RS68 confirmed for CaLV

[frodo1008]

Bell does make many good points, but I don't just go in lock-step with his conclusions here. At the time that the original designs for the CLV and CALV were being put forth the main reason for using shuttle hardware was obvious, it was the cheapest solution that NASA could find! <br /><br />What the critics of NASA never seem to want to realize is that: IT IS THE BUDGETARY LIMITS OF A CONGRESS THAT WANTS A ROLLS ROYCE AT YUGO PRICES THAT GOVERNS WHAT NASA CAN DO, NOT TECHNICAL CONSIDERATIONS!!!!! And yes, I AM shouting here, as it sometimes seems that I must be the only one on these boards that notices this absolute truth!! Certainly every NASA administrator realizes this (If he does not initially he will learn it to his sad detriment!). <br /><br />This is because this country would rather fight useless and harmful wars than have a truly great space program. It is almost an ultimate irony that one of the truly great military men of the twentieth century: President Eisenhower, warned us against the military industrial complex. But we haven't listened, at the cost of an originally fantastic opportunity to really place mankind (with the US showing the same kind of leadership that made it the great nation it was) into space, and improve the chances of humanities very survival in the long run! So we fought a losing war in South East Asia that so crippled the space program that the kluge STS system resulted. Oh, there was just enough political power left to such an effort as NASA's to barely keep the dream alive for some 30+ years. But never enough to really do the job right!!<br /><br />And the hearts and souls of true space advocates have bleed all during this time!!<br /><br />Now here we are again! We are spending at least $150 billion dollars per year in the Middle East. In another place where the American people are finding out that we are more and more resented! Heck, most of the vast sums of wealth that we are wasting is being hid as much as possible from th

 

[mattblack]

>>Someone then e-mailed to Chris Bergen, editor of Nasaspaceflight.com, those papers and he published them in the L2 section<<<br /><br />Which has caused me to have a pragmatic, partial change of mind: Something that has not been easy for me. Truly.<br /><br />Then again; LockMart will have to PROVE their assertions, beyond graphics and bar-charts, because that's partly the reason Nasa itself went the way it did.<br /> <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[mattblack]

>>And the hearts and souls of true space advocates have bleed all during this time!!<< <br /><br />Could not have put it better myself. Once again, Frodo is one of the more articulate and soulful posters here. <br /> <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[frodo1008]

Thank you very much! You are among the elite of this forum yourself. Along with propforce, and shuttle_guy you show a degree of competence that is very much needed here!<br /><br />If I hadn't have been a physics major during my college years, I would have been an English Literature major! I personally think that the poetic side of scientists is greatly underestimated by the more Liberal Arts side of the educational spectrum. It always disturbed me how such people could assume that someone whose major was a hard science or engineering never read a book outside of his specialty! At least in my case it just wasn't true, and I really don't think that I was alone!<br /><br />I am just as awed by the writings of the likes of Chaucer, Shakespeare, and Milton as I am by the mathematics of Gauss, or the physics of Newton or Einstein!<br /><br />Even the best of the great fantasy or SCI-FI writers could become poetic on occasion. And J.R.R. Tolkien was considered to be the greatest living expert on the Anglo Saxon Epic of Beowulf!<br /><br />So, once again, Thanks for the Compliment, it means a great deal to me to be so appreciated on these boards!<br /><br />SO, Have A Great Day!<br />

 

[edkyle98]

I understand your point. I even agree with it on an emotional level (I certainly remember Challenger, because I worked at KSC at the time. I watched the crew head for the pad, I watched the failure, and I watched the devastated families return to the crew quarters afterward.) But when I look coldly at the numbers, I see solid motors showing more reliability than liquid propulsion stages - this despite the fact that the liquid engines are tested prior to flight. <br /><br />RS-27A hasn't failed, yet, but I was an eyewitness to the Delta 178 failure in 1986, when an electrical glitch caused an RS-27 to shut down. More recently, in 1993, the Atlas booster cousin of the RS-27 suffered an outright failure on AC-74, producing low thrust so that the payload didn't make the planned orbit. Shuttle Challenger had to do an Abort to Orbit when an SSME shut down. The orbit was low and the mission had to be shortened. A second near-miss occurred during a late 1990s flight, when an engine controller shut down right at liftoff and an undetected leak in a thrust chamber cooling tube caused early propellent depletion and a slightly low orbit.<br /><br />Take recent flight history as an example of what I see in the numbers. Since 2000, inclusive, there have been an even 400 space launch attempts (up to and including the Delta 4 GOES-N launch success). A full 23 of these flights failed. Seventeen of the failures (4.25%) involved liquid rocket stages. Six of the 23 failures occurred on solid-motor launchers (1.5%). None involved catastrophic solid motor failures. <br /><br />There were two solid motor nozzle failures (H-2A-F6 and M-5-4), but in both cases the solid motors actually completed their burns and the launch vehicles flew on. A Taurus suffered a momentary glitch in its second stage TVC, but didn't fly out of control. A Shavit suffered a stage separation problem. Two KT-1 launch attempts from China failed for unknown reasons.<br /><br />The recent Falcon 1 engine fire

