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#320
by
A12
on 05 Nov, 2014 17:02
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What is not clear to me is in which way the first eight engines worked flawlessly and only now the NK-33 became untrustworthy.
Is it possible that they did select the best eight engines for the earlier launches ?
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#321
by
Prober
on 05 Nov, 2014 18:56
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What is not clear to me is in which way the first eight engines worked flawlessly and only now the NK-33 became untrustworthy.
Is it possible that they did select the best eight engines for the earlier launches ?
think your reading it wrong; its more of a schedule issue
1) Mars pad needs to be rebuilt
2) Orbital tried many times to obtain newly manufactured Kuznetzov engines for long term launches. When the finite supply of AJ-26's runs out Antares is out of the launch business.
3) Orbital could rebuild Mars and finish out the AJ-26's. But in a short time Antares & Mars would both need to be rebuilt. Best to take advantage of the downtime and do this one time not two.
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#322
by
woods170
on 05 Nov, 2014 19:07
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What is not clear to me is in which way the first eight engines worked flawlessly and only now the NK-33 became untrustworthy.
Pardon me? Teststand failures of AJ-26's in 2011 and 2014. That does not sound like a reliable - let alone trustworthy - engine.
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#323
by
A12
on 05 Nov, 2014 19:12
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What is not clear to me is in which way the first eight engines worked flawlessly and only now the NK-33 became untrustworthy.
Pardon me? Teststand failures of AJ-26's in 2011 and 2014. That does not sound like a reliable - let alone trustworthy - engine.
And so, they was just tempting fate launching again with the same not so reliable engine ?
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#324
by
PahTo
on 05 Nov, 2014 19:12
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Cross-posting from the failure argument--er, I mean thread.
This is probably a better place for it anyway...
btw, nobody has bothered to mention the implications for ATK (ORB/ATK) in that the Castor 30XL is now a second stage without a passenger, at least for the next few years. How many have been produced (if any) and will they be certified for the "new" Antares LV after being stored for x years? (I assume they will be used in conjunction with the "new" Antares).
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#325
by
arachnitect
on 05 Nov, 2014 19:15
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What is not clear to me is in which way the first eight engines worked flawlessly and only now the NK-33 became untrustworthy.
Pardon me? Teststand failures of AJ-26's in 2011 and 2014. That does not sound like a reliable - let alone trustworthy - engine.
It is possible that they were hand picking engines and the "best" ones went first. I guess the exact number of engines in stockpile was never precisely defined partly because as the program went on it started to become clear not all of them could be flight worthy.
This was the heaviest Antares yet to launch, but I doubt that contributed.
Cross-posting from the failure argument--er, I mean thread. This is probably a better place for it anyway...
btw, nobody has bothered to mention the implications for ATK (ORB/ATK) in that the Castor 30XL is now a second stage without a passenger, at least for the next few years. How many have been produced (if any) and will they be certified for the "new" Antares LV after being stored for x years? (I assume they will be used in conjunction with the "new" Antares).
I don't really know but I doubt it would be a huge problem for a few motors to sit around until 2016 or so. How old are the Peacekeeper motors that end up in Minotaur rockets?
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#326
by
russianhalo117
on 05 Nov, 2014 19:18
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Assuming (and that is all it is so far) that the ORB-CRS-3 anomaly is ultimately due to an engine failure this gives NK-33 a failure rate of 1-in-4, as of now, including the two test stand failures. Am I correct?
(Asked not to bash but because I genuinely want the information)
You should take then failures/firings. That should include the flown engines test stages. And each Antares fly 2 engines. So it was a 1-in-8 failure in flight, plus at least 2-in-10 in test stand.
there were 5 NK-33 tests at Stennis in 1995/96. other than that for AJ-26.62 version you are correct. Overall NK-33 test programme for Soyuz-2.1v has also had three ground test failures since 2003 with two caused by turbopump/line contamination due to age and one destroyed Soyuz Core stage ground firing article due to overpressure of the enigine feed to sterring engines and failure to abort.
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#327
by
woods170
on 05 Nov, 2014 19:31
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What is not clear to me is in which way the first eight engines worked flawlessly and only now the NK-33 became untrustworthy.
Pardon me? Teststand failures of AJ-26's in 2011 and 2014. That does not sound like a reliable - let alone trustworthy - engine.
And so, they was just tempting fate launching again with the same not so reliable engine ?
IMO yes.
Lesson to be learned from all this: don't use 40 year old hardware that spent the first 20 years in storage in less-than-ideal conditions. You basically don't know what happened to the hardware for a very substantial amount of time.
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#328
by
Pelorat
on 05 Nov, 2014 20:11
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Would this be the turbo pump in question?
Seems to be quite a complex beast, definitely not a KISS design to the armchair engineer inside of me. But if you take into account that this thing was designed and built at the peak of the space race many decades ago, it really comes across as quite an accomplishment.
