Getting more SRB thrust from Ares

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If the top segment doesn't have a hollow center it would have to burn from the end. The result would be a longer burn at a reduced thrust. Wouldn't this also reduce the higher g forces close to burn out? <br />Posted by samkent</DIV></p><p>It might depending on the web in the head end.&nbsp; But remember that the igniter fits in the front end and fires into the centerbore. So you have a significant ignition problem to contend with.&nbsp; That is an awfully long motor for an aft-end igniter, and aft-end igniters come with their own set of problems.&nbsp; I have only seem them used in very short motors, and not without some difficulty in design.&nbsp; Most of them are pyrotechnic, as opposed to pyrogen.&nbsp; I am aware of only one pyrogen aften end igniter ever used, and that did not make it into production.&nbsp; This motor is way to big for a pyrotechnic igniter.&nbsp; It needs a very large pyrotechnic design.</p><p>Why do you want to reduce the g load just prior to tailoff ?&nbsp; Normally you reduce it to control max q which usually occurs earlier.&nbsp; That is done by tailoring the propellant grain geometry.&nbsp; Generally what you want is a sharp tailoff, after which the motor is jettisoned, and that can be done, and in fact is normally done.&nbsp; You also want a very uniform and usually quick build-up to thrust at ignition, and that is why pyrotechnic igniters are not favored for large motors.</p><p>End burners come with their own set of problems -- much increased insulator exposure time, "coning", ...&nbsp; They are not normally used in large motors -- I can't think of a single instance.&nbsp; I can think of a couple of head-end grain designs, but only for small motors with low length/diameter ratios.&nbsp; There it is done to maximize propellant loading in a small package, but Ares is not a candidate for that approach.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I see the Ares V SRBs might get even larger.&nbsp; However, couldn't the Ares managers pull a page from the Atlas V and allow the number of SRBs attached to vary depending on needs?&nbsp; I figure an extra SRB would provide more thrust than extra segements. <br />Posted by willpittenger</DIV><br /><br />Why not get rid of the SRBs alltogether and boost the ares with an LTA (Lighter Than Air) system</p><p>&nbsp;</p><p>see thread "Rocket Powered Blimps" in the Space Science and Astronomy section</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Why not get rid of the SRBs alltogether and boost the ares with an LTA (Lighter Than Air) system&nbsp;see thread "Rocket Powered Blimps" <br />Posted by BrianSlee</DIV><br /><br />Would also work well with getting rid of the SRBs and associated risk for the the DsD concept. <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Why not get rid of the SRBs alltogether and boost the ares with an LTA (Lighter Than Air) system&nbsp;see thread "Rocket Powered Blimps" <br />Posted by BrianSlee</DIV><br />&nbsp;</p><p>Becaue you would be trading a well-known and proven approach for one that is speculative with no history, rather late in the program.&nbsp; LTA systems are not at a sufficiently high technical readiness level for a system to be used in the near term.</p> <div class="Discussion_UserSignature"> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;Becaue you would be trading a well-known and proven approach for one that is speculative with no history, rather late in the program.&nbsp; LTA systems are not at a sufficiently high technical readiness level for a system to be used in the near term. <br />Posted by DrRocket</DIV><br /><br />Dr. Rocket,</p><p>&nbsp; Are you talking about a the same well-known and proven approach that took out the first space shuttle?</p><p>And I am pretty sure I could attain a high enough TRL rating to put many tons of mass in orbit (even if its only cargo) before one of the SRB based Ares ever sees a launch pad.&nbsp;</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[samkent]

You would not have to change the method of ignition at all. Remember you are only changing the top segment to an end burn. ie no hollow center to it. The other segments still have the hollow center.

