Advantages of SDHLV, Magnum, or Shuttle-C???

[john_316]

<br />So on the menu we have the SDHLV inline direct heavy Launcher...<br /><br />So why not Magnum or Shuttle-C/Z concepts to make it to the final cut?<br /><br />Where did this other design come from with 6 SSME's? I sure would like to know.<br /><br />I honeslty don't think that 6 SSMEs on a SDHLV is gonna fly, whats everyone else think?<br /><br />Especially when you can use RS-84 or TR-107 Main engines (I know JP-8 or kerosene)...<br /><br />I don't see awhole lot of info on the SDHLV other than the notes. Perhaps this vehicle design is till premature to specualte on its actual configuration...<br /><br />

 

[rogers_buck]

Six SSMEs? Oh, it would fly. Nothing on this earth could hold it down. Do you have a link?

 

[najab]

><i> As it is the CEV is supposed to go up on a single stick SRB.</i><p>...plus a honking big second stage - somewhere around 250,000lbs worth of it!</p>

 

[najab]

Every time you post that I think "200 tons? That's got to be a mistake." Then I remember - ~3 million pounds of thrust at ignition - the upper stage <b>has</b> to be that big or the thing would take off like an Estes rocket.

 

[mikejz]

Also, why is the SDHLV only flying with two SRBs? It seems logical that four or six would give that booster a lot more kick for not a lot more money. <br /><br />If you went from 2 to four or six SRBs you might be able to fly it in a stage zero style, with the LH engines airlite for higher overall ISP.

 

[mikejz]

If I remember correctly, was'nt the SRB derived CEV launcher or the SDHLV suppose to use a single SSME as a second stage? Thus they would already have to design an airstart.

 

[gunsandrockets]

"Where did this other design come from with 6 SSME's? I sure would like to know."<br /><br />Old news. See the spaceref.com article...<br /><br />http://www.spaceref.com/news/viewnews.html?id=1040<br /><br />...here is the relevant text from the article...<br /><br />"According to sources familiar with the study's final recommendations, the heavy lifter will be a "stacked" or "in line" configuration (one stage atop another) and not a "side-mounted" configuration as is currently used to launch the space shuttle. The first stage will be a modified shuttle external tank with rocket engines mounted underneath. The first configuration will use 6 existing shuttle (SSME Block II) engines." <br /><br />"A growth version for lifting heavier cargos will use three RS-68 engines. The RS-68 engines, manufactured by Boeing, are currently used in its Delta IV family of launch vehicles. Additional engines would be clustered for launching heavier loads such as those needed for Mars missions." <br /><br />"The second stage will have a liquid engine capable of restarting multiple times. The payload will sit atop this second stage inside a large aerodynamic payload shroud. "<br /><br />...it is not clear how many SRB will be used with this design (despite the accompanying image of an older inline design concept with two SRB). Many HLV configurations were studied by Griffin in his paper 'Heavy Lift Launch for Lunar Exploration'. Some HLV configurations did not use any SRB. This paper is available as a pdf file, here is the google link...<br /><br />http://www.google.com/search?hl=en&ie=ISO-8859-1&q=heavy+lift+launch+for+lunar+exploration<br /><br />The main advantage Griffin states for a heavy lift booster is reduced cost per pound of payload. But is Griffin right? Maybe not. Read this

 

[gunsandrockets]

"If I remember correctly, was'nt the SRB derived CEV launcher or the SDHLV suppose to use a single SSME as a second stage?"<br /><br />ATK, the makers of the SRB, mention both the SSME and the older J-2 as possible second stage engines.

 

[nacnud]

Yeah I thought that was odd as well. I've seen developments of the ariane v which keeps the ratio of SRBs to main engines the same. For a 4 SRB 6 SSME desing the altitude/velocity profile would be the same as the current STS, however the ET would have to be redesigned along with the mobile launch pad and maybe other inferastructure. I would love to see what the mass to orbit of sutch a beast would be, SWAG 200 tonnes to LEO.

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>I honeslty don't think that 6 SSMEs on a SDHLV is gonna fly<p><hr /></p></p></blockquote><br />Putting six of probably worlds most complicated rocket engines on one vehicle is IMO the recipe for disaster. Yes, the SSMEs have a good track record, but isnt this largely due to painstaking amount of work and inspection ( which in the end amounts to high cost ) that goes into each one of them ?