 

[frodo1008]

I, on the other hand could go on about a whole lot more solid failures also. But there is no real point. I have already complimented ATK on their recent safety history. <br /><br />At this point that really isn't the basic problem. The problem is ATK gouging NASA for developement costs, soaring from some 1 billion to 3 billion. A 300% increase in just six months! Even the price gouging for gasoline by the oil companies pales to insignificance next to this! And just like the American gasoline consumer NASA just doesn't have the deep pockets to pay this kind of extortion!<br /><br />By the way the last failure of a Delta II (the one that blew up just over the pad, and rained down parts of a commercial satellite (thank heavens it wasn't a NASA launch) was a solids failure, but as I said that isn't the principle problem here. <br /><br />Even I defended NASA's original choice to use existing shuttle hardware, but not at these prices!

 

[barrykirk]

My own spin in this is that as far as safety goes, I would <br />believe that frequency of launch is probably a much more important factor than Solids versus Liquids.

 

[edkyle98]

I don't see much of a relationship between flight frequency and launcher reliability, though it is true that the realized failure rate more closely approaches the true failure rate as more flights accrue over the lifetime of a launch system. <br /><br />I suspect that reliability is more closely related to vehicle complexity. Launch vehicles with fewer liquid core stages tend to have lower failure rates than launchers with more stages (all else being equal), for example. Tsyklon 2 is more reliable than Tsyklon 3. Soyuz-U is more reliable than Molniya-M. Titan 2 was more reliable than Titan 3B. Etc... <br /><br />Launch vehicle simplicity extends to propulsion systems too. A solid motor is much less complex than a liquid propulsion system, which includes not only the engine but also the tank pressurization systems, etc. <br /><br /> - Ed Kyle

 

[edkyle98]

>>"The problem is ATK gouging NASA for developement costs, soaring from some 1 billion to 3 billion."<<<br /><br />This cost increase was due to the change from the already developed 4-segment RSRM to the 5-segment RSRM/B. This motor would have to be developed anyway for the CaLV, so it isn't a cost increase at all. Sure, it will cost some money to develop what will be the world's most powerful rocket, but the 5-segment motor allowed NASA to drop SSME, which will save billions of dollars over the life of the program.<br /><br /> - Ed Kyle

 

[propforce]

<font color="yellow">Launch vehicle simplicity extends to propulsion systems too. A solid motor is much less complex than a liquid propulsion system, which includes not only the engine but also the tank pressurization systems, etc. </font><br /><br />There's no question that a SRB is far less complex than a liquid prop system. The "cost" of SRB/SRM reliability is being done during manufacturing with strict quality control and lot acceptance testing (LAT). The cost is also during the motor shipment/ transport, storage, and the amount of 'touch labor' that goes into stacking the solids and mounting them on the vehicles. The worst fear of a SRB is an electro-static discharge, or errors in electrical power switching to the igniter, during vehicle stacking that could potentially take out the whole rocket as well as the whole pad along with the peopel working there at the time. IIRC, Brazil's launch pad suffered a similar fate a few years back that took out 50% of their engineers working at the pad at the time.<br /><br />A liquid system requires various parts manufacturing/ acceptance, then subsystem level assembly/ checkouts. When the rocket is put together and one starts to load cryogenic propellant, the "characteristic" of the system changes althogether, things get cold and shrink, then there's boiling and venting, valves open & close, gases purging and hissing, etc. All of sudden, you have a living & breathing beast that's eager to get out of the gate !! It's exciting to watch nevertheless <img src="/images/icons/cool.gif" /><br /><br />A liquid system is far more mission-flexible in that you can load 100% or 50% of propellant, vary engine thrust throttle timing in the trajectory from mission to mission, greater gimbaling and fine-tuning capability, not to mention higher Isp performance. It also offers a <i>smoother ride</i> as its combustion pressure oscillation is smoother than a SRB/SRM thus offers lower vibration level. While some of these adv <div class="Discussion_UserSignature"> </div>

