Shuttle SRB derivative(s) replacing the EELVs entirely?

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dwightlooi

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The current favorite for putting Americans into space following the demise of the space shuttle spears to be a booster based on stacking a hydrogen upper stage on top of the Shuttle’s massive Solid Rocket Booster (SRB). There is no shortage of critics as well as proponents of this arrangement. But, <b>let’s assume that it works for a minute. If it works, is safe and does lift 22 tons to LEO with a 100 ton class upper stage – as ATK Thiokol is promoting it as being capable of doing – doesn’t it make the EELVs redundant?</b><br /><br />I mean really! Let’s take a step back and consider this. <b>Why fly a Delta IV Heavy with three hydrogen fueled boosters and three RS-68 engines to put 26 tons into low earth orbit? Why fly an Atlas V with a highly stressed, staged combustion, Russian made kerosene engine to put 12 tons into orbit? Why even fly a single Delta IV medium with the RS-68 engine its cryogenic isogrid fuel tank to lift 8 tons? Why bother?</b> Solids are simpler, cheaper and make a lot of lift off thrust. Why not simply have SRB derived rockets do all the work? A simple system such as follows can theoretically meet all our main stream space launch needs:-<br /><br />(1) <b>Baseline LV</b> -- a single 4 segment SRB topped with a 5m, 100 ton, upper stage with a J2 engine for 22 tons of payload to LEO.<br /><br />(2) <b>Growth LV</b> – a single 5 segment SRB with the advanced RLX expander cycle engine and a 150 ton upper stage for a 30 ton LEO capacity (which eclipses even the Delta IV heavy and is a simple 2 stage rocket with just one inherently simple expander type liquid motor).<br /><br />(3) <b>Light LV</b> – versions of the baseline vehicle with only two or three SRB segments, and a 50 ton upper stage to handle the 8 to 12 ton payloads common to commercial launches and currently served by the Arianne V and EELVs. When the growth version of the baseline vehicle enters service, the upper stage engine can be standardized to a derated RLX providing some increase in pay
 
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gunsandrockets

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Why? Because the EELV were developed with the companies own money not with USAF money. Whereas NASA has budget $5 billion for development of the SRB derived CEV launcher.<br /><br />The real reason NASA is going with SRB derived hardware is because it subsidizes the NASA plan for a Shuttle derived heavy launch vehicle. Without the subsidy the SDHLV becomes even more expensive to develop.
 
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dwightlooi

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I think the US space program, and space industry in general for that matter, has to stop wasting resources. We'll get a lot more done if we get all the parties together and have one family of launch vehicles. We should also stop wasting money on studies and abortive projects. DO NOT develop anything unless we are commited to following through and getting it operational.
 
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tap_sa

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<font color="yellow">"We should also stop wasting money on studies and abortive projects. DO NOT develop anything unless we are commited to following through and getting it operational."</font><br /><br />Indeed. Why waste more money trying to materialize yet another paper-rocket such as SRB-Stick when we have two operational EELVs which just need higher flight rates to become more cost-effective.
 
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elguapoguano

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<font color="yellow">We'll get a lot more done if we get all the parties together and have one family of launch vehicles.</font><br /><br />Tried that once. Didn't seem to work out that well. We put all our eggs in one basket with Shuttle... <div class="Discussion_UserSignature"> <font color="#ff0000"><u><em>Don't let your sig line incite a gay thread ;>)</em></u></font> </div>
 
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najab

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The single stick SRB is not a paper rocket - most of the required hardware is flying currently or has been flown in the past.
 
