>> What are the chances of the Falcon 9 blowing up too?
> I'd say chances are far better of a successful F9 Heavy launch since > its components are going to be much better tested in the medium version > first.
> But the first Heavy will likely have a substantial pucker factor.
Any triple banger is iffy, especially on the first launch.
Apples and orangutans. The Russians were really pushing the schedule for the N-1 due to the moon race. The Americans were doing the same with Saturn V and were lucky that the incidents they had didn't destroy the vehicle. The Saturn V POGO problems got really close to disaster on at least one flight.
> What are the chances of the Falcon 9 blowing up too?
Depens on how reliable a single engine is, then you can use statistics to figure out the chance of engine failure. Even so, liquid engine failures are usually benign. With nine engines on each core, you simply shut the malfunctioning engine and continue the mission. Luckily for SpaceX, they're not in a race with the Russians and can take their time with testing. ;-)
Jeff -- "Take heart amid the deepening gloom that your dog is finally getting enough cheese" - Deteriorata - National Lampoon
Jeff Findley <jeff.find...@ugs.nojunk.com> wrote: > Luckily for SpaceX, they're not in a race with the Russians and can > take their time with testing. ;-)
Actually, I think they are in an even more difficult race - a race with their funding.
rick jones -- web2.0 n, the dot.com reunion tour... 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...
"Jeff Findley" <jeff.find...@ugs.nojunk.com> writes: >> What are the chances of the Falcon 9 blowing up too?
> Depens on how reliable a single engine is, then you can use statistics to > figure out the chance of engine failure. Even so, liquid engine failures > are usually benign. With nine engines on each core, you simply shut the > malfunctioning engine and continue the mission. Luckily for SpaceX, they're > not in a race with the Russians and can take their time with testing. ;-)
Additionally the Russians did never test the N-1 first stage prior to launch, while SpaceX already did a full test for the F-9 first stage. This is not to say that the Falcon 9 (Heavy) can't fail, but it has a much higher chance not to fail than the N-1.
Jochem
-- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery
In message <m2hbtaw2bu....@revier.com> Jochem Huhmann <j...@gmx.net> wrote:
> "Jeff Findley" <jeff.find...@ugs.nojunk.com> writes: > > >> What are the chances of the Falcon 9 blowing up too? > > > > Depens on how reliable a single engine is, then you can use statistics to > > figure out the chance of engine failure. Even so, liquid engine failures > > are usually benign. With nine engines on each core, you simply shut the > > malfunctioning engine and continue the mission. Luckily for SpaceX, they're > > not in a race with the Russians and can take their time with testing. ;-) > > Additionally the Russians did never test the N-1 first stage prior to > launch, while SpaceX already did a full test for the F-9 first stage.
There's also a considerable difference between feeding 30 engines from a single set of tanks and feeding each group of nine engines from its own set of tanks. The more complex the plumbing, the more potential problems there are.
Anthony Frost <Vu...@vulch.org> wrote: >There's also a considerable difference between feeding 30 engines from >a single set of tanks and feeding each group of nine engines from its >own set of tanks. The more complex the plumbing, the more potential >problems there are.
Not that 3 sets of plumbing each serving 'x' engines is actually less complex than 1 set serving 3'x' engines.
<jeff.find...@ugs.nojunk.com> wrote: >Depens on how reliable a single engine is, then you can use statistics to >figure out the chance of engine failure. Even so, liquid engine failures >are usually benign. With nine engines on each core, you simply shut the >malfunctioning engine and continue the mission.
And hope the wiring didn't get botched between the controllers and all those engines, resulting in a good engine being turned off and the bad one going kablooey.
Brian Thorn <bthor...@suddenlink.net> writes: > On Wed, 4 Nov 2009 11:16:19 -0500, "Jeff Findley" > <jeff.find...@ugs.nojunk.com> wrote:
>>Depens on how reliable a single engine is, then you can use statistics to >>figure out the chance of engine failure. Even so, liquid engine failures >>are usually benign. With nine engines on each core, you simply shut the >>malfunctioning engine and continue the mission.
> And hope the wiring didn't get botched between the controllers and all > those engines, resulting in a good engine being turned off and the bad > one going kablooey.
I'd say there are better strategies available to avoid that than "hope"...
Jochem
-- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery
Jochem Huhmann wrote: > Brian Thorn <bthor...@suddenlink.net> writes:
>> On Wed, 4 Nov 2009 11:16:19 -0500, "Jeff Findley" >> <jeff.find...@ugs.nojunk.com> wrote:
>>> Depens on how reliable a single engine is, then you can use statistics to >>> figure out the chance of engine failure. Even so, liquid engine failures >>> are usually benign. With nine engines on each core, you simply shut the >>> malfunctioning engine and continue the mission. >> And hope the wiring didn't get botched between the controllers and all >> those engines, resulting in a good engine being turned off and the bad >> one going kablooey.
