Author Topic: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011  (Read 425980 times)

Offline jimvela

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #820 on: 11/11/2011 08:18 PM »
No backup for Cassini, Galileo, Magellan, the MERs, Curiosity, CONTOUR, New Horizons, MRO...

No backup for Deep Impact, Kepler, WISE, NPP, JWST, SiRTF,......

The only close thing today is cancelled missions that have a bus recycled for a future mission.

Offline iamlucky13

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #821 on: 11/11/2011 08:27 PM »
Thanks guys. What a mess this all is! I miss the days of shuttle, because if one of the orbiter's sneezed, you'd have 15 PRCB presentations and by the second IPR coverage to play with :)

It almost seems like we had clearer information on the X-37.  ;D

There are many NEO's that take much less delta-V to reach than Phobos. It has the basic capability to approach such an object and land.

Forget about it. There are very few windows for NEOs even at low delta-v.

That's one of the dirty little secrets in all the talk about human missions to NEOs. Right now the target set is bad. Really small. Gotta do a better survey and find more targets.

Are you saying it is definitely not be possible to park the spacecraft in earth-orbit to await a window? I'm having to rely on other's numbers here, but if reaching Phobos takes 7.6 km/s (source) and some NEO's take only 3-4 km/s, that suggests a lot of potential planning flexibility.

Offline Sparky

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #822 on: 11/11/2011 08:49 PM »
I have an admittedly dumb question/idea.

YH1. What sort of maneuvering capability does it have? Could it be turned on inside the truss, and if so, used to slowly reorient, or conceivably adjust the orbit of FG? I realize that this is like using an electric scooter to move a dump truck, but I thought I'd ask.

Online hop

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #823 on: 11/11/2011 08:57 PM »
YH1. What sort of maneuvering capability does it have? Could it be turned on inside the truss, and if so, used to slowly reorient, or conceivably adjust the orbit of FG? I realize that this is like using an electric scooter to move a dump truck, but I thought I'd ask.
Regardless of maneuvering capability, I would expect any activation of YH1 to require commanding FG first.

Offline ChileVerde

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #824 on: 11/11/2011 09:11 PM »

Edit: According to the last 2 elsets (sharply decreasing decay parameter measured in rev/day˛), re-entry date has been pushed forward back, ie it will occur later(using SatEvo)

I just checked using the latest two TLEs, and SatEvo is showing Jan 3 or 4.  Not too much should be made of that, but it's probably indicative of "end of the year" rather than "end of the month."
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Offline simonbp

Source: http://satobs.org/seesat/Nov-2011/0110.html

"Phobos-Grunt: latest two TLEs suggest manoeuvring or venting"

Or, simply the orbit is being better constrained by more observations. IMHO that's more likely...

Offline olasek

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #826 on: 11/11/2011 10:26 PM »
I repeat, look at the history of the Hayabusa mission before you call recovery dependent on a
This is a complete joke to draw any parallels with that mission. That spacecraft was not DEAD to begin with, that was a very well functioning probe for months. That was also a Japanese technology to begin with, far too more advanced in terms of electronics and overall mission preparation and attention to detail. I repeat it is an utter joke to dream that PG could turn into Hayabusa, even Russian officials acknowledged this problem is not some sort of a software 'glitch' but most likely a serious hardware flaw.
« Last Edit: 11/11/2011 10:56 PM by olasek »

Offline Prober

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #827 on: 11/11/2011 10:48 PM »
Source: http://satobs.org/seesat/Nov-2011/0110.html

"Phobos-Grunt: latest two TLEs suggest manoeuvring or venting"

Or, simply the orbit is being better constrained by more observations. IMHO that's more likely...

