I'd like to get ONE SLS into LEO at this point guys
Crazy nonricket scientist thought. What kind of solids would be required to give a fully fueled tricore a t/w >1? I'm thinking you could then open the door to Cross feeding the center tank. I am crazy and that becomes a completely crazy rocket bu I thought I would throw it out there as a purely hypothetical question. Thanks
LC-39 compatibility is an issue with this configuration. Boeing probably ran into the same headwinds with its tri-core 8m Delta IV concepts. My initial guess is that such a rocket could fit, but only "sideways", on a purpose-built MLP, but the service tower would have to be grounded, STS-style. VAB hook height is always going to be a limit as well. Basically, this design doesn't meet the "Block 1A" limitations that call for swap-outs with existing SRBs. Those requirements mean that the boosters can't be more than 5.5 meters diameter. I haven't thought about whether or not 5.5 meter diameter boosters could work with these engines, beyond noting the interesting fact that Boeing/MSFC have developed the Ares I 5.5 meter diameter tank tooling, and even built a demonstration tank at Michoud, which is really, really interesting I think. So tri-core doesn't meet Block 1A, but I still like to think about such mega-liquid rockets. - Ed Kyle
Quote from: demorcef on 01/26/2012 09:12 pmI'd like to get ONE SLS into LEO at this point guys Yea, but the ultimate purpose of this rocket is to get to Mars. If you read Chris' article on the new ConOps, a single manned mission to Mars will require 10-15 SLS launches. This rocket needs to be scalable somehow when that time comes and it is prudent to consider that now. One way is to consider some design changes now (or as Block III later on) that would enable the addition of 6-8 Atlas VPII or Falcon X Kerolox boosters, and even perhaps 2 of the 67' SRBs to the outer sides of those.Reading all these ideas of a 3 core SLS CCB, I am starting to think that an even better solution would be a pair of 8.4m KeroLOX boosters. Similar tooling to the core, but you get the actual thrust you need for the first part of the flight. The connection points may need less modification than going with 8 boosters. There is less complexity, fewer launches are needed for a manned Mars mission; that allows more efficient design (and fewer) of the modules to be assembled in LEO. There is less boil off time to worry about and fewer chances of a LOV. I think this thing might look like the Falcon XX Heavy image that someone else created elsewhere on this site.I agree this mega rocket is not needed now, but when it's time for Mars, I just don't think 15 Block II SLS launches is the best approach. Once we reach Mars, we will likely continue missions there and end all the things we've been doing during the lead up. 15 Block II launches for every Mars mission seems unsustainable. We need to think about what Block III could look like way down the road and figure out how we could be a bit penny wise now rather than pound foolish later. I.E. design the pad, flame trenches, acoustic supression for the most evolvable version that could ever be possible and build them that way during the current modifications. I think no extra VAB or crawlerway mods would be needed. We should think now about how the beam that carries the core's weight between the top of the two boosters might need to be changeable in the future if going to 8 liquid boosters or a pair of 8.4m boosters. Even if we don't build it that way now, design it in such a way that the change can be made with minimal difficulty when Block III comes on line.
<snip>I know there will be numerous issues I have not considered, one being the noise decibel level, but I am wondering if this would at all be practicable in any way, shape, or form. I would think a new RP-1 engine with the thrust of an F-1A and the efficiency of an RD-180 is needed, but it looks like Rocketdyne, Aerojet, and SpaceX all may begin R&D as advanced booster competition proceeds, and there have been rumors of the Russians upsizing the RD-180. (With Putin's latest antics, I think we really need to wean ourselves from Soyuz and from RD-180s.) On the other hand, if an engine goes out, is it better to have two RD-180s per booster or cross tanking between boosters? If one RD-180 flamed out and you ran the second one longer, it would need to be jetisoned much later. With a single engine on each booster and no cross tanking, a flame out on a single booster could lead to LOM/LOV. So many liquid engines does add a lot of complexity and a greater statistical probability of an engine failure somewhere. OTOH, multiple STS 130 mt launches to LEOR and docking prior to TMI may have an even higher statistical probability of a failure somewhere in the manifest.I look forward to everyone's feedback on any and all of these thoughts. Thanks in advance for your input.
