Author Topic: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011  (Read 249493 times)

Offline JimO

  • Veteran
  • Full Member
  • ****
  • Posts: 1562
  • Liked: 29
  • Texas, USA
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #435 on: 11/09/2011 04:24 AM »
http://www.interfax.ru/society/news.asp?id=215883

INTERFAX: Russian specialists have only three days to upload the new software before the batteries run out of power...

As I understand it, the solar panels do not unfold until AFTER the completion of the burns. But while folded, do they generate ANY 'trickle power'?

Another time constraint is the rate with which the probe's parking orbit is precessing -- about 6-7 degrees per day -- out of the optimal plane for insertion onto the trans-Mars trajectory. Each day means the need for a bigger burn to correct for the growing planar error.


Offline JimO

  • Veteran
  • Full Member
  • ****
  • Posts: 1562
  • Liked: 29
  • Texas, USA
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #436 on: 11/09/2011 04:28 AM »
.... according to the Space Review (http://thespacereview.com/article/1966/1) Phobos-Grunt "is the heaviest solar system explorer ever (more than twice the second-heaviest, Cassini).", not just the heaviest built in the former USSR.

I don't accept that claim, since the probe's mass is presented in LEO parking orbit, prior to insertion on the trans-Mars route. More than half of that mass disappears by the time it's on interplanetary cruise.

But the mass IS a critical issue, BECAUSE it's now of the heaviest satellites that might randomly fall back to Earth. If a controlled de-orbit can't be accomplished, we're talking about a spacecraft reentry within a week or two far more hazardous than the recent high-fear-factor falls of UARS and others, aren't we?


Offline slavnus

  • Member
  • Posts: 6
  • Liked: 0
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #437 on: 11/09/2011 05:14 AM »
prelaunch report from Baikonur



Everybody fingers crossed!!!


Offline JimO

  • Veteran
  • Full Member
  • ****
  • Posts: 1562
  • Liked: 29
  • Texas, USA
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #438 on: 11/09/2011 05:25 AM »
Apparently there's a few grams of radioactive cobalt-57 in one of the soil analysis instruments. Doesn't look like any significant contamination threat if/when it falls back to Earth.
http://vz.ru/news/2011/11/9/537080.print.html
http://www.ria.ru/science/20111109/484486608.html


Offline jcm

  • Senior Member
  • *****
  • Posts: 2157
  • Liked: 18
  • Jonathan McDowell
  • Somerville, Massachusetts, USA
    • Jonathan's Space Report
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #439 on: 11/09/2011 05:34 AM »
Not sure if this is the best place to bring it up but I'm a little confused by the article, specifically the translation. Fobos is not the name of the martian moon, it's Phobos. The Russian letter "ф" is pronounced similarly to "f," but we're not talking about some place called Fobos, we're talking about the Martian moon Phobos. A nitpicky point perhaps but I disagree that Roscosmos has been mistranslating the name of the mission.

Also, according to the Space Review (http://thespacereview.com/article/1966/1) Phobos-Grunt "is the heaviest solar system explorer ever (more than twice the second-heaviest, Cassini).", not just the heaviest built in the former USSR.


There's a confusion here between translation and transliteration.
If you want to TRANSLATE the probe's name, you should say "Phobos-Ground" or "Phobos-Soil". And you should refer to the Union-TM spaceship docking with the Star module, not the Soyuz-TM docking with Zvezda, etc...
but in TRANSLITERATION, which we normally do for names, it is useful to have a fixed mapping between the two alphabets (in this case Cyrillic and Roman) - this helps because if a reader knows both they can more reliably guess what the original Cyrillic was. Mapping the Russian letter Ф to the English letter F, rather than Ph, is a common choice - either would do as long as you are consistent, but in most Western space historiography we've picked F.

It's a Russian space probe, so I prefer to render the Russian spelling as best
I can. Now when I talk about the moon of Mars, that isn't Russian, and there's
already an English name for it, so when TRANSLATING a Russian statement I talk about the Fobos-Grunt mission to the moon Phobos.

When rendering names from another language or alphabet it's always a tricky choice - is the notorious late terrorist called Osama bin Laden, Usama bin Laden, or (translating)  Leonine Ladenson? Transliterating is usually a better choice than translating in my opinion.

Meanwhile... crossing my fingers that the team can save the mission, whatever its name is..
-----------------------------

Jonathan McDowell
http://planet4589.org

Offline Moe Grills

  • Full Member
  • ****
  • Posts: 546
  • Liked: 0
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #440 on: 11/09/2011 06:33 AM »
http://ria.ru/science/20111109/484413896.html

Unfortunately I bear once again some bad news...

Specialists are already working on two versions about why the spacecraft wasn't able to switch to Star orientation.

The first one is a programming mistake. If this is true - it can be corrected easily and the spacecraft will fly to Mars.

The second version - a hardware problem - failure of hardware components - like sensors... This would mean that Phobos-Grunt can't continue its trek to Mars.

If it's a hardware problem like sensors, wouldn't there be some redundancy built in to the system? Perhaps four sensors, instead of three? So if one fails the other three are sufficient?

Or, if one set of propellant valves fail on the Freget, would there be a
redundant set or bypasses?

I think that old saying is true: Give engineers the time to work out a problem, and they will....I hope it is this time.
I don't share in Jame Oberg's pessimism. 

Offline JimO

  • Veteran
  • Full Member
  • ****
  • Posts: 1562
  • Liked: 29
  • Texas, USA
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #441 on: 11/09/2011 06:44 AM »
I think that old saying is true: Give engineers the time to work out a problem, and they will....I hope it is this time.
I don't share in Jame Oberg's pessimism. 

Pessimistic? By no means. Nothing irreversibly bad has happened, the full prop load is still available, and short-term 'stay healthy' maneuvers can be performed.

