Comments on: Are Those Nozzles "Thrust Augmented"? http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/ Random Musings from the Warped Minds of Jonathan Goff, Ken Murphy, John Hare, and Kirk Sorensen Thu, 02 Sep 2010 05:17:09 -0700 http://wordpress.org/?v=2.8.4 hourly 1 By: Roderick Reilly http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-4783 Roderick Reilly Fri, 29 May 2009 23:07:10 +0000 http://selenianboondocks.com/?p=497#comment-4783 Jon: I ead your exchange at the links to the other blog. According to the Aerojet PDF file, they dealt with the fuel injection issue by going back to their research on scramjet fuel injection. I think that takes care of the issue "Antonio" brought up that he thought was a barrier. Jon:

I ead your exchange at the links to the other blog. According to the Aerojet PDF file, they dealt with the fuel injection issue by going back to their research on scramjet fuel injection. I think that takes care of the issue “Antonio” brought up that he thought was a barrier.

]]> By: Roderick Reilly http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-4781 Roderick Reilly Fri, 29 May 2009 23:01:47 +0000 http://selenianboondocks.com/?p=497#comment-4781 Hey, how'd I miss this discussion? Was I hybernating? I am a huge fan of TAN. Of course, we don't actually know if this HC Boost is TAN, but it sure sounds like it. Jon, Did you ever see the PDF file by Aerojet on TAN? I can send you a copy if you like. Hey, how’d I miss this discussion? Was I hybernating? I am a huge fan of TAN. Of course, we don’t actually know if this HC Boost is TAN, but it sure sounds like it.

Jon, Did you ever see the PDF file by Aerojet on TAN? I can send you a copy if you like.

]]> By: Jon Goff http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-3052 Jon Goff Wed, 27 Aug 2008 18:51:00 +0000 http://selenianboondocks.com/?p=497#comment-3052 Anonymous,<br/>Thanks for the heads up. I found Antonio's comment here:<br/>http://forum.nasaspaceflight.com/index.php?topic=11604.msg309489#msg309489<br/><br/>and posted a reply here:<br/>http://forum.nasaspaceflight.com/index.php?topic=10787.msg310119#msg310119<br/><br/>I have a *lot* of respect for Antonio and his team, but even experts in the field can sometimes jump to conclusions about other peoples' technologies. Some of his concerns are valid, but others not as much.<br/><br/>~Jon Anonymous,
Thanks for the heads up. I found Antonio’s comment here:
http://forum.nasaspaceflight.com/index.php?topic=11604.msg309489#msg309489

and posted a reply here:
http://forum.nasaspaceflight.com/index.php?topic=10787.msg310119#msg310119

I have a *lot* of respect for Antonio and his team, but even experts in the field can sometimes jump to conclusions about other peoples’ technologies. Some of his concerns are valid, but others not as much.

~Jon

]]> By: Anonymous http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-3051 Anonymous Wed, 27 Aug 2008 04:33:00 +0000 http://selenianboondocks.com/?p=497#comment-3051 I can no longer find the post, but Antonioe recently posted on a NASASpaceflight.com forum a critique of TAN, with some very good points. He considers it a bandaid when one can't stage to change from a low expansion engine to a high expansion one. This is well outside of my realm, but his points made as much sense as yours. I can no longer find the post, but Antonioe recently posted on a NASASpaceflight.com forum a critique of TAN, with some very good points. He considers it a bandaid when one can’t stage to change from a low expansion engine to a high expansion one. This is well outside of my realm, but his points made as much sense as yours.

]]> By: Jon Goff http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-2886 Jon Goff Mon, 02 Jun 2008 14:35:00 +0000 http://selenianboondocks.com/?p=497#comment-2886 Will,<br/>Did you see the previous article I wrote on the topic, that included a link to the Aerojet paper?<br/><br/>As for bringing back the F-1, unfortunately at this point it would be little easier than developing a clean-sheet engine, and would have nowhere near as good of performance or even necessarily reliability. It's an old design with at least some deprecated technology and materials, and with no remaining manufacturing experience.<br/><br/>~Jon Will,
Did you see the previous article I wrote on the topic, that included a link to the Aerojet paper?

As for bringing back the F-1, unfortunately at this point it would be little easier than developing a clean-sheet engine, and would have nowhere near as good of performance or even necessarily reliability. It’s an old design with at least some deprecated technology and materials, and with no remaining manufacturing experience.

