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Can Nozomi enter Mars orbit?
People have hailed the upcoming arrival at Mars of NASA's two Mars
landers, Mars Express (with Beagle 2), and Japan's Nozomi. The Nozomi team has managed to pull off quite a few workarounds for problems they've had. Quite impressive. But based on recent reports, I wonder if their luck is running out. In a nutshell, here is the problem as I understand it: However, in late December 2003/early January 2004 the craft must fire its onboard thrusters to enter Mars orbit. The heating system will be required for this manuever, ISAS will be attempting to recover use of the heating system by recycling the onboard electronics hundreds of times to try to eliminate the short. If the heating system is working, Nozomi will be inserted into a highly eccentric Mars orbit http://nssdc.gsfc.nasa.gov/database/...g?sc=1998-041A And my question is: have they had any success in reviving the heating system? Unless I misunderstand the reports, they've been trying since July or so, and have not succeeded to date. Furthermore, I would think that recycling the electronics hoping to eliminate a short would be, well, far from assured of success. Can any of Nozomi's instruments get useful data from a flyby only? There has been some confused reporting in recent days about whether Nozomi is in danger of hitting Mars. See for example http://www.planetary.org/html/news/a..._11-14-03.html or http://www.space.com/missionlaunches...te_031115.html . But that isn't the real issue. In order to enter orbit, Nozomi needs not just the ability to do a trajectory correction (which I'm not sure is in doubt), but also needs to be able to perform a Mars insertion burn. Various stories: http://www.marsnews.com/missions/nozomi/ |
#2
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Can Nozomi enter Mars orbit?
Jim Kingdon writes:
[...] if their luck is running out. In a nutshell, here is the problem as I understand it: However, in late December 2003/early January 2004 the craft must fire its onboard thrusters to enter Mars orbit. The heating system will be required for this manuever, ISAS will be attempting to recover use of the heating system by recycling the onboard electronics hundreds of times to try to eliminate the short. If the heating system is working, Nozomi will be inserted into a highly eccentric Mars orbit http://nssdc.gsfc.nasa.gov/database/...g?sc=1998-041A And my question is: have they had any success in reviving the heating system? Unless I misunderstand the reports, they've been trying since July or so, and have not succeeded to date. Furthermore, I would think that recycling the electronics hoping to eliminate a short would be, well, far from assured of success. I agree with your summary and conclusion, and, no, they have had no success in reviving the heating system. The hydrazine supply previously froze and only thawed when Nozomi moved closer to the sun, and it is thought to be frozen again as Nozomi has receded from the sun, which is why the heating system is required. Can any of Nozomi's instruments get useful data from a flyby only? I don't know if they could if they were working, which they are not, and it's not at all clear (I would say "extremely doubtful") that the onboard power system is up to the task of powering the instruments at this point. The reporting on whether Nozomi is in danger (and how much danger) of hitting Mars is, as you said, confusing. My current impression is that the chance is not very high. I also believe that, while Nozomi's ground controllers haven't given up hope, hope is about all they have left, and there is no realistic chance of Nozomi either entering Martian orbit or performing any science at Mars. |
#3
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Can Nozomi enter Mars orbit?
I also believe that, while Nozomi's ground controllers haven't given
up hope, hope is about all they have left, and there is no realistic chance of Nozomi either entering Martian orbit or performing any science at Mars. Seems like it. Those behind Nozomi should be lauded for keeping it going as long as they did. Oberg has written a nice article which summarizes the situation: http://www.msnbc.com/news/996466.asp?0cv=CB20&cp1=1 The information isn't drastically new since my post on Thursday. But the spin is changing, and reading between the lines of http://www.isas.ac.jp/e/snews/2003/1120.shtml (as Oberg does) gives a pretty good idea that recovery is, well, "far from assured" would be a generous way of putting it. |
#4
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Can Nozomi enter Mars orbit?
A correspondent asks me whether Nozomi could be targeted to impact
Deimos or Phobos, a la Deep Impact. I don't know whether the controllers have enough control over Nozomi or not, to hit a relatively small target like that. But the bigger question is whether there is anything which has instruments which could detect anything interesting about the impact. The Moon has/had the Apollo seismometers, Deep Impact has an orbiter in addition to the impacter, etc. I'd be a bit surprised if Hubble, MGS, Mars Odyssey, etc, could even detect an impact of a small spacecraft on a Martian moon, much less measure something of scientific interest. |
#5
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Can Nozomi enter Mars orbit?
A better question is: what can Nozomi study while passing by Mars?
There should be *something* useful that the probe could do in its only flyby. Jim Kingdon wrote in message ... A correspondent asks me whether Nozomi could be targeted to impact Deimos or Phobos, a la Deep Impact. I don't know whether the controllers have enough control over Nozomi or not, to hit a relatively small target like that. But the bigger question is whether there is anything which has instruments which could detect anything interesting about the impact. The Moon has/had the Apollo seismometers, Deep Impact has an orbiter in addition to the impacter, etc. I'd be a bit surprised if Hubble, MGS, Mars Odyssey, etc, could even detect an impact of a small spacecraft on a Martian moon, much less measure something of scientific interest. |
#6
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Can Nozomi enter Mars orbit?
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