Since the solar panels must be strong enough to perform Mars orbit insertion with the Fregat stage, it seems plausible that they can be deployed even before the Earth departure burn is made. That solves one problem. Going into a higher apogee orbit allowing more dwell time over Russian tracking sites solves another.

The major current problem is to get the spacecraft out of 'safe' mode. But such a mode is DESIGNED to be able to leave when you feel better.

I'll offer better than even odds that they WILL be able to make their interplanetary insertion -- maybe not tomorrow, and maybe not in three days, but within the launch window.

Right now I need to go get some sleep.


Offline JimO

  • Veteran
  • Full Member
  • ****
  • Posts: 1562
  • Liked: 29
  • Texas, USA
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #442 on: 11/09/2011 06:50 AM »
Roscosmos and NASA are both probably hoping that programming is not the issue. NASA JPL supplied the auxiliary flight control computer, at the request of the prime contractor with approval from Roscosmos, to increase chances of mission success. Both are turned on for launch through TMI with JPL computer taking over after last orbit correction burn to perform Mars System insertion. JPL computer is then turned off until Phobos launch of Sample return SC back to Earth.

This is the first I've ever heard of this JPL contribution. Is there any information on the JPL site?


I've made a medium-thorough search of the JPL site and can find NO menton of any JPL participation in the Fobos-Grunt spacecraft, much less a critical piece of guidance avionics. But then, I need sleep. Can anybody else try to vereify this claim about a 'secret' NASA contribution to the Russian program? 

Offline sdsds

  • Senior Member
  • *****
  • Posts: 3975
  • Liked: 126
  • "With peace and hope for all mankind."
  • Seattle
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #443 on: 11/09/2011 06:53 AM »
If a controlled de-orbit can't be accomplished, we're talking about a spacecraft reentry within a week or two far more hazardous than the recent high-fear-factor falls of UARS and others, aren't we?

Twitter user @OrbitOps reports having performed "quick calculations" and suggests re-entry would take placed "in about 130 days" if no control were possible.  My main hope is of course that the Fobos-Grunt mission controllers fix their little problem and light this candle.  But even if the main engine simply will not ignite, wouldn't they still have their RCS thrusters to effect a controlled entry?
-- sdsds --

Offline JimO

  • Veteran
  • Full Member
  • ****
  • Posts: 1562
  • Liked: 29
  • Texas, USA
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #444 on: 11/09/2011 06:57 AM »
Here's a pessimistic thought -- if they CANNOT regain control of the bird, and it heads for an uncontrolled entry, the hypergolics it carries -- about seven tons of nitrogen teroxide and hydrazine, which could freeze before ultimately entering -- will make it the most toxic falling satellite EVER. Old USA-193 will pale in comparison, as would Mars-96 and the plutonium it dumped on Bolivia in 1996.

Any wild and crazy estimates of orbital lifetime if it becomes a derelict?

Online Galactic Penguin SST

  • Geek Penguin in Earth Orbit
  • Senior Member
  • *****
  • Posts: 3966
  • Liked: 152
  • Hong Kong
A trampoline relying on one's opponents to work is still better than a trampoline that fails every few jumps. - 2014.05.15

Offline plutogno

  • Full Member
  • ****
  • Posts: 431
  • Liked: 12
  • Toulouse, France and Milan, Italy
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #446 on: 11/09/2011 07:50 AM »
Someone on NK posted that the solar arrays have been deployed. Hope it's true....

not sure it's good if true. it depends whether the attitude control system is designed for a firing with highly flexible appendages deployed

Online William Graham

  • Senior Member
  • *****
  • Posts: 3834
  • Liked: 2
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #447 on: 11/09/2011 08:51 AM »
Not sure if this is the best place to bring it up but I'm a little confused by the article, specifically the translation. Fobos is not the name of the martian moon, it's Phobos. The Russian letter "ф" is pronounced similarly to "f," but we're not talking about some place called Fobos, we're talking about the Martian moon Phobos. A nitpicky point perhaps but I disagree that Roscosmos has been mistranslating the name of the mission.

They're translating "Phobos" correctly, but "Грунт" does not translate to "Grunt". You can either translate the name to "Phobos-Soil" or "Phobos-Ground", or you can transliterate to "Fobos-Grunt" (the latter being standard for virtually all other Russian and Chinese spacecraft). Roskosmos are effectively translating the first half of the name, and just transliterating the second half, which is wrong. There a few cases where transliterated and translated rocket and spacecraft names are the same (Proton, Progress, etc), so I'm guessing that Roskosmos thought this was anoher such case, which it wasn't.
« Last Edit: 11/09/2011 08:54 AM by GW_Simulations »

Offline BrunoQuiocca

  • Member
  • Posts: 19
  • Liked: 0
  • Brazil
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #448 on: 11/09/2011 09:06 AM »
Guys! Found a brazillian video of the Phobos Grunt made last night.
His position is Lat: Lon-23.552XX: Alt-46.184XX: 742m, 467 miles ENE from me.

this is the video:
#

What he says: 1:08 Found the son of a b***

So I was wrong when i said that the two objects were taking distance from each other. On the beginning of his video the distance of them is about the same as what i saw.

Offline NH2501

  • Member
  • Posts: 9
  • Liked: 0
Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #449 on: 11/09/2011 09:09 AM »
Regarding translations and transliteration.

Fortunately, in Polish we don't have such a problem because of common language group for Polish (West Slavian) and Russian (East Slavian).
In both of them the correct name for Greek god of fear is Fobos (F equals letter and sound like Greek Φ, and ф in Russian!). We also both use noun "grunt" to describe a top/upper layer of soil or ground or contact area between building and ground.

Thanks to all contributors of this topic, by the way.
Greetings,
NH2501

Tags: