2nd CLV giant problem: SINGLE 2nd stage SSME engine

josh_simonson · Dec 28, 2005

>ALL configurations MUST have the SAME "LOC" because the "LOC" of the LAS is the "LOC" of the entire rocket+crew! Nope, you're quite, flat-out wrong. If one rocket has a failure rate of 10% and another of 20%, and the LAS has success rate of 90%, for one rocked LOC is 1% and the other it's 2%. Now if you factor in that different types of rockets have different failure modes, some which might explode and damage the LAS, ect, it's quite easy to see different rockets having different LOC numbers when they use identical CEV/LAS. For these paper rockets, they know how many tanks, valves, pipes, pumps, pistons, actuators and other items there are, each has a certain reliability, so one can get a reasonable idea of a total vehicle's reliability. To a large extent they're built from existing engines and parts that have been very well characterized. SRBs are very simple, which makes them reliable, and is directly why they won out over the EELV options - a liquid fueled engine can't be made to be as reliable as an SRB due to the number of moving parts inside them. One might question the cost numbers, or more specifically the flight-rate (they claim 6/year on the HLV and that's unlikely).

gaetanomarano · Dec 28, 2005

I've already seen some info about ESAS before the draft report, I've read the articles linked in some uplink's threads and I will downolod and read (when I've the time) the full report... but I can say to you why I think it can't be a good plan (but, please, don't say to me that I judge it before read it... it's too easy!) the VSE/ESAS plan is not "make the best space plan with the best (past, to-day's and to-morrow) technology"... but... "build a plan with THESE parts to have some funds" certainly you've seen the Apollo13 movie (I've not read the Jim Lovell's book "Lost Moon" but I imagine the movie respect the reality of facts) if you've seen it (or read the book) you know the part when the mission-control director Gene Kranz give to his engineers a very important problem to solve in a few hours (the different shaped CM and LEM CO2 filters) "you must put this (the CM filter) in this (the LEM place) using only these parts..." well... the ESAS plan is the SAME! it's like NASA chiefs have said to their engineers... "you must build "a plan" (it's not important which plan) using ONLY these parts (SRB, SSME, Shuttle tanks, etc.) to give it to Congress for funds" ONLY a plan made with the BETTER to-day's and future technology may be a VERY GOOD plan a plan made with old ideas, old targets, old technologies, old designs, old procedures, old components (with some refreshing and refurbishing), without fantasy and innovation, made ONLY to recycle the Shuttle scrap & trash and have very much funds ******* CAN'T BE ******* a good plan!!!!!!!!!! ("by design"...) a good plan must be made with better ideas and parts, not with the old scrap-iron in the NASA garage!

kdavis007 · Dec 28, 2005

Yawn!!!

dobbins · Dec 28, 2005

That pretty much proved SDC is more interested in ad hits than anything else.

josh_simonson · Dec 28, 2005

>...............................without fantasy....................... Okay, let's throw the Olsen twins into ESAS and call it even then. <img src="/images/icons/wink.gif" />

gaetanomarano · Dec 28, 2005

I'm not wrong and I don't agree with your post if the LAS will REALLY have a "success rate" of (only) 90%, I can only suggest NASA to stop ALL flights or fly only with helium ballons... to do its job, the LAS must be VERY FAST and VERY RELIABLE acting in fractions of seconds to be FASTER of the FASTEST problem that may happen the "in line" design of rocket and capsule helps VERY MUCH the LAS to be sufficiently fast and realiable to save the crew 99.99% of times this becasue the most dangerous problem may happen where there is the "fire" in all (liquid or solid) rockets the "fire" is at bottom and the LAS is on the top and the fire need time to arrive to the LAS... not so much time but much more than those the LAS need to save the crew so, if the LAS (as I hope) will have a success of 1 in 1000 or better, the CLV design may have TWICE the safety than predicted in the chart (the LAS safety or more) but also the other rockets will have the same LOC only if the rocket is safer than LAS their LOCs may be different but this is impossible since the LAS is made to be much faster and safer than any possible rocket (if the LASA is designed to save the crew and not only to be the star on the top of a Christmas' tree...) you've used the right words... "paper rockets"... they are ALL "paper rockets" and no one can give exact figures about the reliability of "paper rockets"... only REAL flights may give REAL figures!

gaetanomarano · Dec 28, 2005

the new moon missions and vehicles are an exact (xerox)copy of the (original) apollo missions... we don't need the Grimm's brothers to give a bit of fantasy to this "grey plan"...

strandedonearth · Dec 28, 2005

Josh was only doing what you do so often, gaet: using hypothetical numbers pulled out of thin air as examples, simply to demonstrate the math. Plug in your own numbers, the basic principle behind his math remains the same. You never admit when you are wrong, (and you are often wrong) even when it is pointed out to you. Which pretty much means you are a crackpot. And even you should be able to grasp the difference between LOC and LOM. LOM means the crew was saved, but the mission has failed, due to a malfunction in the vehicle. The ET is not faulty. The only reason the ET caused a Loss-of-Vehicle is because there was a fragile TPS in the path of falling foam. The proposed vehicles don't have anything in the path of falling debris, so there is no danger from that source.

