Author Topic: Fobos-Grunt EOM Re-Entry Latest (Read 224502 times)

Chris Bergin · « **Reply #240 on:** 01/15/2012 05:55 pm »

So we ended with:

Troubleshooting thread 1 was 460 posts and 177,000 reads, requiring troubleshooting thread 2, which reached 1057 posts and 220,000 reads, but we're no longer in troubleshooting for this poor spacecraft

This latest thread will cover the updates through to the spacecraft's re-entry (End of Mission - EOM).

Resources:

Pre-Launch:
http://forum.nasaspaceflight.com/index.php?topic=15610.0

Launch Updates:
http://forum.nasaspaceflight.com/index.php?topic=15610.165

Launch Article:
http://www.nasaspaceflight.com/2011/11/live-zenit-2launch-fobos-grunt-sample-return-mission-to-phobos/

Post S/C Sep, leading into notes of a problem:
http://forum.nasaspaceflight.com/index.php?topic=15610.330

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

Troubleshooting Updates 2:
http://forum.nasaspaceflight.com/index.php?topic=27289.0

Article: Fobos-Grunt recovery efforts underway after telemetry is received:
http://www.nasaspaceflight.com/2011/11/live-fobos-grunt-recovery-efforts-underway/

Article: Hope lost for Fobos-Grunt – likely to re-entry early in New Year:
http://www.nasaspaceflight.com/2011/12/hope-lost-fobos-grunt-re-entry-early-new-year/

Article: Fobus-Grunt ends its misery via re-entry
http://www.nasaspaceflight.com/2012/01/fobus-grunt-ends-its-misery-via-re-entry/

RIP Fobos-Grunt.

jcm · « **Reply #241 on:** 01/15/2012 05:57 pm »

A new Novosti report says some Russian sources put reentry a little later, 1759 UTC
at 49.3W 18.2S in the Atlantic ]edit - that's actually in Brazil!!] - so story may not be completely over.

Svetoslav · « **Reply #242 on:** 01/15/2012 06:08 pm »

I just read the RIA Novosti source : http://ria.ru/science/20120115/540143795.html

(Not far from the shore of Brazil), which means still in water

desktopsimmer · « **Reply #243 on:** 01/15/2012 06:18 pm »

Quote from: Chris Bergin on 01/15/2012 05:55 pm

...RIP Fobos-Grunt.

Re-entry In Pieces?

collectSPACE · « **Reply #244 on:** 01/15/2012 06:29 pm »

Quote from: Space Pete on 01/15/2012 05:00 pm

Does anyone know whether the P-G sample return capsule contains a transponder? How were they intending to find it assuming a nominal mission & return to Earth - surely not just visually?

According to: http://www.russianspaceweb.com/phobos_grunt_scenario.html

From the outset, Russian developers decided not to rely on any active landing systems, such as radio-beacons, to locate and recover the tiny vehicle... Instead, ground-based radar and optical observations would be the sole means of tracking the vehicle during reentry and of pinpointing the site of its touchdown.

jcm · « **Reply #245 on:** 01/15/2012 06:32 pm »

Quote from: Svetoslav on 01/15/2012 06:08 pm

I just read the RIA Novosti source : http://ria.ru/science/20120115/540143795.html

(Not far from the shore of Brazil), which means still in water

Yes, but the numerical lat and long quoted in this source do not seem to be consistent with that statement - or their Google Maps are different from mine...

Svetoslav · « **Reply #246 on:** 01/15/2012 06:54 pm »

Hm...

http://twitter.com/PhG_Reentry

Twitter account also says Brazil. I wonder if they copy from NSF

sdsds · « **Reply #247 on:** 01/15/2012 06:57 pm »

Quote from: jcm on 01/15/2012 06:32 pm

Quote from: Svetoslav on 01/15/2012 06:08 pm
I just read the RIA Novosti source : http://ria.ru/science/20120115/540143795.html

(Not far from the shore of Brazil), which means still in water

Yes, but the numerical lat and long quoted in this source do not seem to be consistent with that statement - or their Google Maps are different from mine...

The source seems to report "310.7 degrees east longitude and 18.2 degrees south latitude" but 31.7E fits the description of the location better.

astropl · « **Reply #248 on:** 01/15/2012 07:02 pm »

Quote from: sdsds on 01/15/2012 06:57 pm

The source seems to report "310.7 degrees east longitude and 18.2 degrees south latitude" but 31.7E fits the description of the location better.

And 49.3W much better

Rahkashi · « **Reply #249 on:** 01/15/2012 07:16 pm »

That's too bad. RIP Fobos-Grunt, and my condolences to anyone who worked on this project.

Does anyone know what part of the Pacific she came down in? Was there any islands nearby that could have gotten video?

jcm · « **Reply #250 on:** 01/15/2012 07:30 pm »

Quote from: astropl on 01/15/2012 07:02 pm

Quote from: sdsds on 01/15/2012 06:57 pm

The source seems to report "310.7 degrees east longitude and 18.2 degrees south latitude" but 31.7E fits the description of the location better.

