Author Topic: Orbital's Antares Discussion Thread (to Hotfire Test and debut flight)  (Read 35567 times)

Offline Phyto

  • Member
  • Posts: 29
  • Emerald Colombia Australian Gemmologist 5/93 p182
  • Virginia @PhytoPhotonics
    • Your Fluorescence Spectra Source
  • Liked: 2
  • Likes Given: 2

Since both of ULA's rockets (Atlas V and Delta IV) have had good success with ex- & rebuilt Russian/Soviet engines.

Which engine on Delta IV is Russian/Soviet?  And which is one on Atlas is rebuilt?
Boy, now I've got to go do some more (re)search. (Edit) Maybe I'm confusing the common 2nd stage for linking the two; an Atlas V launch having been delayed due to a problem with a Delta IV launch. (end Edit) I'll get back to you with the answer  :-\ , or stand corrected  :-[ .
(2nd Edit)
Phew! that wasn't so hard. Please check: http://www.nasa.gov/pdf/427652main_PMC_2010_Pech_Russian.pdf
Russian RD-180 Rocket Engine for Atlas V Launch Vehicle - Slide date: 10 Feb 2010

So, it looks like I was wrong about the rebuilt part.  So much info, so little time. . .
I know, excuses, excuses.
« Last Edit: 02/14/2013 07:06 PM by Phyto »

Offline Lars_J

  • Senior Member
  • *****
  • Posts: 6161
  • California
  • Liked: 665
  • Likes Given: 195
I can only assume that Orbital is not telling us all the details, because it seems odd that a helium purge level (?) issue would lead to a two week delay until the next hotfire attempt. Or am I missing something?

Online ugordan

  • Senior Member
  • *****
  • Posts: 7532
    • My mainly Cassini image gallery
  • Liked: 1749
  • Likes Given: 386
I can only assume that Orbital is not telling us all the details, because it seems odd that a helium purge level (?) issue would lead to a two week delay until the next hotfire attempt. Or am I missing something?

Why should they tell us all the details?

Offline Lars_J

  • Senior Member
  • *****
  • Posts: 6161
  • California
  • Liked: 665
  • Likes Given: 195
I'm not saying they should. Just noting the apparent discrepancy between the problem and the fix time.

Online ugordan

  • Senior Member
  • *****
  • Posts: 7532
    • My mainly Cassini image gallery
  • Liked: 1749
  • Likes Given: 386
How long would you expect a "helium purge level" or nitrogen purge as actually mentioned in the release should take to fix? Neither of us has the slightest idea on what, specifically, went wrong so neither of us should assume a given turnaround time is too long.

Offline yg1968

  • Senior Member
  • *****
  • Posts: 9679
  • Liked: 1399
  • Likes Given: 877
Quote from: Chris Bergin
Should the next hot fire attempt prove to be successful, the first stage test article will be returned to the Horizontal Integration Facility where the core and two engines will be refurbished for a later flight.

Sorry if this is a dumb question but the engines need to be refurbished after a hot fire test? How long does that take? Is it extensive work?

« Last Edit: 02/14/2013 07:54 PM by yg1968 »

Offline Lurker Steve

  • Full Member
  • ****
  • Posts: 1420
  • Liked: 35
  • Likes Given: 9
How long would you expect a "helium purge level" or nitrogen purge as actually mentioned in the release should take to fix? Neither of us has the slightest idea on what, specifically, went wrong so neither of us should assume a given turnaround time is too long.

Right, when the computers shutdown the SpaceX hot fire test due to some parameter being out of range, SpaceX just changed the ranges on that parameter instead of determining why it was out of range.

Orbital is trying to learn about the performance of their rocket, and are taking their time to investigate all of the issues.

Offline PreferToLurk

  • Full Member
  • ***
  • Posts: 310
  • Liked: 144
  • Likes Given: 23
How long would you expect a "helium purge level" or nitrogen purge as actually mentioned in the release should take to fix? Neither of us has the slightest idea on what, specifically, went wrong so neither of us should assume a given turnaround time is too long.

Right, when the computers shutdown the SpaceX hot fire test due to some parameter being out of range, SpaceX just changed the ranges on that parameter instead of determining why it was out of range.

