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I think that the 4-segments SRB is BETTER than a new 5-segments booster, as I explain in this comparison chart:
_________________standard SRB_______5-segments SRB____
available_____________NOW!______________2009+
CEV/Ares launch______~2011______________2014+
1st moon landing______~2016______________2020+
R&D costs_____________$0______________$3+ billion!
unit cost_____________$40M_______________$60M+
shared R&D costs_______$0________________$100M+
already man-rated______yes__________________no
manned launches_______115__________________0
successful launches_____114__________________0
launch pad changes_____little_________________big
safety______________very good____________unknown
reliability____________very good____________unknown
reusable_______________yes_______________unknown
shuttle-derived_________100%_____________a little bit
then, the 4-segments SRB is (clearly!) the better choice for all new NASA rockets
the comparison chart is valid also for the 3-segments SRB excluding only the unit price that may be close to the standard version
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...Except the five-segment booster has enough power to lift the CEV and the four-segment booster doesn't. Without the added thrust and specific impulse of an engine like SSME for the upper stage, the smaller but more reliable J-2 engine couldn't do the job without a more powerful first stage. Sorry.
Also, the safety and reliability can be inferred from the smaller four-segment booster, since they are built and operate in much the same way. We know it will be safe and reliable. Your suggestion that the Moon landings will be delayed is nonsensical assumptions too, much of the Ares-I development will take place during Shuttle's last days, but the other vehicles will cost so much more that development now would probably be very slow.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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...Except the five-segment booster has enough power to lift the CEV and the four-segment booster doesn't. Without the added thrust and specific impulse of an engine like SSME for the upper stage, the smaller but more reliable J-2 engine couldn't do the job without a more powerful first stage. Sorry.
Also, the safety and reliability can be inferred from the smaller four-segment booster, since they are built and operate in much the same way. We know it will be safe and reliable. Your suggestion that the Moon landings will be delayed is nonsensical assumptions too, much of the Ares-I development will take place during Shuttle's last days, but the other vehicles will cost so much more that development now would probably be very slow.
the advantages of the 4-segments SRB are so many that NASA may change the 2nd stage to match the better booster
the 3 years delay to develop the new booster (for both Ares) is well known (and the REAL delay may be 1+ years higher!) then... 2014-3=2011 for the first orbital flight and... 2020-3=2017 for the first moon landing
these figures may be very much better building ONE rocket instead of two
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...Except the five-segment booster has enough power to lift the CEV and the four-segment booster doesn't. Without the added thrust and specific impulse of an engine like SSME for the upper stage, the smaller but more reliable J-2 engine couldn't do the job without a more powerful first stage. Sorry.
Also, the safety and reliability can be inferred from the smaller four-segment booster, since they are built and operate in much the same way. We know it will be safe and reliable. Your suggestion that the Moon landings will be delayed is nonsensical assumptions too, much of the Ares-I development will take place during Shuttle's last days, but the other vehicles will cost so much more that development now would probably be very slow.
the advantages of the 4-segments SRB are so many that NASA may change the 2nd stage to match the better booster
the 3 years delay to develop the new booster (for both Ares) is well known (and the REAL delay may be 1-1 years higher!) then... 2014-3=2011 for the first orbital flight and... 2020-3=2017 for the first moon landing
these figures may be very much better building ONE rocket instead of two
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You are assuming that it will be cheaper and/or faster to develop a new, air startable, large cryogenic engine then it is to simply put the five segement RSRB into production. There is an RD cost associated with the fuel change for the CLV, but there have been two 5 segement RSRBs ground fired.
There simply is not a large enough air startable engine in production right now that would allow for the origional CLV configurations, and I can guarantee you that it will cheaper to produce a flight ready 5 segement SRB then it would be to produce an expendable/air startable SSME.
Oh yeah, and let's not forget that to get the life capacity we need out of the Ares V we need the five segement SRB. Please don't counter that argument with by saying we just need a 3 or 4 SRB version of the Ares V, the diminishing returns you get with solids, not to mention unit cost and pad infrastructure pretty much dictates that's not really an option or a good solution.
...
The big culprit in the long development time we are looking at with the Ares I and V is the fact that we still have the great white elephant of the space shuttle and space station on NASA's back. The faster we get ride of those two leeches the faster we will be on our way to the Moon and Mars.
