impressed by the frantic efforts shown by this "Orbit and Mission" team, sacrifysing the period non-stop, from Christmass through to the new year period in the face of fuel depletion in the wake of the Earth swing-by in 1998. The heroic dedication that they showed in coming up with a renewed mission plan was a ray of hope for the Japanese space science and technologies.

End of this chunck and this is followed by schematics. I am unsure as to what I might do about them, yet. P

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pandaneko
post Jan 23 2012, 09:16 AM
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QUOTE (pandaneko @ Jan 22 2012, 09:57 PM) *
End of this chunck and this is followed by schematics. I am unsure as to what I might do about them, yet. P


With these two schematics my contributions are minimum and it shouod suffice. The first one on the left is all in English. The second one on the right is more or less self-explanatory. I might add that red is Mars, purple is Nozomi and the green is the Earth. What follows after these graphs is as follows.

Next is the technology for determining the orbit very accurately. We have obtained these technologies and trained ourselves in them from the interactions between the ground based commands and the responses from the spacecraft so tha we now know how we can determine orbits in deep space, line of sight distance, velocity data etc. to put them into an extremely precise dynamical model

Also, autonomous technology. Sometimes, it takes as much as 20 minutes by the radio waves to reach the spacecraft. Therefore, a lot of decisions are left for the spacecraft to make by the onborad computers. We managed to gain a limited amount of insight into the workings of "autonomous decision makings". This experience was put into a maximum use in the case of Hayabusa.

In short, we have obtained a maximum experience from our attempts with perational know-hows and use of relevant communication means to keep communications alive over the distance of more than 3.7 times 10 to the power of 8 km using our 64m diameter dish at Usuda station in central highland area of Japan.

end of this particular chunck. P

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pandaneko
post Jan 24 2012, 10:07 AM
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What follows is the chunck immediately following the reference to the deep space antenna located in the high land area in central Japan where my family's mountain cottage happens to be only 10 miles from it!

We have also gained a lot in our attemtps to reduce inertial mass of instruments on board. Planetary exploeres need a lot more energy at launch compared with earth circulating satellites. Electronics, cells, antenna, solar batteries, propulsion systems, all these called for new technologies for reduced mass. We believe that we cleared all these hurdles with Nozomi.


(There is a schematic of Nozomi after this, but it should not be a concern to our colleagues. So, I will skip translation here.)


We had not expected to be involved in such a lengthy operation, including a long cruising phase. Under these circumstances, we had to operate very safely given all kinds of constraints and that meant that a lot of the ground support software had to be turned into AI capable, and that brought to us lots and lots of precious experiences.

All this gave us quite a lot for the operation of Hayabusa and all other future planetary missions. On the other hand, there is one notable point of regret in relation to the valve we had incorporated into the control engine in the wake of the US Mars Observer's bitter experience.

What started Nozomi's agony was the half opening of the shut valve which had been put in the downstream of the reverse flow stop valve in the gas supply line which was meant to pressurise the fuel and oxidiser tanks. Other people's experiences are hard to digest.

We did mean to have learnt from the US experience and we might have installed unneccesary redundancies into our system, or did we? In any event, we will need to spend a lot of time looking into the operational aspects of this and all other relevant pitfalls we might have fallen into.

We also have this short-circuitting issue, following the direct hit by solar particles. There have been many failures to date due to these large scale solar flares. We believe that recent explosions crippled at least a dozen spacecrafts worldwide. We cannot afford to say that ours had been up to the international standard for this kind of troubles. We will have to come up with solutions once and forever.

There are two points here, which we need to examine very carefully.

One is that our original design had been such that a command sent to the short-circuitted portion will automatically bring about an exccessive current, activating a circuit breaker, leading to an immediate loss of the current. However, if you come to think about it this particular breaker had been installed there in the first place to protect the whole circuit. We had the reverse effect of this precaution.

Sure, it may be impossible to take everything into account. However, this reverse effect issue, be it with the valves, or breakers, does and will continue to happen, I think. Many other missions of this kind worldwide have seen this "reverse effects" cropping up almost constantly.

It may well be that there are more than one way of making the maximum use of this experience with the breaker. I can say, at least, that we are that much cleverer now as a result.

