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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
It would seem that the most recent Falcon 9 launch included an
unplanned test of its engine-out capability: http://www.theregister.co.uk/2012/10...alco_flameout/ rick jones -- the road to hell is paved with business decisions... these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
#2
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
Rick Jones wrote:
It would seem that the most recent Falcon 9 launch included an unplanned test of its engine-out capability: http://www.theregister.co.uk/2012/10...alco_flameout/ And it would seem that a secondary payload isn't quite where it was meant to be: http://cosmiclog.nbcnews.com/_news/2...goes-awry?lite rick jones -- portable adj, code that compiles under more than one compiler these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
#3
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
In article ,
says... Rick Jones wrote: It would seem that the most recent Falcon 9 launch included an unplanned test of its engine-out capability: http://www.theregister.co.uk/2012/10...alco_flameout/ And it would seem that a secondary payload isn't quite where it was meant to be: http://cosmiclog.nbcnews.com/_news/2...goes-awry?lite From what I read today, this is looking more and more like a complete failure for the secondary payload. http://www.nasaspaceflight.com/2012/...review-falcon- 9-ascent-issues/ From above, it looks like the plan was to have the second stage do a burn after Dragon separation. However, the second stage didn't pass a propellant mass check required by NASA to insure that the satellite would be inserted into an orbit that would guarantee no risk of collision with ISS. The backup plan to release the satellite in the second stage's parking orbit was executed. Because of this, none of the remaining second stage propellant could be used to help move the satellite into a more favorable orbit. I wonder what the final orbit for the secondary payload would have been if Falcon 9's second stage would have been allowed to perform a final burn to fuel/oxidizer depletion. Jeff -- "the perennial claim that hypersonic airbreathing propulsion would magically make space launch cheaper is nonsense -- LOX is much cheaper than advanced airbreathing engines, and so are the tanks to put it in and the extra thrust to carry it." - Henry Spencer |
#4
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
Jeff Findley wrote:
From what I read today, this is looking more and more like a complete failure for the secondary payload. http://www.nasaspaceflight.com/2012/...review-falcon- 9-ascent-issues/ From above, it looks like the plan was to have the second stage do a burn after Dragon separation. However, the second stage didn't pass a propellant mass check required by NASA to insure that the satellite would be inserted into an orbit that would guarantee no risk of collision with ISS. The backup plan to release the satellite in the second stage's parking orbit was executed. Because of this, none of the remaining second stage propellant could be used to help move the satellite into a more favorable orbit. I wonder what the final orbit for the secondary payload would have been if Falcon 9's second stage would have been allowed to perform a final burn to fuel/oxidizer depletion. How long can the second stage "wait" before performing a second (and I presume final?) burn? Also, I'm still trying to come to grips with what apart from an "according to common usage among the peanut gallery" "explosion" would have caused those pressure relieving panels to blow. "Engine pressure release" sounds a bit like describing a fire as an "exothermal event with external charring." I think it was a great demonstration of the Falcon9's resiliance but euphamisms (assuming they are indeed getting used here) don't speak well towards organizational resiliance. Or perhaps it is just my peanut-gallery understanding of terminology. rick jones -- Process shall set you free from the need for rational thought. these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
#6
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
Jeff Findley wrote:
In article , says... How long can the second stage "wait" before performing a second (and I presume final?) burn? Speculation on ARocket is that the burn was canceled more because of the NASA imposed rules to prevent anything from hitting ISS. Supposedly this off-nominal situation was so far off nominal that it wasn't covered by the analyses done for this reason. Because of this, they had to go to the backup plan. So the second stage of the rocket system that has a first stage which can supposedly "complete the mission" if it loses two engines, ended-up without enough propellant to complete the mission? Or is the second stage's lack of sufficent fuel/oxidizer for the burn not a result of the first stage's loss of an engine? rick jones -- No need to believe in either side, or any side. There is no cause. There's only yourself. The belief is in your own precision. - Joubert these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
#7
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
Rick Jones used his keyboard to write :