gaetanomarano · Dec 28, 2005

I understand the diference... but rockets reliability (this is the argument of that posts) is close to LOM because the rocket can't fly (or have no reasons to fly) without the crew (as I've explained in my post) about my threads... I give only my opinion and point some problems or suggestion... if some like (or apply) them, I'm happy... but, if no one will like or agree or apply my proposals, I don't cry for this... I don't risk my life or my money if a rocket is bad designed

strandedonearth · Dec 29, 2005

But will you ever admit you are wrong about something? It doesn't appear so.

josh_simonson · Dec 29, 2005

>you've used the right words... "paper rockets"... they are ALL "paper rockets" and no one can give exact figures about the reliability of "paper rockets"... only REAL flights may give REAL figures! So in your world one must fly the rocket back to back 1000 times to verify it is safe before sending up a payload or people? Sure you can't account for everything in calculating the things reliability, but you can get close. How do you think insurance companies decide the premiums for launch vehicles that haven't launched enough times to have statistical significance? There is an entire profession of people that do this for a living, they are called actuaries. Since these rockets all use flight proven engines (and about 1/2 of all rocket failures are due to engine failure, historically) you've got a pretty good idea of how reliable the most risky part is. To put it another way, we're building a car from the parts of a few other cars. Do we want to drop in the engine from a yugo or from a honda? Though this car is a paper car, we can be pretty darn sure that the one with the yugo engine is going to be less reliable than the one with the honda engine. Anyway, the flight manifest calls for 30 iss and test launches before any moon missions begin (most un-manned) so the CLV will be shook down pretty well before primetime.

najab · Dec 29, 2005

...my first suggestion is to build a 10-12 ton CEV and launch it with the best (under NASA evaluation, of course) ready available mid-rocket... You still haven't said what 'ready available' rocket it is you plan to use.

SpaceKiwi · Dec 29, 2005

<blockquote>In reply to:<hr />But will you ever admit you are wrong about something? It doesn't appear so.<hr /></blockquote> It would not appear so in 1108 posts thus far. I would like to attribute this to 'language difficulties', but that would be naive on my part I guess. I'm not sure the real benefit he gets from all these threads. Support for his viewpoints is minimal at best, and he doesn't appear willing to incorporate anything offered up in rebuttal into his thinking. He spends an extraordinary amount of time responding to most every counter-thought when it is clear his own views are well entrenched and, therefore, not subject to the normal 'validation' issues others of us might have when we offer our thoughts up for forum discussion. Bizarre. <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

propforce · Dec 29, 2005

*Sigh* I don't I am gonna get a straight answer out of Gaetano... <blockquote>In reply to:<hr /> Gaet: "... the earth-start version was tested 300+ times in TRUE launches, while the new version and its reliability are completely unknown .......... consider that, the "never long-tested" (not 300+ times like the earth-start version) "air-start" SSME, may fails in 8%, 12%, 20% or more CEV/CLV flights... " Prop: "...Do you know the differences in engine operating characteristics between "earth start" and "air start" ??? " Gaet: ".... not exactly... it may need an ignition-system (now on earth) that fly with the engines... but what impressed me is the fact that SSME's manufacturer will need three years to modify the engine... then, it is not a "minor change" ..." Shuttle_Guy: ".... Even a minor change means a recertification program that takes time. ..." Prop: ".... Suppose you 'design' so that the thrust of each engine alone will get the CEV to orbit the, if both engine work as expected, you'll have to require engine can throttle to 50% of its power at the beginning of the burn, and down as much as to 20% near at end of burn. This is beyond the technology level of today's liquid rocket engines. So you'd spend another billions of $$$ with another 10+ years of delay before launching CLV?..." Gaet: "... I suggest a four/five little engines' design for 2nd stage with 120-130% thrust, so, they will work around 80% of its max thrust in normal flights... not 50% ..." Prop: "...That means another engine development program with another 4~5 years of delay. ..." Gaet: ".... suggest to use four/five ALREADY available engines for 2nd stage (NASA may choice the better engine for that purpose) .." Prop: "... WHICH engine that is ALREADY BUILT ????? ..." Gaet:"... do you know that in the world there are dozens of different (working) rockets and AL</blockquote> <div class="Discussion_UserSignature"> </div>

josh_simonson · Dec 29, 2005

>You still haven't said what 'ready available' rocket it is you plan to use. He clearly (from the vast tome of gatoganda) believes the long march and soyuz rockets are the 10-12 ton 'commonly available' vehicles. He'll probably suggest the taepodong too. <img src="/images/icons/wink.gif" />