Second point of possible arguements is this. This particular circuit had been meant to control both telemetry modulation and the heater for control fuel. Granted that this was due to the utmost need to reduce inertial mass. However, if one of the two had been alive for use we might have found a way to come up with a solution. I am sure that this will be one of the focuses of arguments from now on.


As the first of our planetary missions Nozomi left a lot of issues for us to ponder over and come up with viable solutions for. I am sure that we will be willing to spend time on these issues for many years to come.

end of this chunck. P
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pandaneko
post Jan 25 2012, 09:47 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


What follows is the start of the part 2 of this 4 article series. This is immediately followed by the Lyman aplha schematic.


2.About science observations

Nozomi had in total 15 different means of observing the Mars. Following the trouble with the Earth swing-by in 1998 and the period following it for 5 years in wait mode with Sun-centric orbits we made a lot of scientific observations, mostly to check up on the health of the instruments on board, and some of these included very unique observations.

Mars camera (MIC) sent us a two-shot view of the Earth and the Moon in July 1998. This particular photograph did not have any value to professionals and exterts at all, but once it was carried on newspapers it brought in a lot of emotional responses from the general public. It is a kind of " memorial snap shot" of friendly planets, all travelling in the vast expanse of the universe.

Also, Nozomi became the first space probe sent by Japan to have a look at the other side of the Moon for the very first time in history.

Nozomi's ultraviolet spectrographic camera made measurements on the hydrogen Lyman alpha line in the interplanetary space. Hydrogen Lyman alpha radiation from the Sun is scattered by the neutral hydrogen atoms floating in the interplanetary space and lights up the space.

It reminds us of the fact that the air-molecules surrounding the Earth scatter the solar ray, producing the beautiful blue sky for us. Where do all these hydrogen atoms come from? They originate in the material flow called "interplanetary wind" in our galactic system.

This interplanetary wind, as it approaches the Sun, is ionised by the energy of the solar wind and the ultraviolot component of the Sun's radiation. Thes ionised hydrogen atoms will no longer scatter hydrogen Lyman alpha light and the less condensed, by ionisation, interplanetary wind will continue its travel downstream.

It is for this reason that the Lyman alpha light looks stronger in the direction from which it is coming and darker in the opposite direction. From the observation made by Nozomi of the hydrogen Lyman alpha light distribution and its intensity in the interplanetary space we are trying to study the properties of the Solar wind causing all these changes.

End of this particular chunk. P
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pandaneko
post Jan 26 2012, 09:33 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


The previous posting is followed by a schematic called " Internplanetary hydrogen alpha light intensity distribution" (please refer to this with above URL) and what follows comes right after this schematic.

Charged particles are constantly trying to flow out from Earth ionosphere. These particles, however, are trapped by the Earth's magnetic field and unless there are huge disturbances in this magnetic field they cannot hope to escape into space. It has been thought that these "cold (not energetic enough) charged particles are trapped by the magnetic lines which on average pass at the height of about 4 times of the radius of the Earth in the equiatorial plane.

90 % of these trapped particles are hydrogen ions and the rest are mostly helium ions. It is these helium ions which refelect the ultra viloet lgiht radiated the Sun.

Nozomi's XUV, the Extreme Ultra Violet telescope, had the first glimpse of this region for the first time from outside. Nozomi's obervation showed that a lot more than imagined amount of helium ions are leaving from this region into outside space.

(There is an image right after this, which can be enlarged on clicking)

Nozomi's MDC, the dust counter, started its measurement soon after launch in July 1998 and continued its operation for nearly 4 years until April 2002, looking at the space surrounding the Earth and also interplanetary dust velocities and masses.

Nozomi recorded about 100 clear dust collisions over the 4 year period starting with the first identification of a constellation (I may be wrong with this translation, P) on 11 July 1998. Most of these dusts measured by Nozomi's MDC are thought to be originating from asteroids and commets in their Kepler circulation orbit, but some are thought to be clearly originating from outside the Solar system.

In 1999 Nozomi measured at least 4 extra galactic high velocity dusts. Of these, 2 of them had their velocity vectors coinciding with those of the velocities and ditrections with which the Solar system moves relative to surrounding interplanetary gasses. It is therefore thought that these are dusts coming from the interplanetary region.

The fact that these extra solar system dusts were ever measued within the Earth region is one important contribution to our knowledge.