So the second stage of the rocket system that has a first stage which can supposedly "complete the mission" if it loses two engines, ended-up without enough propellant to complete the mission? Where did you get this from Jeff's posting? Upthread, he notes there was fuel available, but that it wasn't used because off possible conflict with ISS trsjectories. /dps -- Who, me? And what lacuna? |
#8
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
Snidely wrote:
Rick Jones used his keyboard to write : So the second stage of the rocket system that has a first stage which can supposedly "complete the mission" if it loses two engines, ended-up without enough propellant to complete the mission? Where did you get this from Jeff's posting? Upthread, he notes there was fuel available, but that it wasn't used because off possible conflict with ISS trsjectories. I thought that I'd seen a mention of insufficient fuel somewhere (not necessarily in this newsgroup), but could be mistaken. rick jones -- A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail? |
#9
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
Rick Jones wrote:
I thought that I'd seen a mention of insufficient fuel somewhere (not necessarily in this newsgroup), but could be mistaken. I think I got the impression from http://news.cnet.com/8301-11386_3-57...ngine-failure/ though reading it again shows I may have read too much into that. So, *did* the second stage have to burn longer on its first burn as part of compensating for the loss of the first-stage engine? If the second stage were where it was nominally supposed to be after the first burn, with the nominally expected quantity of fuel and oxidizer etc remaining, presumably it should have been in a state where the second burn could be permitted. But the second burn was not permitted, so doesn't that suggest that either the second stage was not where it was nominally supposed to be, and/or didn't have the nomninal quantity of remaining fuel/oxidizer? If so, was that then a consequence of having to compensate for the first-stage engine-out (goes to "Falcon 9 can complete the mission with a first-stage engine-out"), or was there an additional problem, involving the second stage more directly? rick jones -- No need to believe in either side, or any side. There is no cause. There's only yourself. The belief is in your own precision. - Joubert these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
#10
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Unplanned engine-out resiliance test for CRS-1 Falcon 9?
In article ,
says... Jeff Findley wrote: In article , says... How long can the second stage "wait" before performing a second (and I presume final?) burn? Speculation on ARocket is that the burn was canceled more because of the NASA imposed rules to prevent anything from hitting ISS. Supposedly this off-nominal situation was so far off nominal that it wasn't covered by the analyses done for this reason. Because of this, they had to go to the backup plan. So the second stage of the rocket system that has a first stage which can supposedly "complete the mission" if it loses two engines, ended-up without enough propellant to complete the mission? Or is the second stage's lack of sufficent fuel/oxidizer for the burn not a result of the first stage's loss of an engine? The Falcon 9 first stage has nine engines (hence the origins of its name). One first stage engine failed in a somewhat spectacular way. To compensate, the first stage burned longer, but due to the lower thrust of the first stage, it surely incurred more drag and gravity losses than on a nominal launch. Because of the first stage losses, the second stage must have also burned longer in order to make it into the proper "parking" orbit for Dragon release. So, the launch was a success for Dragon. The second stage only has one engine, so burning longer left it with less fuel than a nominal mission. This meant that there wasn't enough fuel for the next burn. This burn would have placed the secondary payload into its final orbit. This was at least a partial failure for the secondary payload any way you look at it. Unfortunately, because of the ISS constraint, SpaceX wasn't allowed to perform any additional burn using the fuel remaining in the second stage. So, the backup plan was initiated which released the secondary payload into the parking orbit, which is a far cry from its intended orbit. If it weren't for the ISS constraint, SpaceX surely would have done the second burn (likely to fuel depletion) in order to place the secondary payload into as favorable of an orbit as they could. But they couldn't, which is a shame for the secondary payload. The bottom line is that this was a successful launch of the primary payload (Dragon), but a nearly complete failed launch for the secondary payload. Sucks to be a secondary payload when "stuff happens". Jeff -- "the perennial claim that hypersonic airbreathing propulsion would magically make space launch cheaper is nonsense -- LOX is much cheaper than advanced airbreathing engines, and so are the tanks to put it in and the extra thrust to carry it." - Henry Spencer |
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