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...air startable, large cryogenic engine...
no need to air-start the SSME... they can use two J-2x or 2+ air-startable engines of Atlas, Delta, Titan, etc. 2nd stage
if the J-2x will be so cheap like I've read around (less than $10M) with the $3B saved NASA can buy 300 J-2x... sufficient for the next 150 Ares-I launches!!!
...don't counter that argument with by saying we just need a 3 or 4 SRB version of the Ares V...
you talk of the 5-segments SRB like of a DOGMA... now, for you (and many other) the ONLY way to build a rocket is the 5-segments SRB !!!!!!!!!!!!!!!!!!!!!!!
the 5-segments SRB is NOT a dogma, and three standard SRB can be used for the Ares-V
the infrastructures must be changed with every rocket configuration
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the advantages of the 4-segments SRB are so many that NASA may change the 2nd stage to match the better booster
the 3 years delay to develop the new booster (for both Ares) is well known (and the REAL delay may be 1+ years higher!) then... 2014-3=2011 for the first orbital flight and... 2020-3=2017 for the first moon landing
these figures may be very much better building ONE rocket instead of two
NASA is huh? Says who?
Hey, 2011 and 2017? A whole year ahead of schedule!
And your're right, we ought to build only one rocket instead of two... only build the five-segment SRB for both Ares-I and Ares-V, instead of both four and five segment.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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they can use two J-2x
J-2 doesn't have the nessesarry specific impulse to make up for not using SSME. One reason why the SSME is so expensive is because it operates at such extreme conditions, but this grants it efficiency higher than any other engine its size yet built.
2+ air-startable engines of Atlas, Delta, Titan, etc. 2nd stage
You'd need twenty RL-10s to match the thrust of one SSME.
the ONLY way to build a rocket is the 5-segments SRB... the infrastructures must be changed with every rocket configuration
Pretty much, yeah. Ares-I needs a five segment since SSME is not practical, and Ares-V needs it to reach the minimum ~120MT payload with only two boosters.
Changing "infrastructure" to support a multi-booster configuration is not practical because it would cost too much money.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Hey, 2011 and 2017? A whole year ahead of schedule!
probably you prefer to ignore the facts that refutes your opinions, but the new official costs/timelines are...
september 2014 (not 2012) for the first manned CEV launch
2020 (not 2018) for the first moon landing
$7B (not $5B) to develop the Ares-I
+$10/15B evaluated increase of R&D costs for CEV/Ares-I over the $5B+$5B planned six months ago
the reality is that, use the standard SRB, may results in a GIANT saving of time and money!
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Changing "infrastructure" to support a multi-booster configuration is not practical because it would cost too much money.
I don't suggest to have two boosters... only the standard version
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2012 for the unmanned test flight was what I was referring to, and the "offical" NASA roadmap stil places the Moon landings at 2018 last I knew.
By "multibooster" I was meaning more than two boosters on Ares-V, to avoid the need for the five-segment SRB. This is not happening, since it will be easier to just make stretch SRBs then it would be to rearrange the whole launch infratructure. Cheaper too.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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2012 for the unmanned test flight...
I refer to the (new) planned date for the first manned CEV launch: september 2014 (+delays...)
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Which was the originally planned date. This is not a problem.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Which was the originally planned date. This is not a problem.
the original planned date was "2012" and, yes, this is not a problem... the main problem will be about DELAYS
all space programs have delays... the question is "how many years of the delays will occur this time?"
I think that a VERY OPTIMISTIC figure is "2 years" (over the NEW planned dates) that means: first orbital flight in 2016 and first moon landing in 2022
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Delays? What delays? The project hasn't even really started yet and you are talking about delays? And why does there have to be a delay? Ares-I is a fairly simple rocket, you have no basis to claim that it will be delayed.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Delays? What delays? The project hasn't even really started yet and you are talking about delays? And why does there have to be a delay? Ares-I is a fairly simple rocket, you have no basis to claim that it will be delayed.
all big projects have delays... Shuttle, ISS, mars exploration, etc.
now we can't know "how many", "how much time" and "why", but we can be sure that also the ESAS plan will have some (little or big) delays
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Interesting argument of 5 versus 4 segments.
Initially I argued against the 5-segment on the CLV out of fear of cost overruns ans developemnt. The trade-off as I noticed NASA pointing out was it'd hasten CaCLV developement, and of the two I have to rate CaCLV of greater value since it could launch anything to the moon on its own.