Don't know that much about orbits ......but looks like this one has changed since yesterday.......she just hit over two hundered miles up over Indoensia,and 216 over auz, then drops like 60 miles.  Hit Alt of 142 over Peru
« Last Edit: 11/11/2011 11:30 PM by Prober »
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The new article for Fobos-Grunt, to be specific on the problem and link better to this update thread than the launch article:

http://www.nasaspaceflight.com/2011/11/russian-engineers-stricken-fobos-grunt-spacecraft/

Took some of William's article on the hardware, summarized where things stand and made it a bit more interesting by noting the NASA interest in crewed missions to Phobos as it tied in nicely.

As pre previous request, if anyone sees something where I've been too liberal with the facts, let me know on here or via PM (to save me the shame ;))

Offline iamlucky13

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #829 on: 11/11/2011 10:59 PM »
I repeat, look at the history of the Hayabusa mission before you call recovery dependent on a
This is a complete joke to draw any parallels with that mission. That spacecraft was not DEAD to begin with. That was a Japanese technology to begin with, far too more advanced in terms of electronics and overall mission preparation. I repeat it is an utter joke to dream that PG could turn into Hayabusa.


There has been no indications that F-G is dead.

Look, every person on this forum recognizes the odds of Fobos-Grunt being recovered are slim. For all we know, it may in fact be dead.

However, no one on this forum, yourself included, or probably in Russia for that matter, based on their ongoing attempts to contact it, are privy to any information that whatever is wrong with it is irrecoverable or that it is in fact dead.

Regardless, let's get a clear statement of your position so as to avoid going around in circles - do you advocate giving up the probe entirely at this point?

Online hop

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #830 on: 11/11/2011 11:05 PM »
That spacecraft was not DEAD to begin with.
There's no confirmation that PG is dead either. Hayabusa was out of control and out of communication several times, so there is some parallel. The chances are very slim IMO, but available information doesn't appear to justify declaring PG dead yet.

Speaking of Japanese mission, Nozomi might be another example to consider if control is reestablished without the ability to proceed on the nominal trajectory. An extended cruise + earth flyby like that is probably more viable than trying to go to a NEO.
« Last Edit: 11/11/2011 11:06 PM by hop »

Offline iamlucky13

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #831 on: 11/11/2011 11:10 PM »
As pre previous request, if anyone sees something where I've been too liberal with the facts, let me know on here or via PM (to save me the shame ;))

It looks good to me. I'm in no better position than you, following what other sources have written, but it seems consistent with the discussion so far.

The flexible path tie-in was worked in nicely.


Offline Rocket Science

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« Last Edit: 11/12/2011 12:23 AM by Rocket Science »
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Offline Galactic Penguin SST

Can anyone computer expert here judges the possibility of the DST problem? Something like this?

http://datasheets.maxim-ic.com/en/ds/DS12885-DS12C887A.pdf


Quote
Bit 0: Daylight Saving Enable (DSE). This bit is a
read / write bit that enables two daylight saving adjustments
when DSE is set to 1. On the first Sunday in
April, the time increments from 1:59:59 AM to 3:00:00
AM. On the last Sunday in October when the time first
reaches 1:59:59 AM, it changes to 1:00:00 AM. When
DSE is enabled, the internal logic test for the first / last
Sunday condition at midnight. If the DSE bit is not set
when the test occurs, the daylight saving function does
not operate correctly. These adjustments do not occur
when the DSE bit is 0. This bit is not affected by internal
functions or RESET.
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Online CitabriaFlyer

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #835 on: 11/12/2011 12:52 AM »
Had this mission launched a few years ago (prior to STS-125 after which the shuttle lost 39B and the ability to put two shuttles on pads simultaneously) how difficult would it have been to have mounted a rescue?

Seems like it would be difficult to plan a mission and fly it before this launch window expires.

Seems more likely the spacecraft could have been retrieved, returned to Earth, and flow for the next launch window.

Maybe not a practical topic for discussion on this forum, but fun to think about nonetheless.