Orbital is trying to learn about the performance of their rocket, and are taking their time to investigate all of the issues.

That comparison is not fair, the problem with the Spacex hotfire was not the value, but an incorrectly set range.  In such a case fixing the range is proper, and also happens to be easy to do.  There has been no indication that Orbital's problem was simply a bad range. 

Offline kevin-rf

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8652
  • Overlooking the path Mary's little Lamb took..
  • Liked: 1123
  • Likes Given: 243
Just because they identified the cause does not mean the fix is easy. For all we know it might indicate that the purge system is not able to deliver enough N2 for purging. Instead of a software tweak, it may require new plumbing, which will take time.

Orbital has been doing this for a long time, if they say it will take a week to get all the ducks in a row, then Antonioe will have all his ducks in a row before they try again. They decided to not fix it on the fly and try again.

Though I do suspect the Antares could be used to make a mean Peking Duck!
If you're happy and you know it,
It's your med's!

Offline LouScheffer

  • Full Member
  • ****
  • Posts: 1880
  • Liked: 2456
  • Likes Given: 273
For all we know it might indicate that the purge system is not able to deliver enough N2 for purging. Instead of a software tweak, it may require new plumbing, which will take time.

Not enough N2 would be very odd - I can't believe they would try this for the very first time with 1.5 seconds to go in the countdown - surely they tested the purge before.  I'd suspect some sort of interaction, perhaps with cold/ice from the oxidizer, though this is just a wild guess.

Offline Antares

  • ABO^2
  • Senior Member
  • *****
  • Posts: 5201
  • Done arguing with amateurs
  • Liked: 368
  • Likes Given: 226
Orbital has been doing this for a long time, if they say it will take a week to get all the ducks in a row

Orbital has been doing cryo engines that need purge for a long time?  This was the first attempt at starting a liquid engine at an Orbital launch site.  I could see a couple more of these aborts before it's successful.
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline russianhalo117

  • Senior Member
  • *****
  • Posts: 4688
  • AR USA / Berlin, DE / Moscow, RF
  • Liked: 1186
  • Likes Given: 594
Just because they identified the cause does not mean the fix is easy. For all we know it might indicate that the purge system is not able to deliver enough N2 for purging. Instead of a software tweak, it may require new plumbing, which will take time.

Orbital has been doing this for a long time, if they say it will take a week to get all the ducks in a row, then Antonioe will have all his ducks in a row before they try again. They decided to not fix it on the fly and try again.

Though I do suspect the Antares could be used to make a mean Peking Duck!
The purge system worked nominally during the cold flow fluids testing series. So may be something else. AFAIK, GN2 purge system used on AJ-26.62 engines is actually the original NK-33 Heritage GN2 system and so at least on the engine side it dates back a few decades. Outside of the engine all GN2 is new design.
« Last Edit: 02/15/2013 03:19 PM by russianhalo117 »

Offline KSC Sage

  • Member
  • Full Member
  • ***
  • Posts: 347
  • Liked: 487
  • Likes Given: 9
I'm not saying they should. Just noting the apparent discrepancy between the problem and the fix time.

They need to totally understand what the problem was and make sure there is nothing more.  They're retesting the valve and plan the next hotfire test NET next Thursday.

Offline cordor

  • Full Member
  • *
  • Posts: 167
  • Liked: 0
  • Likes Given: 0

Since both of ULA's rockets (Atlas V and Delta IV) have had good success with ex- & rebuilt Russian/Soviet engines.

Which engine on Delta IV is Russian/Soviet?  And which is one on Atlas is rebuilt?
Boy, now I've got to go do some more (re)search. (Edit) Maybe I'm confusing the common 2nd stage for linking the two; an Atlas V launch having been delayed due to a problem with a Delta IV launch. (end Edit) I'll get back to you with the answer  :-\ , or stand corrected  :-[ .
(2nd Edit)
Phew! that wasn't so hard. Please check: http://www.nasa.gov/pdf/427652main_PMC_2010_Pech_Russian.pdf
Russian RD-180 Rocket Engine for Atlas V Launch Vehicle - Slide date: 10 Feb 2010

So, it looks like I was wrong about the rebuilt part.  So much info, so little time. . .
I know, excuses, excuses.

yup, that's RD-180 on Atlas V, Delta IV doesn't use any russian engine. NK family is cursed, N1 was a disaster. Rpk tried to use it and went bankruptcy. Antrares got delayed, how many time exactly?