~Jon

]]> By: Will Doohan http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-2885 Will Doohan Mon, 02 Jun 2008 04:52:00 +0000 http://selenianboondocks.com/?p=497#comment-2885 After reading this post and the comments, I still don't see an explanation of thrust augmentation. And if they want an engine with more power than the RD-180, couldn't they re-build the F-1 engine from the Saturn V ? (I've been reading a lot of stuff about the Apollo program lately and am semi-obsessed with it :-P . I know it's not gonna happen, but it would be cool to see them re-build those rockets.) After reading this post and the comments, I still don’t see an explanation of thrust augmentation. And if they want an engine with more power than the RD-180, couldn’t they re-build the F-1 engine from the Saturn V ? (I’ve been reading a lot of stuff about the Apollo program lately and am semi-obsessed with it :-P . I know it’s not gonna happen, but it would be cool to see them re-build those rockets.)

]]> By: Anonymous http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-2838 Anonymous Thu, 24 Apr 2008 05:21:00 +0000 http://selenianboondocks.com/?p=497#comment-2838 Precisely, No, and Perhaps but I doubt it, in that order. <br/><br/>It really looks like an "excuse" to raise prices. <br/>It is hard to believe that they would charge $10M for losing a diagnostic recovery.<br/>They have been very explicit about the items for which they are charging. A dry nitrogen purge is listed among the "extras" that cost more. They have not appeared to hide or "cover" any charges.<br/><br/>It is a strain to read this as ambiguous.<br/><br/>Good luck getting more information from them. My contact is not responding. Until then, it looks a lot like tens of millions of dollars are embedded until they work out reusability, which is a groundbreaking technology. Precisely, No, and Perhaps but I doubt it, in that order.

It really looks like an “excuse” to raise prices.
It is hard to believe that they would charge $10M for losing a diagnostic recovery.
They have been very explicit about the items for which they are charging. A dry nitrogen purge is listed among the “extras” that cost more. They have not appeared to hide or “cover” any charges.

It is a strain to read this as ambiguous.

Good luck getting more information from them. My contact is not responding. Until then, it looks a lot like tens of millions of dollars are embedded until they work out reusability, which is a groundbreaking technology.

]]> By: Jon Goff http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-2833 Jon Goff Wed, 23 Apr 2008 06:23:00 +0000 http://selenianboondocks.com/?p=497#comment-2833 Anonymous,<br/>I actually read the same users guide you were referring to (I saw the link there on nasaspaceflight.com). The phrasing actually is still ambiguous. While it says that non-recoverability is the excuse for the $10M surcharge, it doesn't specifically say why. It could be they expect the second stage to cost $10M, so for expending it you have to buy it. Or it could also have to do with them wanting to recover the stage just for post-flight inspection purposes. Or it could even just be that they wanted to provide a valid sounding excuse to cover some of their other additional expenses that a lunar mission would occur.<br/><br/>I almost had an opportunity last night to get more info on this, but until I've had some clarification from them, I'm at least not going to assume that's what they mean.<br/><br/>~Jon Anonymous,
I actually read the same users guide you were referring to (I saw the link there on nasaspaceflight.com). The phrasing actually is still ambiguous. While it says that non-recoverability is the excuse for the $10M surcharge, it doesn’t specifically say why. It could be they expect the second stage to cost $10M, so for expending it you have to buy it. Or it could also have to do with them wanting to recover the stage just for post-flight inspection purposes. Or it could even just be that they wanted to provide a valid sounding excuse to cover some of their other additional expenses that a lunar mission would occur.

I almost had an opportunity last night to get more info on this, but until I’ve had some clarification from them, I’m at least not going to assume that’s what they mean.

~Jon

]]> By: Anonymous http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-2832 Anonymous Wed, 23 Apr 2008 06:00:00 +0000 http://selenianboondocks.com/?p=497#comment-2832 "And worst of all, from experimental retrieval of the first stage to a baseline plan for first and second stage reuse."<br/><br/>"Careful, we *don't* yet know that for sure--that's only extrapolation based on one line in a new payload users guide."<br/><br/>Not so, although I can be less careful than you. In the new "Falcon Launch Vehicle Lunar Capabilities Guide" issued earlier this month, there is this line on page 10 under Price: "Missions to Trans Lunar Injection will have an additional charge of $10M<br/>since the second stage is non‐recoverable."<br/><br/>It doesn't get much clearer than that. Plus it fits with the user's guide pricing for the Falcon 9 on their web page. They plan to charge an extra $10.5M for the last 500kg of performance to GTO and $10.0M for TLI over LEO missions. That was not explicit, but the new quote is. “And worst of all, from experimental retrieval of the first stage to a baseline plan for first and second stage reuse.”