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Dr. Rocket,&nbsp; Are you talking about a the same well-known and proven approach that took out the first space shuttle?Posted by BrianSlee</DIV><br /><br />That was not a fault of the SRB (Solid Rocket Booster) system, that was a fault of the humans using the system.</p><p>And how well proved is your system? How many tests have been completed? </p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You would not have to change the method of ignition at all. Remember you are only changing the top segment to an end burn. ie no hollow center to it. The other segments still have the hollow center. <br />Posted by samkent</DIV></p><p>The igniter goes in the top segment and fires into the centerbore.&nbsp; No hole, no place for the fire to go.<br /></p> <div class="Discussion_UserSignature"> </div>

 

[Zipi]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The igniter goes in the top segment and fires into the centerbore.&nbsp; No hole, no place for the fire to go. <br />Posted by DrRocket</DIV><br /><br />Can the igniter be as long as the top segment? If the top segment would only have a tight hole for the igniter? <div class="Discussion_UserSignature"> </div>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That was not a fault of the SRB system, that was a fault of the humans using the system.And how well proved is your system? How many tests have been completed? <br />Posted by MeteorWayne</DIV><br /><br />OK but if you could remove that kind of event from your risk matrix how much of an impact would it have on your FMECA (Failure Modes Effects and Criticality Analysis).&nbsp; Oh and others like engine failure, choked flow condition....etc <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Dr. Rocket,&nbsp; Are you talking about a the same well-known and proven approach that took out the first space shuttle?And I am pretty sure I could attain a high enough TRL rating to put many tons of mass in orbit (even if its only cargo) before one of the SRB based Ares ever sees a launch pad.&nbsp; <br />Posted by BrianSlee</DIV></p><p>I am talking about that basic system, although it has been modified slightly since then.&nbsp; And those SRBs did exactly what would be expected under the circumstances.&nbsp; That is what happens when one breaks discipline and launches outside of the qualification parameters.&nbsp; Even then there is a bit more to that story.</p><p>If you think that you could achieve a TRL of 8 in the time frame contemplated for the Ares V vehicle, then you simply do not understand the problem.&nbsp; You positive statement to the contrary is proof that you don't understand.</p> <div class="Discussion_UserSignature"> </div>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I am talking about that basic system, although it has been modified slightly since then.&nbsp; And those SRBs did exactly what would be expected under the circumstances.&nbsp; That is what happens when one breaks discipline and launches outside of the qualification parameters.&nbsp; Even then there is a bit more to that story.If you think that you could achieve a TRL of 8 in the time frame contemplated for the Ares V vehicle, then you simply do not understand the problem.&nbsp; You positive statement to the contrary is proof that you don't understand. <br />Posted by DrRocket</DIV><br /><br />All I can say is I am ready to put my money where my mouth is.&nbsp; I understand the R&D process and how it relates to the acquisition process and I am not prone to saying I can do things that I am not really sure&nbsp;I can do given the appropriate resources. <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I am talking about that basic system, although it has been modified slightly since then.&nbsp; And those SRBs did exactly what would be expected under the circumstances.&nbsp; That is what happens when one breaks discipline and launches outside of the qualification parameters.&nbsp; Even then there is a bit more to that story.If you think that you could achieve a TRL of 8 in the time frame contemplated for the Ares V vehicle, then you simply do not understand the problem.&nbsp; You positive statement to the contrary is proof that you don't understand. <br />Posted by DrRocket</DIV><br /><br />What is TRL again? <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>All I can say is I am ready to put my money where my mouth is.&nbsp; I understand the R&D process and how it relates to the acquisition process and I am not prone to saying I can do things that I am not really sure&nbsp;I can do given the appropriate resources. <br />Posted by BrianSlee</DIV><br /><br />Actually, not your money, OPM <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Actually, not your money, OPM <br />Posted by MeteorWayne</DIV><br /><br />Actually yes my money.&nbsp; To this point I have over $100k of my own money and thousands of man hours worth of work invested. <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>And how well proved is your system? How many tests have been completed? <br />Posted by MeteorWayne</DIV><br /><br />In the case of TRL I am using mature off the shelf technologies which presents a much lower risk to the program as a result of a technology shortfall.