(end of this chunck, P)
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pandaneko
post Jan 27 2012, 08:44 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


What follows is the start of the part 3 of this part 4 series of newsletter by ISAS. I am first translating the captions contained in the very first schematic titled "Electron Spectrum Analyzer/Nozomi". They are as follows.

"Electron velocity direction in the ecliptic frame of reference" is directly on the schematic. Within the schematic itself, the caption around the dot in red says "Solar wind electtrons" and the one on the right to it says "Electrons from the Moon".

Red dot means the direction of the sun and the asterisk looking-like symbol is the magnetic lines. Disk like thing is the shadow cast by the Moon and its tail.

Now, what the chunk at the start says:

"Now, it seems I cannot paste what I copied. Instead of loosing above translation I will let this go first and upload the translated chunk seperately, P"

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pandaneko
post Jan 27 2012, 09:52 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


Nozomi made observations during the time of the Moon swing-by. This was in order to look into the plasma environment surrounding the Moon.

Our Moon absorbs the solar wind which is a flow of plasma from the Sun. However, Nozomi's ISA, Ion particles (maybe, spectrum, P) analyser, detected, for the first time, the plasma which was part of the Solar wind that had been reflected by the front face of the Moon.

We examined ion velocities, Moon position, direction of the Solar wind etc in great details and as a result we found that this particular plasma was closely related to the Moon and that it had not been newly formed by the Moon and that it had rather been formed by the reflection of the Solar wind by the Moon.

It has been often said, as a result of Apollo landers, that some parts of the Lunar rocks are weakly magnetic and this seems to confirm that the shock waves formed by the Solar wind on colliding with these magnetised rocks are reflecting the Solar wind ions.

This would mean that the Solar wind is blocked at the front face of the Moon, leaving a vacuum region at the back with an extremely less plasma density. Nozomi's onboard ESA detected these electrons coming from this vacuum region.

It had been predicted that there was to be a potential difference of a few tens of Volts through the mechanism called "bipolar dispersion (best I could translate, P) between the vacuum region and the Solar wind. However, given that the reflected electrons had something like 480 eV, very high indeed, 10 times the predicted value and We may have to accept that.

(end of this chunk, P)
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pandaneko
post Jan 28 2012, 08:27 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


The posting just befroe this was referring to a schematic called "Electron Spectrum Alalyser/Nozomi" and that is immediately followed by another schematic, actually a chart, and there are two captions on this chart. Chracter strings in white say "Ions reflected by the front face of the Moon" and those in red say "Solar wind ions".

Here below is today's translation immediately following this chart.

I seem to have failed yet again. I cannot paste what I copied. Maybe, I shoud not have copied schematics at the same time? So, I let this go as it stands. P



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pandaneko
post Jan 28 2012, 08:58 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


EIS, the high energy particle counter(?), played its role as a monitor of the Solar wind at positions further away from the Earth and made contributions to the obervation of the Solar flares. In April 2002, it detected a Solar surface explosion which must have caused its own suffering from it.

(There is a chart immediately following this short text and the caption on it says "Maximum number of particles ever measued by Nozomi on 21 April 2002")

Magnetic field measurement device on board Nozomi made observations on the magnetic field emitted by the Sun during its cruise phase. The Solar wind, which is a supersonic plasma wind blowing out of the Sun's surface, carries Sun's surface magnetic field with it into the interplanetary space.

It is not terribly exciting simply to be able to measure these magnetic fields. However, Nozomi's observations were made much further away from the Earth in orbit and in that respect the data obtained was very much precious.

Nozomi made these observations as it was moving further and further away from the Earth and consequently it became possible to study how the magnetic fields of the Solar wind behaves as they move further away from the Sun.

Also, it is not easily generally possible to know the velocity (or speed) of the Solar wind in the vicinity of the Sun. However, we can measure its lateral velocity when a specially dense Corona material gashes out at right angles to the line of sight as seen from the earth.

Nozomi made direct observations of these Corona related materials and consequently we were able to obtain very precious information on how an initial velocity of the Solar wind gradually changes in the interplanetary space. (This might be useful for weather forecast for ISS?, P)



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pandaneko
post Jan 29 2012, 09:53 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


Immediately after the paragraph I translated yesterday is a small schematic, depicting te relative position of the probe against the plobe coming out from the Sun. The caption there says "Please refer to the floowing URL for details of the co from the Sun and Nozomi waiting to observe it". (I am not translating this)

(Now, in what follows, a schematic of "Solar corona observation by phase shaking (?) detection" and this in blue.)