 

[propforce]

<font color="yellow">This cost increase was due to the change from the already developed 4-segment RSRM to the 5-segment RSRM/B. This motor would have to be developed anyway for the CaLV, so it isn't a cost increase at all. Sure, it will cost some money to develop what will be the world's most powerful rocket, but the 5-segment motor allowed NASA to drop SSME, which will save billions of dollars over the life of the program. </font><br /><br />Ed,<br /><br />Can you explain the rationale switching from HTPB to PBAN propellant going from 4-segment to 5-segment SRB? My understanding is that PBAN is a lower performing propellant than HTPB, thus I don't understand why NASA/ ATK choose to go this route.<br /><br />Also, this maybe beating a dead-horse, but NASA could switch the SRB out for some variant of Atlas V and/or Delta IV first stage and save the $3 billion in qualifying the FSB. As for the argument against using the EELV, the biggest argument is the cost to "man-rate" the launcher, since NASA is very strapped for cash. But my colleague at Boeing has told me that it will cost NASA $6 billion to design and build the CLV while it would only cost $1 billion to "man-rate" the Delta IV. So what makes sense here?<br /> <div class="Discussion_UserSignature"> </div>

 

[frodo1008]

Up till this last post you did make sense. But the last is just not as true. The developement costs for the five segment were supposedly known all along to be $1 billion! After all, they already had a four segment motor anyway. If upgrading these solids costs billions then they are just too damn expensive! It would be far better to use a single RS68 (at an already developed production cost of $20 million), even if it meant using the entire Common Booster Core + RS68 (at about 40 million, or about the same as the four segment price is now). True this would give less thrust, but $2 billion would buy 50 such units alone!<br /><br />Mike Griffin is quite probably the best equiped NASA administrator for a long time, and HE is incensed by ATK's price increase! Plus I can almost quarantee that congress isn't going to give NASA such increases. It just isn't going to happen! <br /><br />ATK HAS done one useful thing however, they have re-opened up the debate for the CALV unit (and possibly even the single stick CEV unit as well). I originally thought that using the shuttle derived equipment was best for both the CEV and the CALV. But if it is going to cost this kind of money to do so, then it has become too expensive to do so. And YES the RS25 derivative of the SSME would also be expensive to develope, but Rocketdyne could have re-opened up the F1 manufacturing line for no more than ATK wants!<br /><br />However. I am still at this point for using the original 4 segment SRB (at least we know it to cost some $38 million per unit) along with the more powerful RS68 for the CALV. Heck, if you want to increase the thrust for the single stick SRB then use the old four segment and add two CBC's with RS68's to the first stage as this would even generate more thurst for that stage for the CEV than going to the five segment would! You could still use the two J2S engines for the second stage (you would have to man-rate the RS68's, but this has been talked about for some time no

 

[frodo1008]

I liked both of your posts here! But what I found most interesting is that (while I didn't even see your second post before I wrote my last one) we said almost the same thing here!<br /><br />Originally I was for using the already developed shuttle parts for propusion as I thought it would be less espensive. But now that I can see that doing this for either the SSME derivative OR the SRB upgrade is going to actually drive up the costs of the CEV/CALV system for going back to the moon to quite unacceptable levels (even to Griffin, who unlike O'Keife is NOT just a bean counter).<br /><br />So I too (and perhaps Griffin himself) am now beginning to start to think in terms of using the already developed parts of the EELV systems! <br /><br />Heck, for the kind of developement money that is being talked about here, they could just as well use a modernized Saturn V derivative!<br /><br />It would certainly be far less expensive to make use of the EELV technology that is already paid for with military funds (just like in the befginning of NASA) than for NASA to develope its own system!<br /><br />So I am now guessing that I was indeed incorrect in the beginning , and applogize for that! However, I can at least have the excuse that it DID look like the pure shuttle derived hardware could do the job for less at that time, but not anymore!<br /><br />However, at least it is still quite early in the develpement cycle, and NASA can make changes if necessary!