mattblack · Dec 29, 2005

The ONLY possible alternative to the single SSME would be 2x J2S: Slightly higher thrust and lower engine weight (even with 2x J2S), airstart capability already there, but lower ISP and bigger size of 2x to squeeze within the stage interface. See attached picture for size comparison of J2 versus the F1: An SSME is about halfway between a J2 and an F1 in size. <div class="Discussion_UserSignature"> One Percent of Federal Funding For Space: America CAN Afford it!! LEO is a Prison -- It's time for a JAILBREAK!! </div>

gaetanomarano · Dec 29, 2005

it's very strange and incredible... the main effort of some users here appear ONLY to demontsrate that other users (like me) are "wrong"... and NOT that the CEV, CLV, SRB, etc. are "right" (and safe, cheap, good design, etc.) I think that if NASA build a better CEV/CLV (or Russia build a better Kliper, or China build a better Shenzhou) this may be "bad" for some uplink's users but may be very good for the astronauts that will fly with them...

gaetanomarano · Dec 29, 2005

fly the rocket back to back 1000 times >>>>> no, but it must fly a few times to know its flights records and comparison between different rockets can be made only with real flights experts can try to "evaluate" the realiability of unexisting rockets (and compare them) but we can't accept them as "THE TRUTH" and base on them vital choices because in REAL flights they may be COMPLETELY DIFFERENT sending up a payload or people? />>>>> we can risk a payload (it's only money)... for people they (first) need a good LAS and (second) to be lucky insurance companies decide the premiums for launch vehicles />>>>> this is not so complex because they have the cost of the rocket/payload and past rockets launches' statistics... also, if their calculations are wrong (as many times really happen...), they only save or lose money... not crews' lifes these rockets all use flight proven engines />>>>> we are talking of the 2nd stage here, that NASA have already decided to be with a liquid engine, the difference to design it with many little engines and 130% total thrust is: save money... save time... increase the reliability and success of flights yugo or from a honda />>>>> I don't know the "yugo" but a single (and modifyied) SSME for 2nd stage appear to me a "yugo choice" for 30 iss and test launches />>>>> I've read of a very few (very expensive) tests before first manned flight... about ISS flights... they can't be "tests" (the life of ISS' astronauts is less important of the life of the next moonwalkers' star?)

SpaceKiwi · Dec 29, 2005

Nice graphic, matt. That F-1 is a thing of beauty, and appropriately named (for followers of Formula One). <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

gaetanomarano · Dec 29, 2005

you can: 1. see the mattblack post 2. search yourself an engine that meet the specs (four/five engines, same total SSME thrust + 30%, less the reduced thrust needed if the CEV/SM will be 12 tons instead of 23) 3. wait me when I've an exact design and exact figures

gaetanomarano · Dec 29, 2005

1. I can't propose "engines" only to have critics... 2. probably ALL other engines are "not qualified" but qualify four little engines is like qualify the single SSME as 2nd stage engine 3. since NASA have used the Shuttles for crews, now only Russia and China have rockets/engines to launch crew (this is due to NASA mistakes not to me...) so that job must be made in next years 4. the choice of four/five engine (with extra-max-thrust) is CLEARLY better for reliability (and to save money and missions) 5. I can give (and I will give) "my" design of a 4/5 engines stage, but NEVER it may be better than a design made by NASA! ...so, why do you want (NOW!!!) "my" choice of engines? ...ask NASA about your post... please read this: http://uplink.space.com/showthreaded.php?Cat=&Board=missions&Number=415290&page=0&view=collapsed&sb=5&o=1&vc=1

gaetanomarano · Dec 29, 2005

no, I suggest to use american engines for NASA choice... but, unfortunately, your claim is true... only Russia and China have (now) rockets for crews (in fact, NASA rents them to send in orbit its astronauts...)

strandedonearth · Dec 29, 2005

Actually, it's not like I'm trying to prove you wrong in general. I can accept that the CLV may not be the best choice. But it's also my opinion that it's not a bad, drastically flawed choice as you seem to think, for many reasons which I and others have tried to explain. It would go a long way to establishing some credibility on your part, however, if once in a while, you could post something like "thank you, I was mistaken" when your basic "facts" have been corrected. Little things like the fact that lift-off, not main engine (SSME) start, occurs at T-0. Amongst many others. That's what I would like to see. Just a simple "I stand corrected" instead of ignoring when you've been corrected

gaetanomarano · Dec 29, 2005

bad, drastically flawed choice as you seem to think />>>>> no, it's one of many possible designs, and it can work... but (as you say) it's not perfect, so, may be changed to be better (like near ALL things in the world) T-0 />>>>> read my posts... I've accepted the correction and changed my claim (if T-0 is the SRB ignition and Shuttle lift-off, the only moment to stop engines may be before T-0)

carp · Dec 29, 2005

Gaetano said:"if you really believe in these charts, you're too smart (as a contractors' PR man...) or (sorry) VERY INGENUOUS"!!! __________________NO,we believe only in to the words of Gaetano Martino,the modern genius of astronautics science.NASA can mistake,Gaetano the great,NEVER!

2nd CLV giant problem: SINGLE 2nd stage SSME engine

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