 

[tap_sa]

<font color="yellow">"Putting six of probably worlds most complicated rocket engines on one vehicle is IMO the recipe for disaster. "</font><br /><br />Even if there's no disaster why waste state-of-the-art reusable engines in an expandable vehicle? Four RS-68s have almost the thrust of six SSMEs, five would be more than plenty. SDHLV isn't going to be manrated, is it?

 

[gunsandrockets]

"The SSME is too powerful for the upperstage. They are looking at a J2S"<br /><br />Then ATK must be idiots since on their own pro-SRB website they list the SSME as well as the J-2S as a possible second stage engine.<br /><br /><br />http://www.safesimplesoon.com/nextstep.htm

 

[gunsandrockets]

"They also thought the single stick SRB launcher would not need fins or roll control...they had second thoughts. "<br /><br />Yep. Makes about as much sense as saying a heavily modified SRB with a clean sheet design liquid second stage is cheaper and safer than using a Delta IV Heavy for the CEV launcher.<br /><br />I think the SRB for CEV choice was only taken because it supports the SDHLV obsession. On it's own merits the SRB doesn't make sense.

 

[john_316]

You never know they may man-rate the inline if it is built and if they can find a use for it to be man-rated.<br /><br />Now the idea of 4 or 5 RS-68 motors is a good idea for the inline configuration and it also a good idea for the Shuttle-C config too if they go that route.<br /><br />Its all off the shelf main engines and I imagine a modified Delta IV or Atlas V core stage could be used as the cargo carrier container you would think? <br /><br />Is this possible?<br /><br />

 

[mikejz]

Just wondering:<br /><br />If an SRB based LV seem to be such a coat effective solution, why has ATK not persuited it as a launcher in its own right before this? It seems that they should of bid on the Air Forces EELV program...

 

[john_316]

I saw the 6 SSME and 2 SRB Inline configuration on some pre-release notes confirming the Inline configuration. The ET would be configured with 2 SSME directly on the Tail and 2 SSME on each side opposing the SRBs. <br /><br />Here is the link at www.SpaceRef.com <br /><br />http://www.spaceref.com/news/viewnews.html?id=1040 <br /><br />

 

[tap_sa]

<font color="yellow">"a modified Delta IV or Atlas V core stage could be used as the cargo carrier container you would think?"</font><br /><br />What do you mean by cargo carrier container? Payload shroud?<br /><br />Anyway, Delta IV common core first stage might be a good candidate for SDHLV second stage. Some tuning for RS-68 nozzle for even better vacuum performance, make sure air-start works and possibly add provisions for multiple starts.

 

[halman]

john_316,<br /><br />It seems to me that the External Tank is one of the simplest components of a Shuttle Derived Launch Vehicle. If that is the case, why not re-engineer it to be shorter and broader to allow the vehicle to be stacked in the Vehicle Assembly Building? This would also allow a larger area for mounting engines, and enable larger payload shrouds. The expensive stuff is the Space Shuttle Main Engines and the Solid Rocket Boosters, not the External Tank. Building this beast so that major changes are not required at the VAB or on the pads would seem to be a priority to me. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[blacknebula]

"If that is the case, why not re-engineer it to be shorter and broader to allow the vehicle to be stacked in the Vehicle Assembly Building?"<br /><br />The problem not whether or not it can fit in the VAB (it should be roughly the size of a Saturn V), but whether it can fit on the FSS, which it cannot without a significant modification. That's where a good portion of the in-line vehicle's cost will come from.

 

[samo]

FSS ???? Years ago I proposed a "Double-Shuttle" (effectively: 2, belly-to-belly, only 1 to orbit -- at that time the Enterprise could still be rigged for such suborbital use. About 2-to-3 times the cost of a single launch for 6+ times the cargo).<br /><br /> I figured 2 crawlers, etc, but do you know of more Limits it would violate?<br /><font color="blue"> - - - - - - - </font><br /><br /> Now that I've asked you to cut down my (probably obsolete or impossible) Baby, let me give you my opinion of the post-SSTO/NASP Ideas:<br /><br /> <b> Forget Solids ! </b><br /><br /> - - their shaking breaks the Cargo. The military ABSOLUTELY ruled out (big) Solids when they cancelled the Titan, choosing the Delta BECAUSE they did not want <br /><br /> "another Solid"<br /><br /> . . . but the Budget Office (OMB) changed the enlarged Delta into a Mostly-solid monstrosity.<br /><br /> The 3 half-Super-Delta tests, 2 losses & a grossly low orbit (due to Srb fuel being expelled in chunks as is apparent from the early overthust), showed that even though we now will avoid explosions that are visible by thickening the casing), the Wacky "Slumping of the Fuel" explanation is Garbage, & all the measures taken to curb this nonexistant threat cannot stop Combustion Instability, just hide it.<br /><br /> Why don't they put back the Inside Sensors that showed <font color="yellow"> <b> LOCALIZED TRANSIENT OVERPRESSURES </b> </font>when used on the first Titan IV SRMU test before it blew up ?<br /><br /> When you forbid people to LOOK, you know there HAS to be something there.<br /><br /> So either give up Solids or accept them breaking & shaking the Cargo. But Don't PRETEND.<br /><br /> Frankly, I recall an early 1976 Proposal for a "Downrated Shuttle" (No Srbs, Rp-1 tank under the ET & an RP/Lox engine that the astronauts could detatch & pop into the payload bay, on orbit)).<br />Looking again at that might be better.<br /><br /><br /> The fact

