I wonder if we could provide some small summary of where we are, as I really need to get a new article on (as opposed to what is the launch day article currently on site). So I'm going to write a shortish state of play summary and give it a bit of a fresh look by adding NASA's interest in Phobos.I just need to check what we appear to have as facts - and no more, the thread is for NK comments, speculation, etc:We had nominal Zenit-2 first and second stage performance.First - and obviously the second - burn on the Fregat-derived stage did not occur, because the flight computer went into safe mode (reason unknown).Recovery of the computer has been unsuccessful - partly because of antenna issues (I'm not clear on this element) - during all passes thus far.They do have more than the three days as the solar panels are extended and sun-facing.However, it is expected to re-enter at the end of the month if this is a Loss of Mission scenario due to decaying orbit.Much appreciated if anyone can tick some boxes/correct me - I'd be a fool to not ask and end up making a basic mistake in an article.
Quote from: Chris Bergin on 11/11/2011 06:42 pmI wonder if we could provide some small summary of where we are, as I really need to get a new article on (as opposed to what is the launch day article currently on site). So I'm going to write a shortish state of play summary and give it a bit of a fresh look by adding NASA's interest in Phobos.I just need to check what we appear to have as facts - and no more, the thread is for NK comments, speculation, etc:We had nominal Zenit-2 first and second stage performance.First - and obviously the second - burn on the Fregat-derived stage did not occur, because the flight computer went into safe mode (reason unknown).Recovery of the computer has been unsuccessful - partly because of antenna issues (I'm not clear on this element) - during all passes thus far.They do have more than the three days as the solar panels are extended and sun-facing.However, it is expected to re-enter at the end of the month if this is a Loss of Mission scenario due to decaying orbit.Much appreciated if anyone can tick some boxes/correct me - I'd be a fool to not ask and end up making a basic mistake in an article.Chris to play devils advocate here, since there was no telemetry during the critical events do we know that? Do we know that the first burn not occurring was due to the computer being in safe mode? Is it possible something else caused the burn to abort and that triggered safemode?Do we know that the solar panels are extended and sun facing? Based on amateur observers we know the vehicle is stable and not tumbling.Also did you read Ted Molczan's post ( http://satobs.org/seesat/Nov-2011/0116.html ) that oddly the two TLE's may point to a Delta V of ~1.3 while over Baikonur?Anywho looking forward to the article.
Quote from: iamlucky13 link=topic=15610.msg828128#msg828128 my post reflected the extreme end of optimism,....... if they are perhaps able to recover the spacecraft but not in time to reach Mars it wouldn't be possible to even consider other missions.because your first IF in itself borders on miracle, I separate 'miracle' from optimism, I would never for example say I am optimistic that I could win a lottery ticket where odds are 1:10000000 because IMHO such a statement would sound nonsensical. As to your second assertion spacecrafts are built for a concrete missions, they are highly specialized, and it is mpossible to think how such Phobos- Grunt could be reused in Earth orbit (or any orbit outside of Mars) earthly satellites are considered often a 'total loss' if their orbits are slightly off (insurance covers total amount) and PG would still be a junk even if you managed to turn on it's cameras or instruments, I am running out of breath....
my post reflected the extreme end of optimism,....... if they are perhaps able to recover the spacecraft but not in time to reach Mars it wouldn't be possible to even consider other missions.
Now that the subject of explosions has come up, let me ask this: if F-G remains stuck in its decaying orbit and at least one tank is already venting, what is the likelihood of more leaks leading to a hypergolic mix that triggers a chain reaction of larger and larger explosions? How much more/less likely is an orbital debris impact that triggers likewise?If it happens, does the secret US death ray laser get blamed? Or the Chinese one?If it happens, how energetic could some of the fragments be ejected forward? That is, could they reach ISS altitude and add to the already pesky Chinese ASAT debris threat?Is an on-orbit explosion a 'happy ending'
Jim O, any potential explosion would be in a low orbit and even though it would be energetic and boost some debris apogees, the perigees of the debris would still be the low point it occurred at and just like Phobos-Grunt not have a long orbital lifetime.
Sorry if I missed anything - is a venting tank speculation or based on a credible rumor?
I just need to check what we appear to have as facts - and no more, the thread is for NK comments, speculation, etc:
We had nominal Zenit-2 first and second stage performance.First - and obviously the second - burn on the Fregat-derived stage did not occur,
because the flight computer went into safe mode (reason unknown).
Recovery of the computer has been unsuccessful - partly because of antenna issues (I'm not clear on this element) - during all passes thus far.
They do have more than the three days as the solar panels are extended and sun-facing.
Adjusted analysis of the orbital parameters and energy supply on board showed that these commands must be issued within 2 weeks.
However, it is expected to re-enter at the end of the month if this is a Loss of Mission scenario due to decaying orbit.
However, it is expected to re-enter at the end of the month ...
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.
With American probes it seems to be common practice to build a flight vehicle and at least one backup vehicle. The backup vehicle is kept up-to-date and configured identically to the flight vehicle, assisting in troubleshooting and analysis. Is this a Russian practice as well?
No backup for Cassini, Galileo, Magellan, the MERs, Curiosity, CONTOUR, New Horizons, MRO...