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gladiator1332

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How can you say that a LV that has its first stage and its second stage (if they go with the SSME upperstage) currently flying is a paper rocket?<br />As much as I like the Shuttle, I see that it has no place in the VSE. SO you're telling me you would like to throw the CEV in the cargo bay of the Shuttle? THat doesn't make any sense.<br />Or do you mean Shuttle C? That requires about the same modification that the SRB Launcher requires. They both have all their components currently flying (expect the Shuttle C cargo pod)
 
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frodo1008

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I made this reply to another thread that was comparing the relative safety and reliability of liquid vs. solid engine systems. I thought it might be of use here. Solids might be just fine for placing materials into LEO, but like Wherner Von Braun I do NOT like them for placing human beings into orbit!! See my reasons below:<br /><br /><br />“There is another reason why liquid engines are safer that the excellent post of propforce. That is simply that you can’t use the very same solid for your actual launch vehicle that you used to test the safety of your solid systems with! <br /><br />This means that you MUST depend completely on your manufacturing processes to make sure that every single motor is EXACTLY the same as those that you tested. Now I know that the solid motor industry have actually done a very good job of doing this, but it IS still a factor in engines safety.<br /><br />On the other hand every single liquid engine that is built is given a "Green Run", this means that the engine is prior run enough to find out if there are any problems with that particular engine. Then this VERY SAME engine is shipped and used on the actual launch vehicle itself!<br /><br />This can’t possibly be done with solids as when you test a solid, it is history, it IS gone! Used up, no more!<br /><br />THIS is why no less a rocket scientist than Wherner Von Braun insisted that there would be no solids used to propel, or even help propel human beings into space!<br />Well, he did relent in that the Apollo capsule escape system motor was solid. But of course, it was very sincerely hoped that system would never have to be used!<br /><br />Now, even with this inherent advantage even liquid engines have been known to fail. We are talking temperatures and pressure here that are far higher than even jet engines! But, this applies equally to both liquid and solid systems, and if you don't think that such temperatures and pressures can also make solids fail, then think of the Challenger acci
 
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dwightlooi

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Yes, you cannot perform an actual test a particular solid booster and subsequently use it on a flight. But this is only a small piece of the reliability and safety puzzle. Without a doubt, solids are simpler. They have no moving parts involved in generating thrust. And any moving parts it has -- such as gimballing mechanisms -- are also present in liquids in a more complex form. This means that solids have inherently less things to fail. Another important factor is that liquids have a tendency to blow up if the contents of fuel and oxidizer tanks were to mix and ignite. This can be the result of a structural failure of the tanks due to cryogenic stress or physical flaw. It can also be due to an explosion in a failed liquid engine, or due to external factors such as in the case of the challenger's SRBs burning through the hydrogen tank. Solids generally cannot blow up. The propellants cannot become explosive; they burn but they cannot explode. If a case rupture or o-ring failure occurs you may get hot gases exiting from the side of the booster. This will cause a loss in thrust and probably cause a change in vector due to the side jet. If the gimballing gear fails, you may not be able to steer the rocket. But next to something blowing sky high, these are relatively benign failure modes. It gives you plenty of time to activate your launch escape system and get the crew off the malfunctioning LV. When a liquid biooster explodes, chances are you will have no chance to get the crew to safety. Solids also do not need cryogenic fuels or oxidizers. This makes them a lot easier to work with and launch. There is no fueling or defueling. No foam to shed. No worries about low temperature fatigue of the tanks.
 
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tap_sa

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<font color="yellow">"The single stick SRB is not a paper rocket - most of the required hardware is flying currently or has been flown in the past."</font><br /><br />Before we hear things like roll control for the SRB and exact size of the 2nd stage and what engine it uses, it's a paper rocket. Something that you, me, anybody can slap together by googling data from astronautix.com and do a pretty rendering to go with it. <br /><br />edit: Took a quick re-look at safesimplesoon.com for the roll control issue, looks like Thiokol would like to put fins at the SRBs base. Just like that, wouldn't affect the previous man-rating?
 