Offline A_M_Swallow

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #836 on: 11/12/2011 12:53 AM »
Can anyone computer expert here judges the possibility of the DST problem? Something like this?

http://datasheets.maxim-ic.com/en/ds/DS12885-DS12C887A.pdf


Quote
Bit 0: Daylight Saving Enable (DSE). This bit is a
read / write bit that enables two daylight saving adjustments
when DSE is set to 1. On the first Sunday in
April, the time increments from 1:59:59 AM to 3:00:00
AM. On the last Sunday in October when the time first
reaches 1:59:59 AM, it changes to 1:00:00 AM. When
DSE is enabled, the internal logic test for the first / last
Sunday condition at midnight. If the DSE bit is not set
when the test occurs, the daylight saving function does
not operate correctly. These adjustments do not occur
when the DSE bit is 0. This bit is not affected by internal
functions or RESET.

The change over date was in October so most systems should have sorted themselves out by now.  I suppose there may be a subsystem that is applying a 1 hour correction and say looking for the stars in the wrong place - to prevent this sort of problem the military use GMT through out the year.

If this is sister to the Millennium Bug similar hacks can be used to get round it.  In one organisation the operators told their computers that it was 1998.  The equivalent would be to tell the probe that this month is August.  (Check the effect of the wrong date on the guidance system.)  The date could stay wrong or be corrected on its way to Mars.

Online hop

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #837 on: 11/12/2011 12:54 AM »
Can anyone computer expert here judges the possibility of the DST problem? Something like this?
I rate that as zero. There would be no reason to use onboard clocks with any DST adjustment, and sequence development would also be done against some fixed standard like GMT. I guess it's theoretically possible that some higher level confusion could ultimately lead to an incorrect sequence, but there's no evidence to suggest that is the case, and certainly no reason to suspect that over a million other possible errors.

I did see a rumor or joke floating around somewhere (from one of the Russian forums maybe ?) somehow tying this to the fact the Russians decided to stop using DST (they didn't "fall back" this year), but I don't see any reason to give it any credence.


Online hop

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #838 on: 11/12/2011 12:55 AM »
The change over date was in October
Not in Russia or the US.

Offline alk3997

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #839 on: 11/12/2011 01:46 AM »
Had this mission launched a few years ago (prior to STS-125 after which the shuttle lost 39B and the ability to put two shuttles on pads simultaneously) how difficult would it have been to have mounted a rescue?

Seems like it would be difficult to plan a mission and fly it before this launch window expires.

Seems more likely the spacecraft could have been retrieved, returned to Earth, and flow for the next launch window.

Maybe not a practical topic for discussion on this forum, but fun to think about nonetheless.

Let me see if I can help with your question.  Under normal circumstances it took about 2 years to design a Shuttle mission.  This was if everything went well.  We didn't just drop some SRBs on the mobile crawler, slap a tank between then and then run the orbiter up the side.  It took lots of planning, analysis and checking to make sure everything would work right (or at least had a reasonable chance of everything working right).

Don't forget there is crew training.  Not just the learning to fly but the parts about what to do once you got to the objective.

In the case of this supposed "rescue" mission.  What was the objective?  To bring up a new upper stage or to magically fix the spacecraft?  If it is the former, someone would have to make the new upper stage and a cradle for the cargo bay as well as the design safe and arm circuitry - among a whole slew of things.  If it is the latter objective, then how do you fix the spacecraft?  Kind of hard to train for a spacecraft rescue when no one knows what went wrong.  If you're just up there to take a look, that doesn't buy you anything since you would probably not have the right equipment to fix the problem.

I believe if we were repeating a mission with the same orbiter (each orbiter had unique parameters), we could have done it in 2-3 months (see STS-94) but something new and untried - I'd guess about 2 years.

I might argue the supposed cost of a Shuttle flight from a few pages back (the real number depends upon who gets charged and how much of the cargo bay was used), but it isn't relevent because this rescue mission during the same launch window couldn't be done, no matter how much money was available.

So you would have as much chance as the President of the United States and the four Beatles performing the rescue mission themselves as you would being able to launch this so-called rescue mission during the current launch window.
« Last Edit: 11/12/2011 01:54 AM by alk3997 »

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