The 4 segments have the advantage of being proven, and they are after all what the 5-segments are going to be based off of. If the 5-segments prove to be unworkable I'm willing to bet for better or worse NASA will fall back on them anyway it can and I doubt the SRB's makers will frankly care either way since it means buisness for them.
For now I lean toward the 5-segments; yes it means some R&D but it means more capacity for the CaCLV rather than reduced oh-sorry-you-can-only-bring-a-can-of-beans-instead-of-that-Lunar-Keck-3-Telescope-you-hoped-for here-and-now load.
Keep the designs for the 4 though. No sense in mothballing the only man-rated solid rocket yet.
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CaCLV
what do you exactly mean for "CaCLV"?
a big rocket like the SaturnV for a single launch architecture or a mid-rocket for a twin launch architecture?
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The lift capacity of Ares-V ("CaLV" formerly) is non-negotiable, it HAS to be at least 120 metric tonnes, otherwise we should forget all this talk of affordable/sustainable space exploration on the Moon right now so long as we are using the 1.5 launch arcitecture. The only way to do this without excessive development of an even more complicated vehicle (eg quadruple four-segment SRBs, stap on liquid boosters, etc) is with the five-segment booster.
Edit: Infact, I have hopes that it will be closer to 130MT, which would make base building and future Mars vehicles a little easier to accomplish.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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...be closer to 130MT...
the latest AresV configuration IS close to 130 mT, but it don't need the 5-segments SRB since, the same payload (or more) can be launched using three standard SRBs as AresV boosters
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FIVE MONTHS ago I've suggested to build a Single Launch Vehicle [ http://www.gaetanomarano.it/articles/004.html and http://www.gaetanomarano.it/articles/006_superSLV.html ] to save time and money and to avoid the risk of many mission fails due to a "sum of delays" of the "one-and-half" launch architecture of the current ESAS plan.
FOUR MONTHS ago I've suggested to build the new rockets ONLY with ready available (shuttle-derived) hardware as explained in my "FAST-SLV" article [ http://www.gaetanomarano.it/articles/005_SLVnow.html ] and in many posts on space forums!
I've received many critics about my ideas... but in latest weeks I've read many articles and posts on space forums and blogs that support my idea... like the "Stumpy" rocket (with two 3-segments SRBs) and the "Direct" rocket http://forum.nasaspaceflight.com/forums … 24&start=1
I'm happy to see that (now) many peoples agree with my idea!
Unfortunately, we will never see these architecture applied since NASA goes like a train on the AresI/AresV rails!
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Except... none of these plans involve single-launch direct flight to the Moon. The "direct" plan called for in your link involves two launches, both of which have to occur as close together as the 1.5 arcitecture. This is obvious since the direct rockets each lift about 80MT, which is about half of the total throw weight of th 1.5 arcitecture. This is bad for two reasons,
~No Apollo-XIII style crew safety option in the event of CEV system failure. In the 1.5, the only things that must work on the CEV are the SM/CM explosive bolts and the parachute charges.
~[b]Also shares the same failure mode as Challenger![b]
~Uses more J-2 engines than 1.5 arcitecture
~"Direct" 80MT rocket is not large enough for chemical-fueled Mars missions, and is borderline for nuclear.
~Oh, and the cost per unit assumes $40M SSMEs, not the $80M more recently quoted from Rocketdyne
Except... the "Stumpy" Ares-IB doesn't use Shuttle components:
~modified external tank
~low-altitude J-2X varient first stage (possibly)
~high alttude J-2X varient upper stage
~three-segment boosters almost as hard as five-segment
...note in your link here, Ares-1B would require $3Bn to develop the three-segment SRB plus another three billion for the five segment SRB. Some deal.
~[b]Also shares the same booster failure mode as Challenger![b]
Except... none of these plans call for three-booster configurations, unlike yours gaetano. Plus:
~Present Ares-1 will use the same boosters as Ares-V, saving money
~Ares-V will use the much cheaper RS-68 instead of the SSME on the "direct" rocket
~The "direct" rocket is too big for ISS duty
~We need Ares-V class rockets for Mars probably anyway
All these plans seem to focus on deffering work too, and don't really offer much as an alternative.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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...none of these plans involve single-launch direct flight to the Moon...
you know that I prefer (and suggest) the single launch architecture, but the two launch version has some economical advantages since it needs the development of ONE rocket made with ready available engines and launched from ready available pads
also, if the mission will fail due to a "sum of delays" only the EDS and a smaller/cheaper rocket will be lost, NOT the giant and expensive AresV and the very expensive LSAM
"Stumpy" is not an idea of mine but an "invention" of the site that published that "news" about six weeks ago with no evidence (so far) that it is a NASA "backup" design
I don't like "Stumpy" since it may cost like the Ares-I (or more!)