&nbsp; i.e. everything I am going to use is already developed scientifically so I am not depending on a breakthrough or products from some R&D effort to support the program. <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>In the case of TRL I am using mature off the shelf technologies which presents a much lower risk to the program as a result of a technology shortfall.&nbsp; i.e. everything I am going to use is already developed scientifically so I am not depending on a breakthrough or products from some R&D effort to support the program. <br />Posted by BrianSlee</DIV></p><p>Essentially all that a TRL 1 requires is no breakthroughs in understanding of the laws of physics.&nbsp; Before you start launching real payloads you need a TRL 8.&nbsp; And that requires a lot of hard and expensive engineering work.&nbsp; To get there is a long, rigorous, and expensive process.</p><p>The science that you are looking at may be off the shelf.&nbsp; The technology is not even close.</p> <div class="Discussion_UserSignature"> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Essentially all that a TRL 1 requires is no breakthroughs in understanding of the laws of physics.&nbsp; Before you start launching real payloads you need a TRL 8.&nbsp; And that requires a lot of hard and expensive engineering work.&nbsp; To get there is a long, rigorous, and expensive process.The science that you are looking at may be off the shelf.&nbsp; The technology is not even close. <br />Posted by DrRocket</DIV><br /><br />Do you sit on a TRL Review Board?</p><p>Does TRL matter for commercial purposes?</p><p>And I respect your opinion but I also disagree with it once the FEA and CFDA are completed and validated it becomes an integration effort with the exception of the LTA component and&nbsp;I have lots of ways to mitigate risks in testing that part which would allow me an accelerated schedule.</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Do you sit on a TRL Review Board?Does TRL matter for commercial purposes?And I respect your opinion but I also disagree with it once the FEA and CFDA are completed and validated it becomes an integration effort with the exception of the LTA component and&nbsp;I have lots of ways to mitigate risks in testing that part which would allow me an accelerated schedule. <br />Posted by BrianSlee</DIV></p><p>{pet peeve rant on}<br /><br />Since both of you apparently chose not to answer my rather reasonable query, I looked up TRL.</p><p>http://en.wikipedia.org/wiki/Technology_Readiness_Level</p><p>Now I can understand WTF you are talking about.</p><p>I think it's rude to ignore requests for acronym decoding. After all, we're all not rocket scientists here.</p><p>Sometimes people who have no foundation for what they are saying hide beneath them to sound authoritative. I'm not saying that's the case. I always try and make it a point, just as peer reviewed journals do, to define an acronym the first time it is used. That's fine for a journal. In this environment, I don't think it's unreasonable to do decoding when requested.</p><p>{pet peeve rant off}</p><p>Wayne</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>{pet peeve rant on}Since both of you apparently chose not to answer my rather reasonable query, I looked up TRL.http://en.wikipedia.org/wiki/Technology_Readiness_LevelNow I can understand WTF you are talking about.I think it's rude to ignore requests for acronym decoding. After all, we're all not rocket scientists here.Sometimes people who have no foundation for what they are saying hide beneath them to sound authoritative. I'm not saying that's the case. I always try and make it a point, just as peer reviewed journals do, to define an acronym the first time it is used. That's fine for a journal. In this environment, I don't think it's unreasonable to do decoding when requested.{pet peeve rant off}Wayne <br />Posted by MeteorWayne</DIV><br /><br />Apologies</p><p>I thought I had answered your question.&nbsp; I did not know you were wanting more detailed info on the process</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>ApologiesI thought I had answered your question.&nbsp; I did not know you were wanting more detailed info on the process <br />Posted by BrianSlee</DIV><br /><br />No, I just wanted the detail of what TRL stood for. That's not more detail, that's any detail <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-smile.gif" border="0" alt="Smile" title="Smile" />&nbsp;. We all should make it a rule to define any acronyms we use the first time in a thread. It's basic respect for the other thread viewers.</p><p>BTW, I have done the same thing quite often. I always try and go back and correct that, and would certainly consider a request from anyone for decoding a high priority, as it only takes a few seconds.</p><p>However, this discussion is off topic, so let's just get back to Ares!