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32411
  • Cape Canaveral Spaceport
  • Liked: 11149
  • Likes Given: 331
NK family is cursed,

Can't say that.  Antares delays are minor.

Offline russianhalo117

  • Senior Member
  • *****
  • Posts: 4688
  • AR USA / Berlin, DE / Moscow, RF
  • Liked: 1186
  • Likes Given: 594

Since both of ULA's rockets (Atlas V and Delta IV) have had good success with ex- & rebuilt Russian/Soviet engines.

Which engine on Delta IV is Russian/Soviet?  And which is one on Atlas is rebuilt?
Boy, now I've got to go do some more (re)search. (Edit) Maybe I'm confusing the common 2nd stage for linking the two; an Atlas V launch having been delayed due to a problem with a Delta IV launch. (end Edit) I'll get back to you with the answer  :-\ , or stand corrected  :-[ .
(2nd Edit)
Phew! that wasn't so hard. Please check: http://www.nasa.gov/pdf/427652main_PMC_2010_Pech_Russian.pdf
Russian RD-180 Rocket Engine for Atlas V Launch Vehicle - Slide date: 10 Feb 2010

So, it looks like I was wrong about the rebuilt part.  So much info, so little time. . .
I know, excuses, excuses.

yup, that's RD-180 on Atlas V, Delta IV doesn't use any russian engine. NK family is cursed, N1 was a disaster. Rpk tried to use it and went bankruptcy. Antrares got delayed, how many time exactly?
N1 launchers using NK-15 engines were underpowered and NK-15 served as developmental test engine for unflown but more powerful NK-33. NK-33 is a major improvement in terms of design and capability. Yes, its is unflown, but it has continuously proved over decades of testing its overall reliability and performances. The portion of the GN2 Purge system at issue here is not believed to involve the engine itself, but rather portion of the GN2 purge system that ends up connecting to the engine GN2 flow which is the stage one aft compartment GN2 Lines and the interface connecting that stage to its ground-side GN2 GSE. ATM they are trying to figure out where in the GN2 system the off-nominal lack of high pressure occurred when stage one aft compartment and engine final purge was commanded to execute.

Offline cordor

  • Full Member
  • *
  • Posts: 167
  • Liked: 0
  • Likes Given: 0
if i remember correctly, Antares supposed to make first flight last summer, spacex rushed to launch f9 on feb. As soon as osc announced delay to winter, spacex rescheduled f9 to april/may. And then Antares had another delay to this year, and then delay to march.

Im not saying NK is bad engines, they just cause bad luck to whoever use it. call me superstition, hey nasa still pass peanuts every space launch.

Offline sdsds

  • Senior Member
  • *****
  • Posts: 5479
  • "With peace and hope for all mankind."
  • Seattle
  • Liked: 580
  • Likes Given: 677
NK-33 engines may be finicky, and that may make them tricky to integrate into a vehicle. Although Orbital doesn't have much experience with big liquid engines they have lots of general skillz in dealing with tricky integration issues. They're using those to make sure that when the NK-33 engines on this test unit light up, they behave exactly as expected. If anyone can break the "curse" of a finicky engine design, I'm betting it's Orbital!
-- sdsds --

Offline pippin

  • Regular
  • Senior Member
  • *****
  • Posts: 2561
  • Liked: 290
  • Likes Given: 39
Antrares got delayed, how many time exactly?

If delays are a curse, what does this mean for SpaceX? What was the factor between "SpaceX time" and "real time"? 2.5?
And yet they do fly and even somewhat reliably right now (although still always late)

No, delays for a new launcher are simply normal business.
« Last Edit: 02/17/2013 03:52 AM by pippin »

Offline kch

  • Full Member
  • ****
  • Posts: 1764
  • Liked: 492
  • Likes Given: 8815

call me superstition, hey nasa still pass peanuts every space launch.

Somebody should tell them -- it's bad luck to be superstitious ... :D

Tags: