Do you (exactly) know how to "man-rate" a rocket?

gaetanomarano · 2006-05-08 08:38:38

I should have put in that these are the forum discussion here on Newmars for the links.
A lot of ground has been discussed on why EELV's would need to be redone to make them man compatible.

thank you for the links

about the EELVs... I think you're right but...

1. the costs (and time!) to redesign a ready available mid-rocket can't be so high like build from zero the new CLV

2. after redesign the cost of a mid-rocket + 4xCEV + SM-light for ISS missions will still be incredibly low if compared with a CLV+CEV+fullSM

3. my "first choice" is to don't build any new rocket, but only an SLV for moon missions and use the ready available vehicles for ISS

SpaceNut · 2006-05-08 08:56:31

I think that some acronyms need defining.

CLV is the crew launch vehicle of which the CEV is the upper stage of this transport system.

CaLV is the cargo launch vehicle or what I think you are calling fullSM or SM-light for ISS missions. The CaLV has the ability for large cargo hauling to the ISS or to have the trans stage and lunar module for moon flight. Basically shutlle stack less orbitor with new upper stages.

gaetanomarano · 2006-05-08 10:16:52

The CaLV has the ability for large cargo hauling to the ISS

unfortunately the CaLV can't do the same job of the Shuttle for ISS because its payload will be giant but "stupid", without any navigation systems and engines

the navigation system is the most critic part to design (the DART has failed and the ATV was delayed)

to-date, only Russia has a big experience in orbital navigation system of capsules and cargo like the Progress (in fact, Japan, China and ESA have used or will use the russian technology and know-how for their orbital vehicles)

another problem with the CaLV, used as ISS cargo like with Progress, is that 60%+ of the payload's weight will be for cargo-vehicle, engines and fuel, then, a 125 tons CaLV can deliver about 50 tons NET of cargo to the ISS, much more than the 2.4 tons of a Progress but with an higher cost per ton

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

since the thread was changed from "man-rate rockets" to EELVs, I wish to tell you the full story of my article about the SLV and of this thread (since I'm still interested to know something more about "man-rating")

last december I've made some posts on a forum about the high risks to fail of the VSE "one-and-half" launch architecture, but only in April 12 I've written and published the article about the SLV on my website

after publishing the article, I've posted the link on a few space-forums and space-blogs and I've sent also an email to space experts of some newspapers and space-websites

in April 15 I've sent an email with the link to some addresses including a famous space-website: http://usspacenews.com/

in April 16 I've read on usspacenews this article:

CEV Update
April 16, 2006
This coming week is a time of decision for the CEV/CLV .................................
..............................................................................................................
......................................................................................................
........................................................................................................
..............................................................................................................
...........................................................................................................
.....................................................................................................
..................................................................... One more idea from this week
you might find interesting. Cancel the CLV and man rate the HLV. That will most likely not
happen. It should, saves a ton of cash and gets us to one design. Two
SRB's, one on each side of the new upperstage. Looks a lot like the Shuttle C concept with the
CEV on top. Could happen. Solves the energy problem. But, it's not Monday yet.
Lastly the ISS CEV will have very small version of the SM (sort of a limited propulsion module).

(unfortunately, in the article there is no link to my article nor info about the source nor info/link about a different source ...if the "idea of the week" was suggested the same day of my article/email but on another website or newspaper...)

well, since I don't know how rockets/engines can be "man-rated" (and how much time and money may cost) I've decided to open a thread on a space-forum (this) to know something more about that procedure, to prevent the (possible) main critic against my proposal: the time, costs and problems to "man-rate" the SLV-CaLV (as explained in my first post of this thread)

but ONLY about man-rate an SLV for moon missions NOT to man-rate any EELV since I think that an orbital-CEV for ISS is very expensive and completely unnecessary with the great choice of crew and cargo orbital vehicles that will be available in the next decade

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SpaceNut · 2006-05-08 11:02:14

unfortunately the CaLV can't do the same job of the Shuttle for ISS because its payload will be giant but "stupid", without any navigation systems and engines

Quite right that if it can not for other reasons as well such as the modules needing to be craddled to protect them.

the navigation system is the most critic part to design (the DART has failed and the ATV was delayed)

But though it failed it will get fixed since the problem for failure was identified in that the GPS signals had to much back ground noise.

another problem with the CaLV, used as ISS cargo like with Progress, is that 60%+ of the payload's weight will be for cargo-vehicle, engines and fuel, then, a 125 tons CaLV can deliver about 50 tons

Actually the orbitor weighs about 100 mT and can bring to orbit on the 4 segment stack at least 25 mT more, so the stack has the capability with the 5 segment to lift with a new upper stage the 125 mT.

well, since I don't know how rockets/engines can be "man-rated" (and how much time and money may cost) I've decided to open a thread on a space-forum (this) to know something more about that problem

This is all about the testing and design perameter verification to make an engine for manned use. The other way around the issue is to use engines and other items that are already in use. Hence this is the direction that Nasa has gone is to lower the cost and time to get to orbit and beyound.

Sorry gaetanomarano that your research article has been ripped off, that is more the fault of todays society...

gaetanomarano · 2006-05-08 11:43:40

the modules needing to be craddled to protect them.

true, the cradle is an extra weight, but also the automated-cargo by itself

the Progress weights 8 tons but only 2.4 are of usable ISS payload

the ATV will be bigger than Progress but with similar vehicle/payload rate, then, a "CaLV-Progress" will have 75 tons of engines, cradle, protection, structure, fuel, etc. and only 50 tons of net payload, modules, resupply, etc., like two Shuttle launches to LEO or three-four to ISS

but the main problem of the CaLV for cargo is not its high price (since 99% of its value is expendable) nor its payload, but its TIMELINE

The first test launch of the CaLV is planned for 2017 (+ delays) and the first units will be used for the moon missions (that is its main purpose)

probably the first module sent to the ISS with a CaLV will fly after 2020...

then, the CaLV can't be used for the ISS simply because in the next 15 years it WILL NOT EXIST!!!

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SpaceNut · 2006-05-08 21:13:46

More wishy washy nasa decision making at work...

CEV landing system re-evaluated all because of the possible abort over the atlantic ocean.

GCNRevenger · 2006-05-08 22:35:29

Okay, now that I have a little time to write...:

"true, but it must be close to about 99%

also the risks of the LAS itself are true, in fact the CEV/CLV can't be "10 times safer" than Shuttles (NASA claim) but probably will have the same risk (we can know the real figure and compare it only when the CEV will fly 114+ times)"

No. There are many ways to abort the mission without resorting to the dangerous escape system, it would obviously be preferred just to gently push off from the booster and land normally before reaching orbit. Or better yet, burn the extra fuel and go on to orbit so you can complete your mission or at least reenter at the location of choice.

The escape system has a 0% chance of saving the crew if you ignore the factors and conditions concerning its use. Infact, the current plan for the CEV is to jettison the escape system before reaching orbit, because its too dangerous to use at high hypersonic speed.

And what in the hell are you talking about? It will absolutely be far, far safer then Shuttle, Shuttle has no real abort options at all nor does it have an escape system except parachutes. It has no engine-out capability, its heat shield can be broken chunks of styrafoam, and is easily ten times more complex then the CLV/CEV will ever be. Its just common sense, there is less to go wrong on the CLV/CEV, so it will be safer. Your statement is VERY dumb.

"not true, this is only an (undemonstrated) myth"

Wrong, the Atlantis actually sufferd a minor booster burnthrough, which was facing away from the vehicle. And what happend? Nothing. The mission suceeded just fine. Since the CEV will be on top rather than beside the booster, a burnthrough simply can't damage the rest of the vehicle.

"the realty is that both rockets will have risky and safe moments in their flights"

Now you are just jibbering. The reality is that the CEV/CLV combo will have much less risk, because the CLV is inherintly less dangerous to ride on, and the extra CEV fuel adds maneuverability other designs lack.

"The lower reliability of the big CaLV or the EELVs with its eight engines or their 6-8 cheap failure-prone satellite launcher engines is compounded with the fact that they don't have these above "softer" failure modes for very long during acent, since they accelerate more slowly.

lower reliability.... absolutely not true"

Yes the big CaLV will have partial engine-out ability, but this is counteracted by simply having lots of engines. There is a small chance that when a turbopump engine, like the RS-68, fails it will explode and destroy the rocket. In such an explosion, the chances that the crew survives, escape system or no, are not good. The CaLV will need all its engines to fire for liftoff and the first minute or two so your vaunted engine-out doesn't exsist then. And if any of the 2, 3, or 4 SRBs fail the mission is over. And since the whole rocket accelerates slowly, it increases the time you must rely on the dangerous escape system even if the engines don't explode. And again, the RS-68 was never built for realibility, it was built to be CHEAP so it is more likly to fail in the first place.

And here is a real biggie, the crew will be riding on a rocket with the huge fuel tank right next to the huge booster rockets: Didn't Challenger teach you anything? Not to put the crew on a vehicle that combines big segmented solid rockets beside tanks of liquid fuel! If the boosters leak in the CLV, nothing happens, but if they leak on the CaLV you risk a catastrophic explosion like Challenger again. Even worse since the CaLV will carry even more liquid fuel.

The EELVs are not any better. None of the medium models could lift even a mini-CEV without using those infernal little solid rockets, which have doomed several Delta launches and are all-around unpredictable. This is seperate and in addition to the other failings of the EELVs with their lack of instrumentation and slow acent.

"Shuttles' failure at lift-off was due to an SRB fault!!!"

Wrong again! The failure was due to using the SRB out of its design specification, and from the booster burning a hole in the external tank. If there were no tank next to the SRB, the little leak in the booster would not have caused the explosion either.

"but we must wait to have all answers to our doubts"

Again, no. We don't have to wait and see, because we can already calculate the risk right now with very good accuracy. You don't seem to have much of a grasp of engineering at all.

"are safer and more reliable than single engines because, if one engine fails... the other rockets' thrust can do the full job"

Wrong again! Its only safer if the engine shuts down, instead of explodes and takes the whole back of your rocket with it. And at the moment of liftoff and for the first minute or so, all the engines have to fire. And if either one of the 2+ SRBs fail, the mission is over. Good thing the CLV only has one.

Nor does Soyuz have dozens of engines. The first stage has five turbines, just with multiple chambers each. The worst of both worlds, it just lets you get away with sturdier chambers.

more later

GCNRevenger · 2006-05-08 23:02:41

"no, NASA plans may simply have mistakes, like all "plans""

Stop trying to mince words, you are bad at it gaetano. You state that the chance of each sucess is extremely low with the NASA plan, so that means its unworkable, not a "mistake." Since you think its unworkable, but NASA thinks it is, that probably means you are wrong since NASA is much better at spaceflight then you are.

"The Shuttle and ISS were mistakes, but they were mistakes based on the desire to maintain the political status quo, and were not the product of engineering decisions. The ESAS plan is largely founded on engineering, so either the engineers are right or they are wrong, Shuttle and the ISS were a different kind of mistake.

I don't agree"

History is not a matter of opinion, and "opinions" to the contrary of the facts of history are lies. The Shuttle was indeed built to keep NASA engineers in business, not to accomplish anything useful, or else its designers would have never allowed such a bad vehicle to be built. Its that simple, too bad you can't understand that.

"true, but the lift-off (with so much fire and the tanks full of fuel) is very dangerous"

Yes. And the CaLV with the loaded EDS and LSAM stages right behind your capsule would make a MUCH bigger explosion then the CLV's smaller upper stage. And with so many more engines, there are more things to blow up and ignite these fuel tanks on the CaLV, increasing risk.

"to-day's SRB is safe but CLV's SRB will be different and the entire CLV/SM/CEV system will be very complex"

Again, more ignorance, and biased ignorance at that. You complain about the little two-engine CLV being unsafe because its "complex," well what about the huge, slow, eight engine CaLV?

"we must know the (real) reliability of the entire system, not only part of it, and the full system will be "new and experimental" because there are thousands of (big and little) parts that may work or not

a new car my be perfect but the accident may happen due to a defective wheel...

...to have REAL statistics of its reliability (and we need 250+ successful flights to claim that the new CLV is "safe"

When are you going to stop saying dumb things that aren't true, gaetano? We already know that the engines will be reliable because we've already seen them, the SRB and the J-2 are well developed engines. And its a simple principle of engineering that ground testing can accuratly estimate the reliability of a particular system, we are pretty good at doing that now.

" The RS-68 has no good emergency shutdown modes

I hope that NASA will use the SSME"

NASA isn't, the RS-68 has recently been chosen for the CaLV, so the SSME program and assembly lines will be closed perminantly when Shuttle is gone. The SSME is very reliable and efficient, but it also lacks thrust and operates at very high pressure, so if it fails it tends to explode in a big way versus other engines. It is also ruinously expensive, and there is no reason to use such an engine on a heavy rocket when you can put people on a seperate safer purpose-built rocket like the CLV.

"please avoid personal opinions about me, thank you"

I will form opinions of you as I see fit, and so far what I have seen of you indicates that you are ignorant, unobjective, and unwise.

gaetanomarano · 2006-05-09 06:03:44

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The escape system has a 0% chance...
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this verbal contrast is a non-sense, in the first part of the flight the astronauts life is 100% in LAS' hands, in the second part of the flight it is 0% (because the LAS is jettisoned...)

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It will absolutely be far, far safer then Shuttle...
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true at Shuttles' lift-off and part of the flight, not for the entire Shuttle flight

however... we need to see 112 successful CEV launch to make a true comparison...

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Now you are just jibbering
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please avoid personal attacks, thank you

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The reality is that the CEV/CLV combo will have much less risk...
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the (old!) SaturnV-SLV was 100% successful, the Shuttle-SLV is 112 times successful

we will see the real 1.5 launch reliability... (but I don't believe it will be so good)

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And if any of the 2, 3, or 4 SRBs fail the mission is over....
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all single-launch missions may fail due to system problem, the 1.5 l.a. may fail ALSO for hundreds stupid reasons that will make a big "sum of delays"

the 1.5 launch will BORN with "failure-option" BUILT-IN

the 3SSME+2SRB Shuttle-SLV was 112 times successful, the 11-engines (very old!) SaturnV-SLV was 100% successful

NASA is able to build a safe SLV (that will not have any "sum of delays failure option" built-in)

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Didn't Challenger teach you anything? Not to put the crew on a vehicle that combines big segmented solid rockets beside tanks of liquid fuel!
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really absurd claim!

the (NEW) side-mount-CaLV (or SLV) will fly only 12 times on the next 20 years while the (OLD and DANGEROUS) side-mount-Shuttle will still fly (as planned) 17-19 times in the next 5 years

if the risk of an SRB leak exist, why launch the old Shuttle 50% more times than a (manned or unmanned) CaLV???

also, if the SRB's leak is possible with the CLV that may don't mean a crew risk but mean a further reason of possible mission fail!

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None of the medium models could lift even a mini-CEV...
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I suggest to don't build any orbital-ISS-CEV

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"Shuttles' failure at lift-off was due to an SRB fault!!!"
Wrong again! The failure was due to using the SRB out of its design specification...
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then, if the SRB is used for the SLV "within its specs" it (and the SLV) is completely safe!

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If there were no tank next to the SRB, the little leak in the booster would not have caused the explosion either
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absurd claim, it's like say "if the airplanes don't fly never crash!"

the shuttles' tank is side mounted with the SRB but if the SRB don't have leaks the tank don't explode!

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we can already calculate the risk right now with very good accuracy...
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like with the shuttles' foam?

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You don't seem to have much of a grasp of engineering at all
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please avoid personal attaks, thank you

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Wrong again! Its only safer if the engine shuts down, instead of explodes...
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true if the engine explodes, not true if one engine will fail and the other engines have sufficient thrust (like with apollo13's 2nd stage of saturnV)

more later

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gaetanomarano · 2006-05-09 07:02:55

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Stop trying to mince words, you are bad at it gaetano...
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if you want my answers to your posts stop personal attaks

either if you are a space-enthusiast and ATK-fan or a NASA/contractors engineer/employee/official/PRman (or you hope to be), you can discuss about these arguments in a civil manner

I don't attack you, then please don't attack me, thank you

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that means its unworkable....
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I say that the 1.5 l.a. will give to all moon missions a very high risk to fail, nothing else

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The ESAS plan is largely founded on engineering...
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the ESAS plan is mainly (and largerly) founded on political decision to give contracts to the soon retired Shuttle manufactures and save their work force (and I agree with the social aspect of this decision), but, sorry, it don't have any new engineering or ideas built-in

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The Shuttle was indeed built to keep NASA engineers in business, not to accomplish anything useful....
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not true, with the same funds (and work force) NASA and contractors can work to build dozens of useful space-things

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make a MUCH bigger explosion then the CLV's smaller upper stage...
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not true, the astronauts may die with a big or a little explosion

NASA can build a safe SLV like the SaturnV or use an 1.5 l.a. with very high risks of missions' failure "buil-in"

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Again, more ignorance, and biased ignorance at that
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please avoid personal attaks, thank you

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CLV being unsafe because its complex
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I can't know how much it will be safe or not, but it will be new and complex, then, may have hundreds little and big DELAYS (or failures) due to hundreds unknown reasons

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When are you going to stop saying dumb things that aren't true, gaetano?
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please avoid personal attaks, thank you

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We already know that the engines will be reliable because we've already seen them....
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all parts must work together in complex system like a new rocket or capsule

we can't say now how much the full system will be reliable without try it with REAL flights

now we can only speculate about its reliability or give our opinions

of course, I hope that it will be reliable

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NASA isn't, the RS-68 has recently been chosen for the CaLV....
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I know, it's a NASA problem

my suggestion to use the SSME is for a manned SLV

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there is no reason to use such an engine on a heavy rocket....
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only the risk to lose giant quantities of hardware and money...

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ignorant, unobjective, and unwise
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please read your sentence looking in a mirror, thank you

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GCNRevenger · 2006-05-09 08:27:52

I don't think you have a very good grasp of the concepts of reliability or spacecraft efficiency, gaetano. Two seperate capsules have twice the chance of failure, and two smaller vehicles of half the volume of a larger one will combined weigh far more then larger one.

"not true, if a single rescue-capsule fails, six astronauts dies, with two or more capsules the chance to live double, triple, etc. since, for probability's law, not all can fail at the same moment (only for murphy's law they can...)

the 4-seats capsule don't need to be big or little, simply "standardized" to save costs... if you build a 6x capsule and use it 99% of times for 4 astronauts the costs are high... if you build a 4x (for 99% of missions) and use TWO of them when you need 6+ astronauts you save a GIANT quantity of money (not only for a lower cost capsule but also a cheper SM and launcher!)

Also the ISS for six will have sufficient docking ports for MANY rescue-Soyuz, rescue-4xCEV and (maybe) rescue-Shenzhou... NASA can accomplish its rescue mission with two 4xCEV... no need of a big 6xCEV

When are you going to stop saying dumb things, gaetano?

What in the hell are you talking about, saving only half the crew of a Mars mission? How barbaric! I'm horrified that you would even think that way!

And you keep on posting dumb words about how the four-seat and six-seat capsules will be so radically different, when I have already explained to you that the four-seat will be used for long periods for Lunar transit but the six-seat only for short periods for return. The four-seat model should be big enough to put on a bulky full sized space suit, while the six-seat only needs flight suits too. They will be the same size! And finally, you consistantly ignore the simple engineering concept of the cube/square law, which dictates that the slightly larger CEV will not be much heavier then a scaled down one. Read it or shut up. http://en.wikipedia.org/wiki/Square-cube_law

NASA is also obliged by international treaty to provide a safe means of escape for ALL the ISS crew if memory serves, which means six men. It is also safer to use only one escape vehicle instead of several, because the chances are much lower one capsule will fail compared to multiple. This means six seats, and so NASA can indeed save money by standardizing, but standardize on the six-seat model!

"do you remember the dimensions and weight of 15 years ago PCs, cellulars, etc.?

well, compare them with to-day's hi-tech stuffs and you can imagine the technology of 2020!

I think that also the spacesuits of 2020 will be incredibly new, advanced and lightweight!

If you think this, then you are even more ignorant then I thought. First of all, NASA will need space suits for the Moon by about 2015 so they can be well tested and trained with, since Lunar missions should start in ~2018. Thats really not as long as it sounds, space suit technology has been very slow in progressing.

Why are space suits bulky? Because they operate by air pressure, and so if the astronaut is to have any mobility then the suit has to be a little bit larger then the wearer. In addition, they require thick layers of tough shielding to avoid being punctured, makes them even bigger. Also, they require oxygen tanks, nitrogen tanks, water tanks, and batteries. None of these things can be reduced in size much, since the higher the tank pressure the more dangerous. Since you can't make people smaller or require less supplies, then full size pressure suits aren't going to be much smaller either.

"the (cost of) "extra-tons" is related to the 80% extra-fuel and extra-SM weight of an orbital-CEV made like a lunar-CEV

I suggest to don't build any orbital-CEV or to build a 4xCEV with an SM-light

the cost of a 20-tons and a 25-tons CLV may be similar, BOTH VERY HIGH ...then I suggest to build a 4xCEV and an SM-light with a total weight of 10-12 tons to be launched with ready available low cost rockets (after man-rate them)

You really don't seem to know much about spaceflight do you? The cost of the rocket fuel is so small compared to the cost of the vehicle, that its basically nil. If you said this to a NASA exec, you'd be laughed at, come to think of it I laugh at you too. I do agree though, don't built an orbit-only CEV with a half-sized service module. Just use the Lunar one for both roles, the savings of only building one vehicle will waaay overcome the extra fuel cost.

You are STILL not listening to me about the CLV. It will not be a brand new rocket built from scratch. It will not. The engines will be modifications of old ones, the aerodynamics basically the same as Apollo, even the avionics will be off-the-shelf. The EELVs were never intended to carry humans, they have no escape system sensors, they have few abort options, and they all use the dangerous little pint-sized SRMs. Infact, the Delta-IV would probably need six of them. It also has a large liquid-fueled first stage with engines designed to be cheap, not safe, and the whole rocket has low acceleration. It will not cost lots more to build the CLV, since the EELVs would require such extensive changes and testing plus it will be safer too, especially with the difficulty of detecting a fuel fire fast enough to trigger the escape system... Oh, and the CLV will have nearly double the payload too.

"the real costs of a CLV hardware are difficult to know now, but the early prices was around... 40M for the SRB, 60M for the SSME +2nd stage tanks +the new hardware/software to fly the SRB alone (maybe 40M) that match (only as hardware NOT with the shared CLV R&D extra-costs!) the cost of a mid-rocket (150-200M)

the new will 5-seg SRB will cost $2+ billions only of extra-R&D costs (see the recent news) that will DOUBLE or more the unit price of the 1st stage

about the J2X... it will be a new version that need time, money, R&D, tests... maybe $40-50M at to-day's prices"

Now you are just being willfully ignorant. The "real costs" are not that difficult to know, because we already know how much the parent engines cost. And as I have said before, NASA is going to develop these engines for the CaLV anyway, so actually NASA saves money by not modifying the SSME. The decision has already been made, that the CaLV will have only two SRBs and only one upper stage engine, so then you have to have the big five-segment SRB and the more powerful J-2X. But neither of these are complex engines, they are fairly simple, the J-2 is not really much complex then its little brother the RL-10. The RL-10 sells for about $5M a copy tops. The simplicity of the engine means it won't cost that much... You didn't address this. You didn't even try to address it. You just picked a scarry number out of thin air to make J-2 look as bad as SSME. Address this in your reply to this post or shut up.

"the orbital SM can't be 5 times light (because there are the engines, life support and other systems) but may be 60% lighter, that means less tons...

...see the problem in the invese way... the 3x Soyuz (that works well for ISS) weight 8 tons, then, an hypothetical "4xSoyuz" may weight (8/3)x4=10.6 tons, then, an orbital-CEV may weight 10-12 tons max ...simple!

That fact about the "CEV lite" is actually an argument in favor of the bigger CEV/CLV combo, because NASA is going to build the CLV and not put astronauts on the EELVs.

Simple? Yes, simply stupid. This is exactly what the cube/square law says is not true! If you aren't going to bother to learn anything and speak from at least a position of minimal understanding, you should shut up and find something else to talk about.

"when the Shuttle will be retired, all ISS science will be very poor (without heavy science hardware)

a 4x or 6x or 10x CEV can't change NOTHING, the 6xISS can live and work with twice Soyuz/Shenzhou launches (or 4xCEVs) and the new ATV"

You contradict yourself even between two lines! You are such a bad debater that I am probably just wasting my time writing this! If the ISS can't do anything without Shuttle, but it CAN with multiple capsule/ATV flights, then you aren't making any sense at all! If the ISS does need heavier cargo to do anything useful, then the dinky Progress and Shenzou capsules can't lift it. They are just too small. The ATVs are too difficult to build (witness the delays thus far). Which that leaves the CEV capsule, which if it is the little light-weight model can't carry any more then Progress can, so it absolutely should be the bigger Lunar model for cargo.

"the cost of the fuel is very low, but launch it (its weight + tank weight) is costly

where is the contradiction?"

Because its not true. Fuel tanks are pretty cheap, and making a slightly larger fuel tank costs almost nothing compared to a slightly smaller one. Infact, it will cost more to have two seperate assembly lines for big and small service modules then it would to build only the bigger one. And they will be on the same launch vehicle, so no money will be saved there either.

"we can't know it exactly, but a 4x CEV may weight less and many new technologies will be available only in the next 15 years"

There you go again with stupid statements. The cube/square law will apply reguardless what technology is used, and the fact still remains that the four-seat capsule large enough to accomodate a crew for a week or two will be the same size as one that is six seats for only a day. And again with the technologies, waving a magic wand to make your little capsule lighter by relying on things that don't exsist is not an argument, and infact the same technologies applied to a larger capsule will yeild a greater decrease in mass.

"absurd, it's like evaluate the reliability of a new car from the reliability of its parts

many of the NEW parts of the CLV will be the most CRITIC

we must wait, the CLV (real) reliability must be known only when REAL rockets will fly"

Now you are just being stupid, you don't know anything about real engineering. Absolutely you can predict the aproximate reliability based on the collective failure modes of its parts. Otherwise, jet airliners would be so hard to design, nobody could afford to do them.

"my "first choice" (see my article) is for "resized" moon missions that need only a 100-110 tons SLV with 4-seg. SRB"

Your "Plan C" involves direct flight to the Moon, which incurs a terrible mass penalty and eliminates the possibility of an Apollo-13 style free-return. You didn't address this at all either.

Adding segments to an SRB yeilds and improved performance versus adding more SRBs, this is because you don't have to have the heavy thrust vector systems, recovery systems, and the thick steel endcap if you just stretch the booster.

gaetanomarano · 2006-05-09 09:52:43

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When are you going to stop saying dumb things, gaetano?
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since you don't have any courtesy nor education I post my answer only for the other users of this forum

I suggest to build, only ONE capsule, 4.5 mt., bell-sized, for a crew of FOUR (not six) and use it ONLY for moon missions launched with an SLV

an ISS' version can be made with an SM-light and 3/4 crews (but I don't think it is necessary) with a 10-12 tons total weight to be launched with ready available rockets

I don't think that "mars" is a problem to talk now nor in the next 20 years!

this is "my choice"

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NASA is also obliged by international treaty...
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interantional treaties changes every days, it's a matter of politics

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space suits...
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I think that future spacesuites will be lighter than to-day's and past apollo suits

you will see so many innovations of materials and technologies in next 15 years that now we (and, especially, you) can't imagine

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The cost of the rocket fuel is so small....
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but not the cost of the tank and the rockets to launch the extra-weight

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don't built an orbit-only CEV with a half-sized service module...
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I suggest to don't build ANY orbital-CEV, onlu the lunar version

||||||
about the CLV...
||||||

in the story there are thousands of vehicles (of any kind) good "on paper" but wrong in real life... we need to wait to see how much the CLV is good or bad

|||||||||||||
EELVs would require such extensive changes...
|||||||||||||

all past capsule have used rockets (Titan, etc.) like to-day's EELV... now the EELV is "not good" only because many wants to sell the SRB...

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The "real costs" are not that difficult to know...
||||||||||||||||

ask NASA, ESA, etc. about Shuttle, ISS, probes, etc. "planned" costs and REAL costs...

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but it CAN with multiple capsule/ATV flights...
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when the Shuttle will retire, this is the only destiny of the ISS

the unpressurized cargoCEV is deleted, the pressurized (and VERY expensive) cargo-CEV was planned to send 3.5 tons of payload to the ISS in the 5.5mt. version (the 5mt. probably less than 3tons), the Progress carry 2.4 tons (and costs like a car!), I don't see so much advantages with the cargo-CEV

|||||||||||||
two seperate assembly lines for big and small service modules...
|||||||||||||

this only because all insists to build an ISS version of the CEV (that, I think, is completely unnecessary), with so many present and future (VERY CHEAP) vehicles the ISS cargo-crew CEVs are only a giant waste of time and money (that can be used to make more moon missions and sooner)

||||||||||||
what technology is used....
||||||||||||

of course, the technology is used on materials, not on volume

the planned 6x 5mt. CEV is very light if compared with the apollo CM

why?

new technologies and materials!

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jet airliners would be so...
||||||||||||

all products never born perfect including airplanes (many problems are known and solved only after air accidents)

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Your "Plan C" involves direct flight to the Moon...
||||||||||

no

only to launch three astronauts for 10 days missions, the moon-hardware for 5+ missions separately with a cargo-LSAM, etc.

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adding more SRBs...
||||||||||||

my "first choice" is to build a 100 tons payload SLV with to-day's 4-seg. SRBs and lighter missions

.

SpaceNut · 2006-05-09 09:56:50

You are STILL not listening to me about the CLV. It will not be a brand new rocket built from scratch. It will not. The engines will be modifications of old ones, the aerodynamics basically the same as Apollo, even the avionics will be off-the-shelf.

Lockheed Martin’s proposals for NASA CEV may get 787 avionics "and the use of thermal protection system (TPS) material from the US space agency’s Stardust sample return capsule, writes Rob Coppinger." Phenolic Impregnated Carbon Ablator (PICA)
Article is short does have some interesting items...

Lets try to keep the acronyms straight in that the CLV/CEV is DaStick or what may be named Ares I with its CSM, while the CaLV cargo launch vehicle is possibly Ares V. The CaLV is an unmanned ship until joined to the CEV in orbit. The Calv will have the LSAM (Artemis)and EDS.
Integrated Master Schedule

cIclops · 2006-05-09 10:31:13

Lets try to keep the acronyms straight in that the CLV/CEV is DaStick or what may be named Ares I with its CSM, while the CaLV cargo launch vehicle is possibly Ares V. The CaLV is an unmanned ship until joined to the CEV in orbit. The Calv will have the LSAM (Artemis)and EDS.

Good idea. According to the ESAS the CLV, also known as The Stick, will launch the combined CEV/SM to LEO. The CaLV, aka HLV and SDLV, will also lift the EDS and LSAM to LEO. The CEV/SM then docks with the EDS/LSAM and the EDS then moves the whole kaboodle to lunar orbit. Piece of cake.

AFAIK NASA has not used the names Ares I or Ares V. I propose calling the CaLV 'The Griffin' as he's doing all the heavy lifting right now :>

SpaceNut · 2006-05-09 10:48:55

Can I assume gaetanomarano that the SLV is a shuttle derived heavy lift launch vehicle. That you want to have "ONE capsule, 4.5 mt., bell-sized, for a crew of FOUR (not six)" having little room to put on the big bucky space suits. With a layout simular to the lunar mission by the Apollo programs Saturn V.

Here is a link to the currentLunar Architecture to gather numbers from for your design..

You would think that "I think that future spacesuites will be lighter than to-day's and past apollo suits

You will see so many innovations of materials and technologies in next 15 years that now we (and, especially, you) can't imagine " but the case is the ISS is still using designs from back then and they still are very large.

gaetanomarano · 2006-05-09 10:58:25

Can I assume gaetanomarano that the SLV is a shuttle derived heavy lift launch vehicle. That you want to have "ONE capsule, 4.5 mt., bell-sized, for a crew of FOUR (not six)" having little room to put on the big bucky space suits. With a layout simular to the lunar mission by the Apollo programs Saturn V.
Here is a link to the currentLunar Architecture to gather numbers from for your design..
You would think that "I think that future spacesuites will be lighter than to-day's and past apollo suits
You will see so many innovations of materials and technologies in next 15 years that now we (and, especially, you) can't imagine " but the case is the ISS is still using designs from back then and they still are very large.

the CEV don't need to have big spacesuits (only the normal pressurized suits) because no space-EVA is planned (and needed) the big suits are only for lunar-EVA, then can be stored in the big LSAM

a 4.5mt. bell-shaped CEV is not so little if you consider that many internal parts (electronics, panels, cameras, etc.) will be 1/10th the volume and weight of the Apollo CM

however, the CEV may be 5mt. because the main saving of a single launch "lightSLV" moon mission may come from LSAM dimensions, moon-hardware sent separately (for 5+ missions), less fuel in the EDS, etc.

.

GCNRevenger · 2006-05-09 19:34:56

"The escape system has a 0% chance... "

...In the absense of conditions required for it to work. You are trying to mince my words again, and just like last time, you are bad at it. My point is that slapping an escape system on the capsule and calling it good is a false sense of security, the safety of using the system at a particular moment must be considerd too.

"however... we need to see 112 successful CEV launch to make a true comparison... "

Your ignorance is only superceded by your stubbornness.

And you ignored my point about Challenger and the SRB burnthrough, maybe because you don't have a clue how the SRBs work and fail. Let me fill you in, the SRBs are made of big steel tubes filled with the rubbery fuel, all bolted together with gaskets between each segment and topped with a thick steel cap.

If the SRB fails, it will most likly be when one of the seals between the sections fail, since this is their weakest point. This has occured twice, once on Atlantis with no ill effect and once on Challenger resulting in its destruction. If the booster leaks, it will leak horizontally since that is the direction normal to the tube, releasing a powerful jet of very hot gas. On the CLV, if the booster leaks this jet will not hit anything, but on the CaLV/SLV/etc, if the jet is aimed at the main tank as it was in Challenger, the tank will explode.

And an explosion is the least surviveable mode of failure, with or without an escape system, because of the explosion is so big and rapid, the chances that the system will activate in time are not very good, and even if it does the acceleration will have to be very violent and dangerous. The CLV simply does not have this problem, and this is a proven problem.

"I suggest to don't build any orbital-ISS-CEV"

Your "suggestion" is irrelivent, because NASA is going to ignore it and do what it is told, and unless something terrible happens to the ISS or something, this is the letter of the law.

GCNRevenger · 2006-05-09 20:04:52

"I say that the 1.5 l.a. will give to all moon missions a very high risk to fail, nothing else"

Which would make it unworkable. That means you think the ESAS plan won't work, and since NASA thinks it will, you are probably wrong. You are trying to mince words.

"the ESAS plan is mainly (and largerly) founded on political decision to give contracts to the soon retired Shuttle manufactures and save their work force (and I agree with the social aspect of this decision), but, sorry, it don't have any new engineering or ideas built-in"

Thats a lie. The ESAS plan is the best plan to get NASA exploring again within its present budget. It doesn't have any new engineering because it doesn't NEED any.

"not true, the astronauts may die with a big or a little explosion"

Thats dumb. A bigger explosion is less likly to be surviveable then a smaller one.

"may have hundreds little and big DELAYS (or failures) due to hundreds unknown reasons"

Which will all be well known, since we will have been flying it to the ISS for some years before any Lunar trips.

"now we can only speculate about its reliability or give our opinions

of course, I hope that it will be reliable"

If we know what most of the major failure modes will be (possible ways the vehicle could fail), and we know how probable they are, then we can with good accuracy predict the reliability. This is done all the time in the engineering world, from buildings to cars to airliners, we don't have to prove they will work before we can be reasonably sure they will.

"my suggestion to use the SSME is for a manned SLV"

This decision has already been made.

GCNRevenger · 2006-05-09 20:50:58

Overall gaetano, you are still completly ignorant about what makes a rocket safe. It is probably impossible with modern technology to build a rocket that is safe enough just because it doesn't fail, so what has to happen is to put people on a rocket that can SURVIVE a failure. There are many ways a rocket can fail, most of them have to do with the engines. When liquid engines fail, they sometimes will explode, and since the chance of survival in an explosion is low reguardless how good the escape system is, having lots of liquid engines is probably a bad thing. The CaLV can't sustain a failure of any of its SRBs either, which means it won't be alot safer then Shuttle with an escape tower slapped on.

Remember, the escape system is the very last resort, its somthing an astronauts NEVER wants to do. There is no such thing as a "safe" escape system, only less dangerous then being near the booster when it fails.

The engine that NASA has chosen for the CaLV, the RS-68, is also not proven to be reliable for humans. Its not even equipped to be monitored or controlled like an engine that humans should ride on needs to be. Its built to be cheap first and foremost, and so the risk of too many RS-68s failing is probably not much lower then the reliable J-2 engine in the CLV. The J-2 is the only hydrogen-burning engine ever to demonstrate safe emergency shut down during use in an American rocket too, so if they do fail, they probably won't make an explosion.

Segmented solid rocket engines don't generally explode, but they do leak, and putting them beside rather than under a huge fuel tank is a recipe for disaster. The Titan-IV rocket, the decendant of the Gemini's Titan-II, has been lost this way in addition to Challenger. Your rocket cannot fix this problem, but the CLV doesn't have the problem at all.

None of the EELV models except the big tripple barrel can lift any capsule without small strap-on SRMs, and the tripple-barrel has no engine out capability. The little SRMs are efficient and light weight, but they have been traditionally unpredictable and unreliable. NASA shouldn't put people on top of any rocket with them. So, all this adds up to launching the crew seperatly on the CLV.

As far as space suits, materials technology has improved radically in the last thirty or so years, but you know what? Space suits have gotten BIGGER, not smaller! And the CEV should have the ability to mount a space walk without needing the Lunar module's volume or airlock, which means the CEV capsule itself should be big enough to accomodate these suits. That means a bigger capsule, too big to ride on an EELV.

"only to launch three astronauts for 10 days missions, the moon-hardware for 5+ missions separately with a cargo-LSAM, etc."

Now you have TWO LSAMs then, and TWO EDS modules, one for cargo and one for crew. And they both have to work and land very close to eachother near the ideal site, which isn't very likly especially with the lack of navigation beacons or manual landing. Now what were you saying about chance of failure being low?

gaetanomarano · 2006-05-10 06:13:57

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My point is that slapping an escape system...
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after the LAS is jettisoned the abort-procedure MUST be different, before that moment, the procedure must be the better to save the crew, of course

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about Challenger and the SRB burnthrough...
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the images and the sequence of events of the Challenger accident are well known in the entire world, then, it's useless to discuss of it

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Your "suggestion" is irrelivent...
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I don't agree

.

gaetanomarano · 2006-05-10 06:22:25

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you think the ESAS plan won't work, and since NASA thinks it will, you are probably wrong
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can I have my "wrong" opinion?

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The ESAS plan is the best plan...
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in fact, it changes every day...

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A bigger explosion is less likly to be surviveable then a smaller one
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good luck to the astronauts that will be near a "small explosion"

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Which will all be well known...
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like the SRB problem that killed the Challenger and the foam that killed the Columbia...

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then we can with good accuracy predict the reliability...
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ask the engineers that try to launch the Discovery from 10 months...

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This decision has already been made
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like many "final" decisions of the ESAS plan released last december...

.

gaetanomarano · 2006-05-10 06:37:03

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Overall gaetano, you are still completly ignorant...
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where are the moderators of this forum?