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najab

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><i> Just like that, wouldn't affect the previous man-rating?</i><p>Of course it would. But the engineering required to certify that modification has to be less involved and expensive than for an up-rated 5 core EELV derivative, wouldn't you say?</p>
 
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tap_sa

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<font color="yellow">"the engineering required to certify that modification has to be less involved and expensive than for an up-rated 5 core EELV derivative, wouldn't you say?"</font><br /><br />It's hard to say without knowing how long Thiokol have had plans for the fins. Are they something relatively new for the new situation or something that was planned long ago just in case. I'd imagine five core EELV has been on the drawing boards since the inception of that program, the definitive word is 'common' in the CCB/CBC <img src="/images/icons/wink.gif" /><br /><br />And if we talk about Stick-CEV, five core EELV is premature. The Thiokol marketing site promotes 48-55K lbs (21.8-25 tonnes) Stick boosters for 'tomorrow', meaning it's the next step. DeltaIV Heavy can deliver this as is. Atlas V 551 can do a little over 20 tonnes with just one core and five solids, although this configuration hasn't flown yet, 521 (two solids) has. I can imagine Thiokiol trying to do everything to lobby the CEV become too heavy for current EELVs.<br /><br />IMO SDHLV, the sidemounted version makes sense for heavy lift, requiring the least redesign and utilizing the existing infrastructure most efficienctly without big modifications.<br /><br />200t inline behemoths sound great as long as you just keep to imagining the majestic launch of that thing instead of financial issues. I doubt any of those inline versions, starting from 120t payload, fly for less than $1B/launch. And that's just the launch cost. Now, think of the payload, 120-200 tonnes of brand new space-hardware for exploration. What will be the $/[kg|lb] price for that? I'd SWAG it to minimum of ten times the launch cost, despite most of that mass being propellant for the moon/mars spaceship.<br /><br />Btw is it really necessary to launch 100+t wet spacecraft with 2/3rd or more of the mass being propellant? Is it really that hard to launch, say, 25t dry craft and another 2-3 launches with fuel tanks and assemble the thing i
 
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gladiator1332

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<blockquote><font class="small">In reply to:</font><hr /><p> And if we talk about Stick-CEV, five core EELV is premature. The Thiokol marketing site promotes 48-55K lbs (21.8-25 tonnes) Stick boosters for 'tomorrow', meaning it's the next step. DeltaIV Heavy can deliver this as is. Atlas V 551 can do a little over 20 tonnes with just one core and five solids, although this configuration hasn't flown yet, 521 (two solids) has. I can imagine Thiokiol trying to do everything to lobby the CEV become too heavy for current EELVs. <p><hr /></p></p></blockquote><br /><br />The with the Delta IV Heavy is that it has one launch. We don't even know if it is safe for satellites yet, and the first test launch was a little less than perfect. And Atlas hasn't eve flown a heavy configuration, you can't expect them to suddenly put 5 booster cores on it. <br /><br />Sure the SRB will have to be re-manrated, but so will the Inline and the Shuttle C. However, all of these will be easier to remanrate, whereas the EELV, which were never designed to launch manned spacecraft would be much tougher. <br /><br />
 
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nacnud

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The in line HLSDV is unlikely ever to launch people so there is no need to man rate it.
 
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frodo1008

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That is also my understanding. The safer but less powerful liquid engines to place people into orbit. And the far more powerful (it would take two of the mighty F1 engines to make up for one SRB) SRB's (and SSME's or other liquids) to heavy lift pure materials for those people to work with into orbit. It WAS an error to try to combine both jobs into one vehicle with the design of the space shuttle. But we should remember that at that time this was the first time such a vehicle had been built, so I think we can now cut the original designers and the NASA of that time a little slack! However, NOW we know better, so hopefully, and it certainly looks like Griffen is headed in that direction, we can do it right! And thus eventually bring the costs down by at least a factor of five or maybe even ten times!<br /><br />I just hope that Griffen is not forced to just rely on the SRB's to place people into orbit. But I admit from a budgetary standpoint that is what is going to be done.<br /><br /> However, there is a light at the end of the tunnel in that Burt Rutan and company will be eventually building lifting body types of vehicles for the placing of people into orbit for far less even than the SRB's can place capsules into orbit. And while Rutan's current engines are hybrids due to budgetary constraints, I think that eventually he will be using pure liquid engines, such as the linear aerospikes, which can be completely integrated into the fuselage of such lifting body craft.<br /><br />Who knows, eventually in the long term the space elevator concepts may really bring down the cost of placing BOTH people and materials all the way out to GEO! But, as I am now 62 I don't really think that I will live to see such a revolution! Oh well....
 
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