> I'd say there are better strategies available to avoid that than "hope"...
America is on the fast track 'faith' and 'hope' path to failure.
Why are you so intolerant of America's belief system?
> On Wed, 4 Nov 2009 11:16:19 -0500, "Jeff Findley" > <jeff.find...@ugs.nojunk.com> wrote:
>>Depens on how reliable a single engine is, then you can use statistics to >>figure out the chance of engine failure. Even so, liquid engine failures >>are usually benign. With nine engines on each core, you simply shut the >>malfunctioning engine and continue the mission.
> And hope the wiring didn't get botched between the controllers and all > those engines, resulting in a good engine being turned off and the bad > one going kablooey.
That particular Russian failure ought to have been caught during pre-launch testing, but they were in a race to beat the Americans and corners were cut in the name of time. Hopefully SpaceX is more detail oriented than the Russians were during the space race.
Jeff -- "Take heart amid the deepening gloom that your dog is finally getting enough cheese" - Deteriorata - National Lampoon
>>>Depens on how reliable a single engine is, then you can use >>>statistics to figure out the chance of engine failure. Even so, >>>liquid engine failures are usually benign. With nine engines on each >>>core, you simply shut the malfunctioning engine and continue the >>>mission.
>> And hope the wiring didn't get botched between the controllers and >> all those engines, resulting in a good engine being turned off and >> the bad one going kablooey.
> That particular Russian failure ought to have been caught during > pre-launch testing, but they were in a race to beat the Americans and > corners were cut in the name of time. Hopefully SpaceX is more detail > oriented than the Russians were during the space race.
Hasn't that scenario already been tested on the ground with Falcon 9? Engines will normally be shut down near the end of the first stage burn to limit acceleration and shutdown transients.
I'd like to think communications between the flight controller and individual engine controllers will more sophisticated than the N-1 apparently was.
>>>>Depens on how reliable a single engine is, then you can use >>>>statistics to figure out the chance of engine failure. Even so, >>>>liquid engine failures are usually benign. With nine engines on each >>>>core, you simply shut the malfunctioning engine and continue the >>>>mission.
>>> And hope the wiring didn't get botched between the controllers and >>> all those engines, resulting in a good engine being turned off and >>> the bad one going kablooey.
>> That particular Russian failure ought to have been caught during >> pre-launch testing, but they were in a race to beat the Americans and >> corners were cut in the name of time. Hopefully SpaceX is more detail >> oriented than the Russians were during the space race.
> Hasn't that scenario already been tested on the ground with Falcon 9? > Engines will normally be shut down near the end of the first stage > burn to limit acceleration and shutdown transients.
> I'd like to think communications between the flight controller and > individual engine controllers will more sophisticated than the N-1 > apparently was.
I don't think the "sophistication" of an engine controller matters if the guys assembling the rocket stage don't plug the right connectors into the right sockets. Getting your "wires crossed" in this manner can have disastrous consequences, so you would want to run tests on the ground before you launch the thing.
Jeff -- "Take heart amid the deepening gloom that your dog is finally getting enough cheese" - Deteriorata - National Lampoon
>>>Depens on how reliable a single engine is, then you can use statistics to >>>figure out the chance of engine failure. Even so, liquid engine failures >>>are usually benign. With nine engines on each core, you simply shut the >>>malfunctioning engine and continue the mission.
>> And hope the wiring didn't get botched between the controllers and all >> those engines, resulting in a good engine being turned off and the bad >> one going kablooey.
>That particular Russian failure ought to have been caught during pre-launch >testing, but they were in a race to beat the Americans and corners were cut >in the name of time. Hopefully SpaceX is more detail oriented than the >Russians were during the space race.
Yet, the detail oriented Americans made an equally significant wiring error on AS-502.
> "Jeff Findley" <jeff.find...@ugs.nojunk.com> wrote: > :I don't think the "sophistication" of an engine controller matters if the > :guys assembling the rocket stage don't plug the right connectors into the > :right sockets. Getting your "wires crossed" in this manner can have > :disastrous consequences, so you would want to run tests on the ground > before > :you launch the thing. > :
> What if they don't connect the brake lines on your car to the right > things?
That doesn't seem to directly relate to complex wiring harnesses on expendable vehicles which are hand built due to very low production rates.
> What if the flight controls on that jetliner you're riding > are reversed?
Every time I've flown with a pilot friend of mine, he runs through a pre-flight check which would catch this problem. Neglecting to perform basic pre-flight checks is especially foolish when you've never flown that particular aircraft before (which is the case for every launch of an expendable vehicle).
> Some things are just preposterous to worry about.
Hope is not a satisfactory substitute for a quality assurance program.