(On the schematic itself there are 3 character sets as follows)

1. Frequency changes (f down= 11/3X f up)

2. transmission wave , S band (2.3 GHz)

3. Reception wave, X band (8.4 GHz)

(There are 2 rectangular blocks underneath these S and X bands and they are: )

(S band transmission) generated by a highly stable (10 to the power of minus 15) hydrogen maser

(X band transmission) reflecting the changes in the refractive index over the outgoing and incoming (inbound) routes

The antenna at the bottom is the Usuda antenna.

Next, immediately following all above is a chart called "Phase change (?) spectrum". The vertical axis is "Phase change power (rad 2/ Hz)" and the horizontal is "frequency change (Hz)". There are 4 character sets on this chart, going clockwise and they are:

1. 12 to 37 Solar radii until the Solar surface (6 to 28 December 2000)

2. Kormograph side (unsure about this translation, must be somebody's name)

3. when very far from the Sun (June 2000)

4. comparative correction signal

Just underneath all these and in pale blue is "space scale (300km/s assumed)"

Perhaps, end of part 3 of this part 4 series, P



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pandaneko
post Jan 30 2012, 09:09 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


What follows is a short paragraph immediately after the Phase change spectrum and immediately before the start of part 3 of this part 4 series.

As I think of all those people all over the world who had sacrificed their lives and designed instruments on board which were never used despite being so close to the Mars I feel so frustrated and sad to the extent of feeling like crying.

Nozomi had a formidable assembly of first rate magnetic and plasma observation means on board. Nozomi was to have played a significant auxilliary role side by side with European and US observers currently going there. My heart is bleeding for my colleagues.

Towards the end of the operationn there came in a flood of mails and telephone calls from all over the world, all encouraging us for then and the future. Here, I only simply aplogize for the fact that we were not able to comply with their aspirations.

Needless to say that our Nozomi team will never ever forget the fervent encouragement given to us by our colleagues and friends worldwide during the last minute death battle in December 2003.

(This is the end of the part 3 of this part 4 series, P)
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pandaneko
post Jan 31 2012, 10:19 AM
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QUOTE (pandaneko @ Jan 19 2012, 05:28 PM) *
What follows is the URL of the ISAS pages I am about to ranslate for some time to come.

http://www.isas.jaxa.jp/j/enterp/missions/...status_01.shtml

Its rough title is something like "what Nozomi may have left for the success of future international planetary missions".


I have had a look again at what I undertook in terms of translation re Nozomi. Part 4, the last part of the ISAS newsletter 4 part series, happens to be all about 15 instruments on board. I was in two minds as to whether I should translate them.

The biggest reason, of course, is that it now seems silly and useless to translate what all these instruments may have performed simply because the whole thing blew up (excuse me here because I had had only a very quick glance at that time when I undertook to translate this 4 part series and I was not aware exactly what the last part of this series contained!).

However, having translated the main text of this series and finding myself being in full sympathy with the author, I will continue to finish translating what remains in the series. It is only a few evenings work! This will come after my translation of another ISAS newsletter for this evening which effectively contains an ISAS version of Nozomi failure press release, as follows.

Nozomi made swing-bys by the Moon on 24 August and 8 December 1998. On 20 December Nozomi made another swing-by with the Earth at a distance of 1000 km, but Nozomi developped an insufficient propulsion due to the the mulfunction of its thruster valve.

Flight course was corrected, but this led to an over-use of the fuel and it became impossible to insert Nozomi into the Mars transfer orbit. For that reason, the arrival timing was delayed from October 1999 to January 2004.

Nozomi was placed into an orbit, after the Earth swing-bys in December 2002 and June 2003, which would have directed Nozomi towards Mars. However, Nozomi developped another mulfunction with the comms. and thermal control system in April 2003 and franctic efforts on the ground could not recover these difficulties.

A command was sent out on 9 December to change its orbit in order to ensure that Nozomi would not collide with Mars for fear of contamination of the planet in accordance with an international agreenment.

P

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