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It is probably impossible with modern technology to build a rocket that is safe enough just because it doesn't fail...
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true! this is the main reason the 1.5 l.a. will cause many moon missions fail

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The engine that NASA has chosen for the CaLV, the RS-68...
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this is not my problem, I post only my opinion (that may be different, of course)

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Segmented solid rocket engines don't generally explode...
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but, when explode, they are too fast to save the crew

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None of the EELV models except the big tripple barrel can lift any capsule...
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when (and if...) the CEV will fly with its solid rocket five times more russian and chinese capsules will still fly (reliably and successful) with their EELV-like liquid engines rockets

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which means the CEV capsule itself should be big enough...
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Gemini, Apollo and Soyuz astronauts have accomplished spacewalks without a giant capsule like the CEV

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Now you have TWO LSAMs then, and TWO EDS modules...
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no

the 10 days exploration time of three astronauts equals 7 days with four

no need of two LSAM/EDS

.

GCNRevenger · 2006-05-10 06:58:39

"the procedure must be the better to save the crew, of course

This is exactly what I've been saying isn't true! The escape system is the very very last resort, and should never be used unless it is absolutely nessesarry. Its a much better idea to simply gently push off from the failing booster, perhaps by firing the SM engine, and land normally. The escape system shouldn't be used unless the booster explodes or there is a pad fire most likly.

"the images and the sequence of events of the Challenger accident are well known in the entire world, then, it's useless to discuss of it"

And you want to put a manned capsule on a much larger fuel tank in exactly the same risk.

"can I have my "wrong" opinion?"

Not when your opinion is stupid. Once again, you position is that the ESAS plan will never work, and infact your "plan" involves scrapping the entire NASA strategy alltogether. You can't have it both ways, the NASA plan can't both be unworkable but only being "a mistake," you can't call NASA's plan stupid while not calling NASA itself stupid. Its one or the other, and you are trying to straddle the fence, which is why your opinion is both logically flawed and completly meritless.

"in fact, it changes every day... like many "final" decisions of the ESAS plan released last december"

Only the details of the plan have been changed, the same basic strategy hasn't. The 1.5 launch arcitecture with a two-piece CEV launched by an SRB-based rocket with ISS capability has not changed a bit.

The changes that have been made have largely all been for the better. Abandoning the SSME because it is too expensive to use and modify is a good change, and it won't be reversed because its such a good idea. Abandoning the four-segment SRB is a natural consequence of this choice, and eliminates the need for two different SRB production lines, another good choice. The RS-68 chosen for the CaLV was designed to intentionally trade cheaper engines for bigger fuel tanks and more dirt-cheap fuel, which is another good idea since the original Apollo-building 10m hardware can be resurected. Threatening to abandon the Methane engine for the CEV is another good idea, because it forces Marshall SFS management to "get with the program" or face cuts. Etcetera etcetera... all of these are just changes in the details, and predominantly for the better.

"like the SRB problem that killed the Challenger and the foam that killed the Columbia... ask the engineers that try to launch the Discovery from 10 months."

The former of which cannot occur on the CLV but can on the CaLV, and the latter can't occur with either rocket.

Comparisons with Shuttle are stupid too, beacuse the more complex a vehicle is, it becomes exponentially harder to predict its reliability. Shuttle is the most complex machine ever devised by man, without equal, and it is a testimant to modern engineering that it works at all. The CLV will easily be fifteen, perhaps twenty times simpler, which is why we can trust that it will work and only minor problems fixed in a limited set of tests. This is also why the CLV will be easy to launch on time, because it is so simple, there are fewer things to potentially cause delays.

"good luck to the astronauts that will be near a "small explosion""

Its simple physics, irrespective of how the astronauts "feel," that a bigger explosion will be harder to survive then a smaller one. The CaLV is worse on both accounts, with a much higher risk of blowing up with its six turbopump engines and twin SRBs astride the main tank, plus it carries many times more fuel. Yes it does have limited engine-out ability, but it also has a much higher risk of a lethal explosion.

gaetanomarano · 2006-05-10 07:43:56

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gently push off from the failing booster, perhaps by firing the SM engine...
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it's better but too risky, an human can't decide in milliseconds, then, the only safe way to save the crew is to use the LAS in all emergencies (they can see AFTER they LIVE if the emergency was big or little)

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And you want to put a manned capsule on a much larger fuel...
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the SRB problem was solved and 100% of future manned launches use liquid rockets since, also the CLV, will have a liquid 2nd stage

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Not when your opinion is stupid...
||||||||||||

I'm sorry for you, but I will publish my "stupid" and "wrong" ideas and opinions again and again and again and again and again and again because we are in a free world (if you don't like my opinions don't read them)

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Only the details of the plan have been changed...
|||||||||

details?

||||||||||
The 1.5 launch arcitecture with a two-piece CEV launched by an SRB-based rocket with ISS capability has not changed a bit
||||||||||

good luck!

||||||||||
The former of which cannot occur on the CLV but can on the CaLV, and the latter can't occur with either rocket
||||||||||

again, good luck!

||||||||||
and only minor problems fixed in a limited set of tests. This is also why the CLV will be easy to launch on time, because it is so simple, there are fewer things to potentially cause delays
||||||||||

good luck #3 with the 1.5 l.a. (that will BORN with a "sum-of-delays-failure-option" built-in)

.

SpaceNut · 2006-05-10 08:10:01

It is probably impossible with modern technology to build a rocket that is safe enough just because it doesn't fail...
rue! this is the main reason the 1.5 l.a. will cause many moon missions fail

How when Nasa only plans 2 launches to the moon per year? That is only 2 CLV/CEV and 2 CaLV how can this lead to more failed moon missions... and that will be supported by what the current shuttle budget is for what would be 3 flights to the ISS.

when (and if...) the CEV will fly with its solid rocket five times more russian and chinese capsules will still fly (reliably and successful) with their EELV-like liquid engines rockets

Maybe but Nasa could buy 10 times as many if we could make them at there costs...

10 days exploration time of three astronauts equals 7 days with four

I did a little searching to find out what apollo flight times were. It would seem that apollo 17 was the longest with 12.58 days and spent roughly 3 days on the surface. That would mean approcimately 4 days out plus 4 days back with no landing.

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