Author Topic: Antares General Discussion Thread  (Read 363169 times)

Offline A12

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Re: Antares General Discussion Thread
« Reply #320 on: 11/05/2014 05:02 pm »
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 ?

Offline Prober

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Re: Antares General Discussion Thread
« Reply #321 on: 11/05/2014 06:56 pm »
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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Offline woods170

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Re: Antares General Discussion Thread
« Reply #322 on: 11/05/2014 07:07 pm »
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.

Offline A12

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Re: Antares General Discussion Thread
« Reply #323 on: 11/05/2014 07:12 pm »
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  ?

Online PahTo

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Re: Antares General Discussion Thread
« Reply #324 on: 11/05/2014 07:12 pm »

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).

Offline arachnitect

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Re: Antares General Discussion Thread
« Reply #325 on: 11/05/2014 07:15 pm »
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?
« Last Edit: 11/05/2014 07:18 pm by arachnitect »

Offline russianhalo117

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Re: Antares General Discussion Thread
« Reply #326 on: 11/05/2014 07:18 pm »
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.

Offline woods170

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Re: Antares General Discussion Thread
« Reply #327 on: 11/05/2014 07:31 pm »
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.
« Last Edit: 11/05/2014 07:34 pm by woods170 »

Offline Pelorat

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Re: Antares General Discussion Thread
« Reply #328 on: 11/05/2014 08:11 pm »
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.
« Last Edit: 11/05/2014 08:14 pm by Pelorat »

Offline russianhalo117

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Re: Antares General Discussion Thread
« Reply #329 on: 11/05/2014 08:59 pm »
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.
« Last Edit: 11/05/2014 09:01 pm by russianhalo117 »

Offline R7

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Re: Antares General Discussion Thread
« Reply #330 on: 11/05/2014 09:34 pm »
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.de

Fuel side:

grey: main shaft
orange: inducer + 1st stage
green: idler wheel
blue: kick stage



Oxidizer side:

green: main shaft
blue: inducer + 1st stage

AD·ASTRA·ASTRORVM·GRATIA

Offline Remes

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Re: Antares General Discussion Thread
« Reply #331 on: 11/05/2014 10:36 pm »
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...)

Offline R7

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Re: Antares General Discussion Thread
« Reply #332 on: 11/05/2014 10:52 pm »
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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Offline Zed_Noir

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Re: Antares General Discussion Thread
« Reply #333 on: 11/06/2014 05:23 am »
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.
 

Offline Remes

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Re: Antares General Discussion Thread
« Reply #334 on: 11/06/2014 08:10 am »
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.

Offline Prober

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Re: Antares General Discussion Thread
« Reply #335 on: 11/06/2014 04:28 pm »
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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Offline woods170

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Re: Antares General Discussion Thread
« Reply #336 on: 11/06/2014 05:16 pm »
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).
« Last Edit: 11/06/2014 05:16 pm by woods170 »

Online matthewkantar

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Re: Antares General Discussion Thread
« Reply #337 on: 11/06/2014 05:28 pm »
Cool video, but I am experiencing some difficulties with the subtitles.

Offline Kabloona

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Re: Antares General Discussion Thread
« Reply #338 on: 11/06/2014 05:31 pm »
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.
« Last Edit: 11/06/2014 05:32 pm by Kabloona »

Offline newpylong

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Re: Antares General Discussion Thread
« Reply #339 on: 11/06/2014 05:55 pm »
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.

 

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