Author Topic: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011  (Read 641580 times)

Offline Danderman

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #780 on: 11/11/2011 05:03 pm »
I don't understand the purpose of the low-gain antennas on the MDU. Were they intended to play a role in the cruise phase of the mission, or were the high-gain antennas on the lander supposed to deploy and take over communications? If the LGAs were primarily intended for communications before the deployment of the HGAs, then how could they rationalize the placement of the LGAs where they would be blocked by the auxiliary propellant tank?

My opinion here:

Lack of systems engineering. The stack is a kludge, thrown together to save money. No one set out requirements for dealing with a situation where the Fregat/MDU did not perform the first two burns.

In particular, the novel configuration of the Fregat being controlled by the payload was not fully examined.


Offline hop

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #781 on: 11/11/2011 05:05 pm »
I sure hope that the Russians don't think that way. Maybe some of them might hope that an American failure would take attention away from them. But fundamentally, this is not a zero-sum game where one group loses and the other gains. Success helps everybody, and failure hurts everybody.
I think the the actual science community, this is very clear. Nobody want's to see someone else mission fail. Plus they have an instrument on Curiosity....

Quote
I sure hope that heads do not roll. That's not the way to improve the organization. The next time the Russians build a planetary mission, it would help if they actually have some people who learned from their mistakes and are paranoid about not repeating them. This is a learning experience, but only if the students don't get expelled.
Agreed, the Russians have shown over and over that this kind of punitive bloodletting is not particularly effective in solving systemic problems. Conversely, NASA has taken the opposite approach with great effect.

Offline iamlucky13

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #782 on: 11/11/2011 05:22 pm »
Quote
I sure hope that heads do not roll. That's not the way to improve the organization. The next time the Russians build a planetary mission, it would help if they actually have some people who learned from their mistakes and are paranoid about not repeating them. This is a learning experience, but only if the students don't get expelled.
Agreed, the Russians have shown over and over that this kind of punitive bloodletting is not particularly effective in solving systemic problems. Conversely, NASA has taken the opposite approach with great effect.

I will probably at some point in the future quote you on this. I see the, "I hope someone is getting fired for this failure" comment all the time, in many different scenarios.

Sometimes people do screw up in ways that aren't excusable, but in space exploration, there's a million subtle ways to get bitten that turn into valuable learning experiences.

Offline kevin-rf

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #783 on: 11/11/2011 05:26 pm »

My opinion here:

Lack of systems engineering. The stack is a kludge, thrown together to save money.

Prove it... More than likely this is a one off to meet the unique mission requirements that was not fully debugged. Depending on what the failure was, it may, or may not be related to the stack. The stack may be, and most likely is perfectly fine. It may be a failure due to something as simple as the flight computer not handling daylight savings time in the manor they expected. That is what is so frustrating about a failure like this when you can not drag it back to the lab and dissect.
« Last Edit: 11/11/2011 05:28 pm by kevin-rf »
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Offline HammerD

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #784 on: 11/11/2011 05:41 pm »
I know this is not possible now but for situations like these it would have been nice to have the Shuttle to go up and grab it and bring it back home, or to fix it in-place.

Sure the cost doesn't make sense with the Phobos Grunt mission but in principle that functionality was nice to have (eg. Fix Hubble).
« Last Edit: 11/11/2011 05:42 pm by HammerD »

Offline robertross

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #785 on: 11/11/2011 05:44 pm »
I know this is not possible now but for situations like these it would have been nice to have the Shuttle to go up and grab it and bring it back home, or to fix it in-place.

Sure the cost doesn't make sense with the Phobos Grunt mission but in principle that functionality was nice to have (eg. Fix Hubble).

Not possible, especially in regards to limited timeframe. Even in a LON configuration, the crews wouldn't be trained for such tasks. Plus, you really don't want to bring back fully fueled spacecraft if you could help it. What would happen if it started back up again during ops?

Non-starter.

Offline rdale

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #786 on: 11/11/2011 05:45 pm »
I know this is not possible now but for situations like these it would have been nice to have the Shuttle to go up and grab it and bring it back home, or to fix it in-place.

It never was possible, even if the shuttle was around.

Offline Rocket Science

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #787 on: 11/11/2011 05:45 pm »
Difficult finding any news on Russian sites... Blackout? I have this...
http://rt.com/news/phobos-probe-space-mars-037/
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Offline Vladi

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #788 on: 11/11/2011 05:50 pm »
No point in sending a shuttle, the entire probe costs in the region of 160 million dollars including R&D. Making one more should not exceed 50-100 million+launch costs, while a single shuttle flight will cost a lot more.