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#329
by
russianhalo117
on 05 Nov, 2014 20:59
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Would this be the turbo pump in question?
Seems to be quite a complex beast, definitely not a KISS design to the armchair engineer inside of me. But if you take into account that this thing was designed and built at the peak of the space race many decades ago, it really comes across as quite an accomplishment.
That looks like it to me. NK-33 uses a unified turbpump shaft for both fuel and oxidizer. Not sure if this is of the original NK-33 series or the new turbopump developed for NK-33A.
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#330
by
R7
on 05 Nov, 2014 21:34
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Seems to be quite a complex beast
It is, and the video does not clearly illustrate the whole complexity. Fuel and oxidizer inducers (the distinctive large screws) are on hollow shafts and run at slower speeds than coaxial main shaft. Fuel inducer is geared down while another gear makes small fuel kick impeller rotate faster than main shaft. The oxidizer inducer can rotate freely and is driven by hydraulic turbine.
See more info on LPRE.deFuel side:
grey: main shaft
orange: inducer + 1st stage
green: idler wheel
blue: kick stage
Oxidizer side:
green: main shaft
blue: inducer + 1st stage
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#331
by
Remes
on 05 Nov, 2014 22:36
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Seems to be quite a complex beast, definitely not a KISS design
I don't think that there is much which could be made simpler nowadays. The NK-33 turbopump integrates fuel+oxidizer pump, fuel+oxidizer pre-pump, preburner, turbine, Fuel-boost pump and starter cartridge/turbine into one assembly. That are really a lot of functions. Very compact.
Really amazing, what was created back then. Without cfd, fem and cad. (Okay, they didn't have to fight powerpoint-heros...)
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#332
by
R7
on 05 Nov, 2014 22:52
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I don't think that there is much which could be made simpler nowadays.
It was made simpler back in 70s/early 80s: RD-170 and descendants. Reduced five shafts to three shafts and omitted all gearing.
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#333
by
Zed_Noir
on 06 Nov, 2014 05:23
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Might this be the end of the line for the Antares in any configuration?
If the interim launcher (my guess is Falcon 9) is cheaper than the re-engine Antares, not even factoring in development cost. Might OSC just farm out the launch service to SpaceX (or LM) and just be a mission integrator. That also means shutting down facilities for the procurement of the Antares . Which would boost the bottom line in a cold-blooded corporate manner.
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#334
by
Remes
on 06 Nov, 2014 08:10
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I don't think that there is much which could be made simpler nowadays.
It was made simpler back in 70s/early 80s: RD-170 and descendants. Reduced five shafts to three shafts and omitted all gearing.
how do we count?
NK-33:
- 2 piece rotor
- 2 Impeller
- Fuel Boost Pump shaft
RD-170
- 2 piece rotor
- 2 external prepumps (still shafts) driven by oxygen rich gas and fuel
The fuelpump is now a two-stage pump and doesn't require gearing. The pre-pumps are driven by fluids and don't require gearing, but require piping and turbines.
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#335
by
Prober
on 06 Nov, 2014 16:28
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Well someone is not treating the hardware like 45 year old junk as many in the press are reporting. Looks like training in this recent video.
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#336
by
woods170
on 06 Nov, 2014 17:16
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Well someone is not treating the hardware like 45 year old junk as many in the press are reporting. Looks like training in this recent video.
<snip video, you can view it above>
They may not be treating it as 45 year old junk, but fact is that this stuff is four decades old. And the first half of those four decades the stuff was not treated at all (including TLC).
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#337
by
matthewkantar
on 06 Nov, 2014 17:28
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Cool video, but I am experiencing some difficulties with the subtitles.
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#338
by
Kabloona
on 06 Nov, 2014 17:31
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Might this be the end of the line for the Antares in any configuration?
If the interim launcher (my guess is Falcon 9) is cheaper than the re-engine Antares, not even factoring in development cost. Might OSC just farm out the launch service to SpaceX (or LM) and just be a mission integrator. That also means shutting down facilities for the procurement of the Antares . Which would boost the bottom line in a cold-blooded corporate manner.
I find that doubtful. Orbital has huge investment in Antares development. And they want to be able to launch their own birds. Plus Wallops pad was built specifically for Antares. Antares is a key long-range part of their business plan that they will not pull the plug on, IMO.
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#339
by
newpylong
on 06 Nov, 2014 17:55
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Might this be the end of the line for the Antares in any configuration?
If the interim launcher (my guess is Falcon 9) is cheaper than the re-engine Antares, not even factoring in development cost. Might OSC just farm out the launch service to SpaceX (or LM) and just be a mission integrator. That also means shutting down facilities for the procurement of the Antares . Which would boost the bottom line in a cold-blooded corporate manner.
No.
This is probably a better place for it anyway...