 

[radarredux]

> <i><font color="yellow">So I too (and perhaps Griffin himself) am now beginning to start to think in terms of using the already developed parts of the EELV systems!</font>/i><br /><br />At the very least, Griffin should use the threat of the EELVs as a weapon to force ATK to lower their prices.<br /><br />I also like the idea of Griffin holding out the option (at least for the CLV) to use something other than ATK's SRB just in case there is an accident. These 2-3 year down times in flight are ridiculous if America wants to get serious about being a serious spacefaring nation, as opposed to a <i>sometimes</i> spacefaring, or <i>mostly</i> spacefaring nation.</i>

 

[radarredux]

> <i><font color="yellow">However, at least it is still quite early in the develpement cycle, and NASA can make changes if necessary!</font>/i><br /><br />Amen. It is so much cheaper to change things at this point than it will be 5-6 years down the road.<br /><br />Along those lines (and my previous post), I would like to see NASA to consider alternative Lunar mission profiles that could accommodate the EELV hardware for the CaLV. For example, the current mission profile (4 people on the surface, at the poles, single LEO-rendezvous) I believe can only be met with the CaLV design.<br /><br />Could NASA develop alternative but less demanding mission profiles (e.g., 2 people on the surface near the equator) or (double LEO-rendezvous or both LEO and Lunar rendezvous) but using much of the same hardware such that alternative launch hardware could be used?<br /><br />Once again, the current plan will ground America for several years (at least for trips to the Moon) if there is a failure in a CaLV launch. Also, it forces NASA to pay potentially monopolistic prices. Having alternative approaches could provide for a more robust program and potentially keep prices down.</i>

 

[josh_simonson]

That was the plan for the EELVs for unmanned cargo, and it's not working out that way in practice. In fact they're working together to divide the work up evenly rather than competing for the work.<br /><br />What would we do if all the oil suppliers decided amongst themselves that each would make a certain percentage of the supply and not compete with eachother on prices? Oh wait, that happened and we did nothing. <img src="/images/icons/wink.gif" />

 

[gunsandrockets]

"However. I am still at this point for using the original 4 segment SRB (at least we know it to cost some $38 million per unit) along with the more powerful RS68 for the CALV. "<br /><br />Great idea! Hmm...now where did I hear about that idea before?<br />From March 24...<br /><br />http://uplink.space.com/showthreaded.php?Cat=&Board=missions&Number=470265&page=0&view=collapsed&sb=5&o=0<br /><br />

 

[gunsandrockets]

"The CaLV with RS-68's, five segment SRBs and J2X has a payload of about 18,000 pounds less than a Saturn Five. " -- SG<br /><br />I thought the Saturn V had a LEO payload of 118 tonnes. The SSME powered Aries V was supposed to have a LEO payload of 125 tonnes, and the RS-68 powered 10m diameter Aries V is supposed to have 10% better payload which would be 137 tonnes to LEO.<br /><br />

 

[gunsandrockets]

"I have just spent about half-an-hour looking for information on just how much additional weight the newly configured rocket will be able to haul to low earth orbit. "<br /><br />"Presumably it will put up more than the 125 tons that everyone had been talking about?" <br /><br />"Does anyone in these parts know exactly what a rocket with five RS-68 engines coupled to a pair of five-segment solid rocket boosters can do in terms of weight to orbit?"<br /><br />From what I was able to find, the RS-68 version of the Aries V will carry 500 tons more propellent in it's larger 10m diameter tank. That's about the mass equivalent of 2x the mass of the Earth Departure Stage. This increased propellent will supposedly improve the payload capacity by 10% (going from 125 tonnes to about 137 tonnes to LEO).<br /><br />Interestingly, even though the 10m diameter Aries V will carry more propellent, this new configuration should be quite a bit shorter than the original (shuttle-external-tank based) configuration. By my reckoning going to 10m diameter is a 43% increase in cross sectional area over the old 27.5 foot diameter tank. So even though this new configuration is planned to hold about 20% more propellent the total height of the vehicle should be shorter.