By the way, extremely interesting article about the probe's control and communication system, however it is in Russian and does not describe the final configuration.
http://www.novosti-kosmonavtiki.ru/phpBB2/viewtopic.php?t=12378

Offline olasek

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #789 on: 11/11/2011 06:07 pm »
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....
« Last Edit: 11/11/2011 06:12 pm by olasek »

Offline Trouquel

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #790 on: 11/11/2011 06:08 pm »
No point in sending a shuttle, the entire probe costs in the region of 160 million dollars including R&D. Making one more should not exceed 50-100 million+launch costs, while a single shuttle flight will cost a lot more.

By the way, extremely interesting article about the probe's control and communication system, however it is in Russian and does not describe the final configuration.
http://www.novosti-kosmonavtiki.ru/phpBB2/viewtopic.php?t=12378

Well, it differs in the number of orbit corrections.
But I hope it is similar in part of communications on LEO at least before the 1st engine burn.

Offline kaptein80

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #791 on: 11/11/2011 06:09 pm »
No point in sending a shuttle, the entire probe costs in the region of 160 million dollars including R&D. Making one more should not exceed 50-100 million+launch costs, while a single shuttle flight will cost a lot more.

some numbers from wikipedia:

shuttle cost: approximately $1.5 billion per launch over the life of the program

Curiosity:  US$2.3 billion

Phobos Grunt: $163 million

NASA/ESA joint Mars sample return mission is expected to cost around $8.5 billion

Offline Blackstar

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #792 on: 11/11/2011 06:16 pm »
some numbers from wikipedia:

shuttle cost: approximately $1.5 billion per launch over the life of the program

Curiosity:  US$2.3 billion

Phobos Grunt: $163 million

NASA/ESA joint Mars sample return mission is expected to cost around $8.5 billion


Such comparisons are essentially meaningless. The economies are not equivalent. Plus, that shuttle cost is an amortized cost, not a single mission marginal cost.

Finally, what good is a cheap mission if it fails?

Offline yamato

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #793 on: 11/11/2011 06:23 pm »
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....

not really, some probes were recycled, like the Stardust, Chang´e was sent to lunar L point after completion of its primary mission...

It depends on the probe construction. Phobos-Grunt has much of dV in its tanks, it would surely get to moon, maybe some asteroid, and its spectrometers would surely provide some valuable results. If they had contact... but they don´t  :(

Offline Ronsmytheiii

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #794 on: 11/11/2011 06:27 pm »
Plus, you really don't want to bring back fully fueled spacecraft if you could help it. What would happen if it started back up again during ops?

Non-starter.

Not necessarily. First of all, you would not have to bring the spacecraft back. Simply find a way to charge the battery or bring up more.  Then you could load a patch right at the spacecraft.  Very similar to the Intelsat/STS-49 mission where the kick stage did not fire, so it was replaced.

Offline kevin-rf

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #795 on: 11/11/2011 06:40 pm »
Plus, you really don't want to bring back fully fueled spacecraft if you could help it. What would happen if it started back up again during ops?

Non-starter.

Not necessarily. First of all, you would not have to bring the spacecraft back. Simply find a way to charge the battery or bring up more.  Then you could load a patch right at the spacecraft.  Very similar to the Intelsat/STS-49 mission where the kick stage did not fire, so it was replaced.

May I remind you of what happened to Arabsat-4M Briz-M. For that reason alone placing lives near a fully loaded upper stage like that is a non-starter! You can not bring the risk to zero!

Correct me if I am wrong but the Intelsat  on STS-49 was a mono-prop system with a solid upper stage. Apples and oranges.
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Offline Chris Bergin

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.
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Offline Ronsmytheiii

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #797 on: 11/11/2011 06:43 pm »
May I remind you of what happened to Arabsat-4M Briz-M. For that reason alone placing lives near a fully loaded upper stage like that is a non-starter! You can not bring the risk to zero!

Correct me if I am wrong but the Intelsat  on STS-49 was a mono-prop system with a solid upper stage. Apples and oranges.

Shuttle was going to launch with a Centaur hydrolox in the payload bay, which would have been much riskier. 

Offline olasek

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #798 on: 11/11/2011 06:48 pm »
Shuttle was going to launch with a Centaur hydrolox in the payload bay, which would have been much riskier. 
But ultimately exactly because it was deemed too risky the plan was scrapped.

Offline JimO

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Re: LIVE: Zenit-2SB launch with Phobos-Grunt - November 8, 2011
« Reply #799 on: 11/11/2011 06:53 pm »
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'?




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