my suggestion is to build ONE rocket (for a single or dual launch architecture) using ONLY ready available engines, no matter the design and the payload of that SINGLE rocket
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I kinda like the Direct option. It might have a better chance at getting thru Congress:
http://www.directlauncher.com/
http://www.launchcomplexmodels.com/Direct/
And the key document itself is available at any of these three URLs:
http://simcosmos.planetaclix.pt/temp/Di … v1.0.4.pdf
http://www.hays.cc/direct/DIRECT_Launch … v1.0.4.pdf
http://www.directlauncher.com/doc/DIREC … v1.0.4.pdf
I still love Ares V though. Maybe a ten-meter core stumpy/Direct option with existing SRBs?
Misc:
Look at the N-1
http://www.rolfstabroth.de/
http://www.ipms-phx.org/
Space elevator--a good payload for Direct
http://www.lulu.com/content/440980
Nice model--and I'm not talking about the rockets.
http://www.cjsaviation.com/
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I kinda like the Direct option. It might have a better chance at getting thru Congress:
OMG do you really want Congress to interfere even more in NASA's technical decisions?
Now some quick comments about "Direct":
What is the basis for the claim that this will save $19B in development cost? The only formal costs available so far are the ones published in the CBO study. They cost the development of the 5 Segment Stick at $4.8B and the Ares V similar "Shuttle-Derived Super Heavy" at $8.9B.
After spending over $100B on a "universal" launch system that couldn't either launch crew safely or cargo cheaply the light was seen and a most rational decision was made: to separate Crew and Cargo. Why does Direct ignore this principal? Furthermore a key design driver of the Crew launcher is to maximize safety by keeping the design simple. Direct builds in risk by using four engines compared with the two used by Ares I.
An exploration Cargo launcher can't be big enough. Mars missions will require a lot of mass lifted to LEO. Ares V will be able to lift twice that of Direct, once again this Direct proposal adds mission risk and complexity.
[color=darkred]Let's go to Mars and far beyond - triple NASA's budget ![/color] [url=irc://freenode#space] #space channel !! [/url] [url=http://www.youtube.com/user/c1cl0ps] - videos !!![/url]
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I agree with Ciclops, if we are intending to go to Mars any time soon, it will be with a mission plan much like MarsDirect or DRM-III. In the former, a rocket with 120MT payload is required, and in the latter if you intend to avoid nuclear rockets the TMI stage will weigh ~120MT. Ares-V is the most practical rocket with the payload nessesarry to begin Mars missions under reasonable budget and time constraints.
The "direct" rocket would be a poor fit for MarsDirect or DRM style missions, the former simply because it can't shoot a payload that size to Mars in one shot (hence no longer being direct), and the latter is still too small to lift the TMI stage unless it is powerd by nuclear rockets. In the case of DRM with nuclear rockets, with their expensive and possibly time-consuming development plus ongoing production cost, are we really saving that much money? Because simple and affordable nuclear engines only decrease the TMI "fuel bill" marginally, it makes more sense just to use a bigger chemical stage and stick with J-2X. To lift such a stage, "direct" is too small. If such a stage were to be lifted in two parts, thats two rockets, and the increase in mission complexity.
So just what are we really saving? They say the fixed costs will be lower, but how? The question mark is how many people will be employed, will this number change alot with one rocket instead of two?
In the near term, we have to have a way to access the ISS, and the "direct" rocket is waaay too big for the purpose of simple crew and light cargo. We would have to fill the thing with sand or lead bricks or throttle back the main engines or something to launch the CEV capsule. AltSpace cannot be trusted to do this task entirely on it own, not yet.
Who came up with this design and website anyway? The page is conspicuous with its lack of stated authorship. Given that it touts the use of standard Shuttle hardware (SRB, ET, launch pads) it seems likely to me the author is a Shuttle-hugger. Frankly, we have to get over this touchy-feely affection for Shuttle and its bits and pieces.
NASA also has to get over its abject, stupifying, and paralyzing fear of change: that changing the VAB and crawlers just cannot be this momentous and vast task, changing KSC and MAF and so on just can't be this frightening boogeyman, the smaller simple things just can't dictate to NASA to radically alter the big and complicated things.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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