Jeff -- "Take heart amid the deepening gloom that your dog is finally getting enough cheese" - Deteriorata - National Lampoon
>>>>Depens on how reliable a single engine is, then you can use statistics >>>>to >>>>figure out the chance of engine failure. Even so, liquid engine >>>>failures >>>>are usually benign. With nine engines on each core, you simply shut the >>>>malfunctioning engine and continue the mission.
>>> And hope the wiring didn't get botched between the controllers and all >>> those engines, resulting in a good engine being turned off and the bad >>> one going kablooey.
>>That particular Russian failure ought to have been caught during >>pre-launch >>testing, but they were in a race to beat the Americans and corners were >>cut >>in the name of time. Hopefully SpaceX is more detail oriented than the >>Russians were during the space race.
> Yet, the detail oriented Americans made an equally significant wiring > error on AS-502.
True, and hopefully you learn from such early failures (this was only the second, unmanned, flight test of the Saturn V).
Hand wired expendable launch vehicles such as these really ought to be better tested before they're flown. Unfortunately, there are some things that you simply can't test without flying. Every flight is the first flight for an expendable, so infant mortality problems such as these become especially troublesome.
Jeff -- "Take heart amid the deepening gloom that your dog is finally getting enough cheese" - Deteriorata - National Lampoon
<jeff.find...@ugs.nojunk.com> wrote: >> And hope the wiring didn't get botched between the controllers and all >> those engines, resulting in a good engine being turned off and the bad >> one going kablooey.
>That particular Russian failure ought to have been caught during pre-launch >testing, but they were in a race to beat the Americans and corners were cut >in the name of time. Hopefully SpaceX is more detail oriented than the >Russians were during the space race.
It almost happened to Saturn V AS-502 also, the bad engine shut down on its own, fortunately. And Martin-Marietta botched the wiring on Commercial Titan III because they got the single payload/dual payload setup reversed.
> Additionally the Russians did never test the N-1 first stage prior to > launch, while SpaceX already did a full test for the F-9 first stage. > This is not to say that the Falcon 9 (Heavy) can't fail, but it has a > much higher chance not to fail than the N-1.
All four N=1 failures were due to different causes, not some fundamental flaw in the engines.
> There's also a considerable difference between feeding 30 engines from > a single set of tanks and feeding each group of nine engines from its > own set of tanks. The more complex the plumbing, the more potential > problems there are.
N-1 plumbing was a complex and heavy mess with so many long pipes being involved that it was almost begging for some pipe or weld seam to fail under launch vibration.
Jeff Findley wrote: >> And hope the wiring didn't get botched between the controllers and all >> those engines, resulting in a good engine being turned off and the bad >> one going kablooey.
> That particular Russian failure ought to have been caught during pre-launch > testing, but they were in a race to beat the Americans and corners were cut > in the name of time. Hopefully SpaceX is more detail oriented than the > Russians were during the space race.
> It almost happened to Saturn V AS-502 also, the bad engine shut down > on its own, fortunately. And Martin-Marietta botched the wiring on > Commercial Titan III because they got the single payload/dual payload > setup reversed.
Ariane V failed during its first launch when the guidance system reverted into a ground test configuration during flight.
Pat Flannery <flan...@daktel.com> writes: > Jochem Huhmann wrote:
>> Additionally the Russians did never test the N-1 first stage prior to >> launch, while SpaceX already did a full test for the F-9 first stage. >> This is not to say that the Falcon 9 (Heavy) can't fail, but it has a >> much higher chance not to fail than the N-1.
> All four N=1 failures were due to different causes, not some fundamental > flaw in the engines.
But all were due to a flaw in the first stage which could have been caught with full testing. They did never (to my knowlegde) a full vibration test, a fuel flow test or (god forbid) a test with all engines running for the full duration of the first stage burn.
All of that has been done with the Falcon 9 first stage, though. All engines running with a full first stage attached for the full duration of a real launch. This still leaves the aerodynamic effects out, but I would say that there's about an order of magnitude more confidence in the thing than in the N-1 now.
Jochem
-- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery
On Tue, 10 Nov 2009 00:38:45 +0100, Jochem Huhmann <j...@gmx.net> wrote:
>But all were due to a flaw in the first stage which could have been >caught with full testing. They did never (to my knowlegde) a full >vibration test, a fuel flow test or (god forbid) a test with all engines >running for the full duration of the first stage burn.
...Correct. About the only static testing they did was individual engines, and possibly 2-3 engines in cluster. The issue was secrecy, in that either a static test of the full 30+ engine cluster and/or a single-stage launch test could/would have been detected by US spy sats - which is what happened anyway when they rolled the full stack out to the launch site either the first or second time, there's some debate about which pad checkout was caught and labled as "TT-5".
OM -- ]=====================================[ ] OMBlog - http://www.io.com/~o_m/omworld [ ] Let's face it: Sometimes you *need* [ ] an obnoxious opinion in your day! [ ]=====================================[
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