And 49.3W much better

I am informed that this report is probably in error (based on the center of an older Roskosmos reentry prediction). The 1745 UTC (plus or minus how much?) seems like a more reliable report pending better info from Space-Track

jcm · « **Reply #251 on:** 01/15/2012 07:46 pm »

SpaceTrack just reported that the vehicle "decayed inside the predicted window", i.e. between 1659 and 1747 UTC (their last prediction range). So, consistent with the 1745 value but not super helpful.

jcm · « **Reply #252 on:** 01/15/2012 07:50 pm »

The 1759 UTC figure comes from Russian "ballistics experts", so presumably extrapolating previous tracking data using an atmospheric model and assumptions
about the spacecraft breakup. The 1745 figure comes from Russian "space control network", but it's not clear to me what assets they have in that part of the world (no Russian radars in South America!) or whether data from their US-K early warning satellites can be incorporated (as far as I know they don't have any working ones anyway). So it's very unclear upon what data these conclusions are really based.

JimO · « **Reply #253 on:** 01/15/2012 08:02 pm »

Quote from: jcm on 01/15/2012 07:50 pm

The 1759 UTC figure comes from Russian "ballistics experts", so presumably extrapolating previous tracking data using an atmospheric model and assumptions
about the spacecraft breakup. The 1745 figure comes from Russian "space control network", but it's not clear to me what assets they have in that part of the world (no Russian radars in South America!) or whether data from their US-K early warning satellites can be incorporated (as far as I know they don't have any working ones anyway). So it's very unclear upon what data these conclusions are really based.

I second JCM's bafflement for which [if ANY] sensors were used for the Russian pronouncement. It sounds like another self-serving 'safe in the Pacific' allegation aimed at Western anxieties, not at realities.

Considering that the overflight across Argentina/Brazil was in daylight, it may be too much to expect fireball reports [as we fortunately got for Mars-96 crossing the coast in 1996], but the population density is high enough along the corridor that reports of sonic booms could be relevant.

JimO · « **Reply #254 on:** 01/15/2012 08:37 pm »

Let's be precise. Russian Defense Ministry spokesman did NOT say that the probe crashed at that specified location in the Pacific. His exact words were:

"По расчетным данным Главного центра разведки космической обстановки Войск ВКО, падение фрагментов аппарата "Фобос-Грунт" должно было произойти в 21:45 мск в акватории Тихого океана...",

In translation, this means, "From calculated data of the main space surveillance center of the Space Troops, the fall of fragments of F-G SHOULD HAVE occurred at 21:45 Moscow Time..."

The announced location was NOT observed by any Russian sensor and Zolotukhin is not claiming it was.

JimO · « **Reply #255 on:** 01/15/2012 08:39 pm »

Are there also available insights in how far down track debris is scattered from the 'decay point'? 300km? 500km? 1000km?

jcm · « **Reply #256 on:** 01/15/2012 09:03 pm »

Quote from: JimO on 01/15/2012 08:37 pm

Let's be precise. Russian Defense Ministry spokesman did NOT say that the probe crashed at that specified location in the Pacific. His exact words were:

"По расчетным данным Главного центра разведки космической обстановки Войск ВКО, падение фрагментов аппарата "Фобос-Грунт" должно было произойти в 21:45 мск в акватории Тихого океана...",

In translation, this means, "From calculated data of the main space surveillance center of the Space Troops, the fall of fragments of F-G SHOULD HAVE occurred at 21:45 Moscow Time..."

The announced location was NOT observed by any Russian sensor and Zolotukhin is not claiming it was.

Very interesting. The article
http://www.yuga.ru/news/250482/
on the 'ballistics experts' could be read either way I think - and my Russian is not as good as yours I admit - but probably both values are derived from estimates analogous to SatEvo and so on, and not from actual data proving reentry occurred.

The SpaceTrack TIP message can perhaps be seen as more definitive, otherwise should we still be encouraging people to observe just in case the Russian calculations are wrong?

Chris Bergin · « **Reply #257 on:** 01/15/2012 11:23 pm »

No word of people seeing anything in the sky (as much as it was daylight), and one would have assumed so by now if it had gotten near a landmass like Brazil.

Antares · « **Reply #258 on:** 01/16/2012 02:33 am »

Slightly ironic that it came down on the 6th anniversary of the successful Stardust sample return.

olasek · « **Reply #259 on:** 01/16/2012 03:27 am »

Quote from: JimO on 01/15/2012 08:39 pm

Are there also available insights in how far down track debris is scattered from the 'decay point'? 300km? 500km? 1000km?

Instead of talking about a 'decay point' (which is not well defined to begin with) it is better to ask simply about the general size of the area covered by debris. In the case of STS Columbia it was just about a 200 nm long thin elipsoid.