 

[gunsandrockets]

"This cost increase was due to the change from the already developed 4-segment RSRM to the 5-segment RSRM/B. This motor would have to be developed anyway for the CaLV, so it isn't a cost increase at all. Sure, it will cost some money to develop what will be the world's most powerful rocket, but the 5-segment motor allowed NASA to drop SSME, which will save billions of dollars over the life of the program."<br /><br />The plan for using SSME was a mistake and the plan for using a five-segment SRB is a mistake.<br /><br />Now that RS-68 and a larger diameter tank are in the works for the Aries V, using a five-segment SRB is no longer neccessary. And the only reason for using any Shuttle SRB for the Aries I is because of the grossly inflated mass of the CEV. If the mass of the CEV were reduced it could be launched on EELV instead.<br /><br />(And what of the 'lofting trajectories' of EELV? The problem once again is too much CEV mass. With a lighter CEV the EELV could fly a different non-'lofting trajectory' and still deliver the CEV to orbit.)<br /><br />Reducing the mass of the CEV is easy. The biggest problem is the 1.7 km/s delta vee NASA requires. The second biggest problem is the absurd 9.5 tonne mass of the CM. <br /><br />NASA has already tried to cut back the mass of the CM by reducing it's diameter to 5m, though it should go even smaller than that. The 1.7 km/s propellent load could be cut in half if NASA changed the LOR moon plan to a LPR (L-1 rendezvous) plan. In other words reducing the original 23 tonne mass of the CEV to less than 15 tonnes isn't hard.<br /><br />Even though NASA has backtracked on use of the SSME, I don't expect NASA will go to use of the EELV for the CLV. I would not be surprised at all though if NASA shrinks the size of the CEV and dumps the five-segment SRB, sticking with the four-segment SRB for both launch vehicles and thereby saving much development cost. <br />

 

[mattblack]

ATK advocates fight back for the 5-Segment:<br /><br />http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=2545&start=16&posts=22<br /><br /><br /> <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[edkyle98]

"Up till this last post you did make sense. But the last is just not as true. The developement costs for the five segment were supposedly known all along to be $1 billion! After all, they already had a four segment motor anyway. If upgrading these solids costs billions then they are just too damn expensive!"<br /><br />It can't possibly be correct that the original 5-segment estimate was only $1 billion. Thiokol told NASA in seven years ago that it would cost *at least* $1 billion to develop a five-segment-booster for shuttle. That's at least $1.2 billion today, and that was only a shuttle modification to develop a booster that worked much like the previous model. For CLV, there needs to be not just a five-segment motor, but also a new interstage with a new roll control system along with new flight control systems, new recovery systems (if they decide to use them) etc. The development and qualifcation testing program itself is going to cost mucho bucks (there are going to be several ground test articles and several flight test articles). <br /><br /> - Ed Kyle

 

[newtons_laws]

Re Mattblack's earlier post:<br /><br />"REMEDIES(?): <br /><br />1): Drop the 5-Segment SRB altogether!! Keeping them identical to the current model preserves Shuttle legacy tooling, jobs, raw thrust, and safety statistics. Also, deleting the 5-Segment will save hundreds of millions dollars and maybe 2 years development time. This might restore the ATK development figures to the original $1 billion dollar quote (or near enough to it – name me one manned space project that was on time or budget??!!) The CLV’s resulting loss in payload capability could be mostly made up by going to 2x J-2X and a bit more propellant on the Upper Stage. Also, the J-2X will have better isp and thrust than the original study baseline anyway. The new CaLV configuration will lose 4-or-5 tons in capability by losing the 5-Segment, but with an aggressive RS-68 uprating program to improve isp and thrust, not to mention restoring 2x J-2X to the Earth Departure Stage should make up most if not all of the CaLV payload capability. "<br /><br />That sounds sensible. As regards the CaLV payload capability using existing 4-segment SRBs, maybe a dumb question, but what is to stop the CaLV having 3 (or even 4!) 4-segment SRBs?<br /> <div class="Discussion_UserSignature"> </div>

 

[mattblack]

Oddly enough; the Shuttle SRBs to the best of my knowledge have never been tested as a 'short' 3-Segment. If they were then to be made this way -- there'd probably have to be costly re-certification!! Also, reducing to 3-Segments would reduce the burn time from 128 seconds to about 96, which would reduce payload and also necessitate a revised Ascent Profile.<br /><br />Hardly worth all the effort, basically. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[newtons_laws]

mattblack<br />I think you misunderstood my question - I wasn't talking about a 3 segment SRB - I was asking why the CaLV design couldn't compensate for the reduced thrust of the existing 4 segment design (compared to the expensive proposed 5 segment design) by using 3 SRBs (rather than 2).<br />Thanks <div class="Discussion_UserSignature"> </div>