</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>No, I just wanted the detail of what TRL stood for. That's not more detail, that's any detail &nbsp;. We all should make it a rule to define any acronyms we use the first time in a thread. It's basic respect for the other thread viewers.BTW, I have done the same thing quite often. I always try and go back and correct that, and would certainly consider a request from anyone for decoding a high priority, as it only takes a few seconds.However, this discussion is off topic, so let's just get back to Ares! <br />Posted by MeteorWayne</DIV><br />&nbsp;</p><p>Sorry, I did not see your request.&nbsp; I did however, start out by refering to a techology readiness level in the post that kicked off this part of&nbsp;the discussion.</p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Do you sit on a TRL Review Board?Does TRL matter for commercial purposes?And I respect your opinion but I also disagree with it once the FEA and CFDA are completed and validated it becomes an integration effort with the exception of the LTA component and&nbsp;I have lots of ways to mitigate risks in testing that part which would allow me an accelerated schedule. <br />Posted by BrianSlee</DIV></p><p>No I do not sit on a TRL review board.&nbsp; I told you that I am retired.&nbsp; However, I have been actively involved in quite a few rocket development programs, and composite structures work.</p><p>Gernerally speaking the term TRL is used by NASA or the DOD, so is not immediately applicable to a purely commercial venture.&nbsp; On the other hand you were talking about using the technology in lieu of the Ares systems that are under development for NASA, so it is most certainly applicable in that context.</p><p>Finite element analyses and computational fluid dynamics analyses are commonly performed throughout a development program and often afterwards to diagnose and correct issues that arise later.&nbsp; They are often performed very early, during proposal preparation before a contract is even awarded and many times after that during a development program.&nbsp; If all that you have is that sort of analysis that ought to get you to about a TRL of 3.&nbsp; You are a very long way from just an integration effort when the analysis is complete.&nbsp; There is a lot of testing needed to validate the analysis and more analysis as pieces come together and more testing and more analysis and ... </p><p>Just for your composite parts you will need material testing, under various environments, the so-called hot-wet tests probably being the most critical.&nbsp; You will need to test the pieces, the attachment mechanisms, and substructures.&nbsp; Each piece part will have to built and tested. Each test will reqjuire a fnite element analysis and comparison with test data from a large number of strain gauges. Then you need to address the structure to be built of those pieces. You will probably need to perform some sort of modal testing to support the dynamics analysis, and you will likely need quite a bit of destructive testing to validate the structural analysis.&nbsp; And this is only a quick overview of what will probably be a lot more involved analysis and testing. just for the composite framwork.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Actually yes my money.&nbsp; To this point I have over $100k of my own money and thousands of man hours worth of work invested. <br />Posted by BrianSlee</DIV></p><p>$100k for this sort of program won't last an hour.</p><p>Let me give you a yardstick, though perhaps a poor one.&nbsp; A while back I was working on a proposal for moving the manufacture of a rocket motor from one location to another.&nbsp; The design existed.&nbsp; All we had to do was to figure out how to manufacture it in another location, using somewhat different equipment,&nbsp;without changing it too much.&nbsp; We spent about&nbsp;2 months putting that proposal together and were spending well in excess of $20,000 per day.&nbsp; That was just in trying to figure out how to do the job and what it would cost.&nbsp; We didn't actually make anything during that period.&nbsp; This work was quite a bit less complex and less risky than development of a system with an entirely new approach.</p> <div class="Discussion_UserSignature"> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>No I do not sit on a TRL review board.&nbsp; I told you that I am retired.&nbsp; However, I have been actively involved in quite a few rocket development programs, and composite structures work.</DIV><br /><br />Dr. Rocket,</p><p>&nbsp; I too can claim some experience in the field.&nbsp; I have been working for, with, and around the government for 28 years.&nbsp; I have done many jobs, from turning a wrench on advanced airborne systems to briefing acquisition authority and senior executive leadership as a member of a program managers staff.&nbsp; I am intimately familiar with the acquisition process and how it relates to all phases of the life cycle for major systems.&nbsp; Which also means that I have the experience to navigate the process very effectively.</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>