“Careful, we *don’t* yet know that for sure–that’s only extrapolation based on one line in a new payload users guide.”

Not so, although I can be less careful than you. In the new “Falcon Launch Vehicle Lunar Capabilities Guide” issued earlier this month, there is this line on page 10 under Price: “Missions to Trans Lunar Injection will have an additional charge of $10M
since the second stage is non‐recoverable.”

It doesn’t get much clearer than that. Plus it fits with the user’s guide pricing for the Falcon 9 on their web page. They plan to charge an extra $10.5M for the last 500kg of performance to GTO and $10.0M for TLI over LEO missions. That was not explicit, but the new quote is.

]]> By: Jon Goff http://selenianboondocks.com/2008/04/are-those-nozzles-thrust-augmented/comment-page-1/#comment-2823 Jon Goff Mon, 21 Apr 2008 18:54:00 +0000 http://selenianboondocks.com/?p=497#comment-2823 Anonymous,<br/><i>Your second concept, Jon: I was saying that having the pressurized fuel flowing around the regeneratively cooled nozzle would be a benefit. They have already implemented the plumbing to bring the fuel, now used as coolant, across the joint actuated by the guidance system.</i><br/><br/>Ah, ok. Gotcha. Actually, I'm not sure if that would be the best approach, here's why. For a pump, the required power scales roughly linearly with pump volume flow, pressure. At least some of the fluid in the nozzle is going into the main combustion chamber, and therefore has to be at fairly high pressure to overcome the pressure drop of the cooling channels and the pressure drop at the injectors. So, it's probably somewhere on the order of 1200-1500psi at the inlet to the nozzle. For thrust augmentation however, you only really need about 150-300psi injector pressure. Which means that you'd be wasting lots of pump power to get the thrust augmentation. <br/><br/>A much better approach would be to tap off a little of the high pressure flow, and either use it to run a lower pressure hydraulic turbine, or run some sort of jet pump. That way you can get a lot more TAN flow for much less pump power. As it is, the pumps are on the engine side of the gimbal setup, so you'd still get the same benefit.<br/><br/>As it is though, I doubt they'll be doing a TAN upgrade anytime soon, because as you point out, they have way too much on their place already. It makes a lot of performance sense, but just getting something working well enough to start succesfully putting payloads into orbit probably is (and should be) a higher priority.<br/><br/><i>And worst of all, from experimental retrieval of the first stage to a baseline plan for first and second stage reuse.</i><br/><br/>Careful, we *don't* yet know that for sure--that's only extrapolation based on one line in a new payload users guide. For all we know, his pricing could still be based on not actually reusing either stage, but he may want to do an extra surcharge because they won't be able to get the stage back for inspection or something like that.<br/><br/>IOW, I'd be careful about drawing too many conclusions quite yet.<br/><br/>~Jon Anonymous,
Your second concept, Jon: I was saying that having the pressurized fuel flowing around the regeneratively cooled nozzle would be a benefit. They have already implemented the plumbing to bring the fuel, now used as coolant, across the joint actuated by the guidance system.

Ah, ok. Gotcha. Actually, I’m not sure if that would be the best approach, here’s why. For a pump, the required power scales roughly linearly with pump volume flow, pressure. At least some of the fluid in the nozzle is going into the main combustion chamber, and therefore has to be at fairly high pressure to overcome the pressure drop of the cooling channels and the pressure drop at the injectors. So, it’s probably somewhere on the order of 1200-1500psi at the inlet to the nozzle. For thrust augmentation however, you only really need about 150-300psi injector pressure. Which means that you’d be wasting lots of pump power to get the thrust augmentation.

A much better approach would be to tap off a little of the high pressure flow, and either use it to run a lower pressure hydraulic turbine, or run some sort of jet pump. That way you can get a lot more TAN flow for much less pump power. As it is, the pumps are on the engine side of the gimbal setup, so you’d still get the same benefit.

As it is though, I doubt they’ll be doing a TAN upgrade anytime soon, because as you point out, they have way too much on their place already. It makes a lot of performance sense, but just getting something working well enough to start succesfully putting payloads into orbit probably is (and should be) a higher priority.

And worst of all, from experimental retrieval of the first stage to a baseline plan for first and second stage reuse.

Careful, we *don’t* yet know that for sure–that’s only extrapolation based on one line in a new payload users guide. For all we know, his pricing could still be based on not actually reusing either stage, but he may want to do an extra surcharge because they won’t be able to get the stage back for inspection or something like that.

IOW, I’d be careful about drawing too many conclusions quite yet.

~Jon

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