 

[propforce]

"....Eisenhower Built the St. Lawrence Seaway, The Interstate Highway System, The Nuclear Triad, and started NASA. How come we cannot build ANYTHING now? ....."<br /><br />Ummm... too many critics ?<br /> <div class="Discussion_UserSignature"> </div>

 

[john_316]

Samo I think personally we all need to realize the days of the Shuttle are quite frankly coming to there end.<br /><br />We could always sell the system to a private enterprise but I doubt anyone will buy it, included United Space Alliance.<br /><br />We need several lifters for man-rate and just cargo. We can pretty much deliver cargo on any rocket in our inventory but thats not so for astronauts.<br /><br />We have to have at least one for the CEV. It would be nice to launch both the CEV on the EELV Heavy versions and the SRB derived vehicle as well. Thus we mave assured access to space and in an emergency we could call on 3 different vehicles to launch a rescue mission.<br /><br />We will have to get to a point were we need reliability and other safegaurds for launch and recovery...<br /><br /><br />I don't debunk your idea of the 2 ET tanks but I think that the Inline Version is the route to go. If they chose this route within a month after Columbia we would be already at work on the Inline HLV. <br /><br />But we have to look at prorities and yes "Jobs" not just for the engineers and managers but the very people who build these machines.<br /><br />If we go the Shuttle-C route then we have a large cargo carrier like the shuttle and it may save some jobs and give NASA an excuse to make a Shuttle-2 in the future but I doubt that. <br /><br />We need to look beyond LEO folks. Yes the ISS can do the science we need but we need to look at the broader picture here.<br /><br />Unless we have a few more wars to cut the population. The population of this planet is getting larger and we need to sustain the food supply and for those who do environmental studies the earth proper. <br /><br />What I am proposing is that the heavy lifters are what we need if we are to go beyond this little blue marbel. 4 to 6 flights of Delta or Atlas missions to Mars with crews is not worth it. We need something that can lift 100 tons into orbit. The EELV HLV's can accomadate the lesser cargo weights in between

 

[gunsandrockets]

"We need several lifters for man-rate and just cargo. We can pretty much deliver cargo on any rocket in our inventory but thats not so for astronauts."<br /><br /> "We have to have at least one for the CEV. It would be nice to launch both the CEV on the EELV Heavy versions and the SRB derived vehicle as well. Thus we mave assured access to space and in an emergency we could call on 3 different vehicles to launch a rescue mission."<br /><br /><br />Thank you! I'm glad someone else realizes the importance of this besides myself. I even devoted an entire thread to the idea of redundancy...<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=missions&Number=232229&fpart=1&PHPSESSID=<br /><br /><br />"What I am proposing is that the heavy lifters are what we need if we are to go beyond this little blue marbel. 4 to 6 flights of Delta or Atlas missions to Mars with crews is not worth it. We need something that can lift 100 tons into orbit. The EELV HLV's can accomadate the lesser cargo weights in between them and SDHLV. "<br /><br />"...It makes sense to make future Mars and Lunar trips worth while for the trip and carrying the house there is better than living out of an RV while there. HLV can launch the Lunar and Mars Landers and prefab bases as well..."<br /><br /><br />I gotta disagree. Looking at the long term what is really needed isn't heavy lift vehicles what's needed is Nuclear Thermal Rockets and Nuclear Electric Rockets. It would be nice to have both heavy lift and nuclear rockets, but I believe the budgetary reality is we will end up only with one of these technologies. I think the cost of heavy lift will strangle nuclear propulsion.<br /><br />The problem of deep space flight is that even with nuclear propulsion the vast bulk of the mass lifted to LEO for the mission is going to be propellent and not payload. Deep