Hi...I'm a long time listener, first time caller.For a configuration that uses RS-25Es on the core, and RS-68As as strap on boosters, it may be possible to develop a semi-common core for SLS. The fuel/oxidizer tanks and their run ducts would be similar (if not identical), but there could be a generic interface that could accommodate either a RS-25E (for the core) or RS-68A (for the boosters). This would probably require integrating much of the MPS at a subassembly (which would include the engine).
I do like the RS-25E as a core engine with RS-68A as a booster, since these are the designed applications for these engines. On the other hand (the other, other hand?), an all-RS-68A vehicle would eliminate the need to continue funding RS-25 while leveraging the cost advantages of RS-68 use by EELV.
I agree this mega rocket is not needed now, but when it's time for Mars, I just don't think 15 Block II SLS launches is the best approach. Once we reach Mars, we will likely continue missions there and end all the things we've been doing during the lead up. 15 Block II launches for every Mars mission seems unsustainable. We need to think about what Block III could look like way down the road and figure out how we could be a bit penny wise now rather than pound foolish later. I.E. design the pad, flame trenches, acoustic supression for the most evolvable version that could ever be possible and build them that way during the current modifications. I think no extra VAB or crawlerway mods would be needed. We should think now about how the thrust beam might need to be changeable in the future if going to 8 liquid boosters or a pair of 8.4m boosters. Even if we don't build it that way now, design it in such a way that the change can be made with minimal difficulty when Block III comes on line.
Quote from: kirghizstan on 01/25/2012 03:34 pmCrazy nonricket scientist thought. What kind of solids would be required to give a fully fueled tricore a t/w >1? I'm thinking you could then open the door to Cross feeding the center tank. I am crazy and that becomes a completely crazy rocket bu I thought I would throw it out there as a purely hypothetical question. ThanksThere are some concept drawings of such a tricore with two solids on each outer core here somewhere. I think there are others of a pentacore and eight solids too. I will see if I can dig them up. I believe they were drawn by Simcosmos.
Quote from: TomH on 01/26/2012 10:41 pmThere are some concept drawings of such a tricore with two solids on each outer core here somewhere. I think there are others of a pentacore and eight solids too. I will see if I can dig them up. I believe they were drawn by Simcosmos.O.K., found some of the tricore (Jupiter III) pics. The outer cores on this are actually just cross feeding tanks, but with the 4 SRBs, you get the general picture of what you inquired about.http://www.rocketryforum.com/showpost.php?p=198317&postcount=40Am still looking for the pentacore with 8 SRBs.Edit: This page has pics of tricore Jupiter III-X and pentacore Jupiter V-X. All outer cores are actually just tanks which feed to a half stage (engines only) beneath the center core. SRBs jetison first, followed by outer tanks and half stage. Core then ignites as an US. Do not click on the links at the top of the page; just scroll down the page.http://www.amcsorley.dsl.pipex.com/my_orbiter_addons.htm
There are some concept drawings of such a tricore with two solids on each outer core here somewhere. I think there are others of a pentacore and eight solids too. I will see if I can dig them up. I believe they were drawn by Simcosmos.
On the other hand (the other, other hand?)
Quote from: edkyle99 on 01/27/2012 01:58 pmOn the other hand (the other, other hand?)On the gripping hand...cheers, Martin
Is this related?
Quote from: FuseUpHereAlone on 01/27/2012 12:14 amHi...I'm a long time listener, first time caller.For a configuration that uses RS-25Es on the core, and RS-68As as strap on boosters, it may be possible to develop a semi-common core for SLS. The fuel/oxidizer tanks and their run ducts would be similar (if not identical), but there could be a generic interface that could accommodate either a RS-25E (for the core) or RS-68A (for the boosters). This would probably require integrating much of the MPS at a subassembly (which would include the engine). One difference would be the big propellant lines, since the two engine types would need different propellant feed rates. Another difference would be the strength of the stages themselves, since the boosters would have to support more weight, essentially. That would probably require slightly thicker tank skins, but I'm not a structural expert so this is just a guess. There could be a happy "common core" compromise. On the other hand, thicker tank skins on a common diameter tank could likely be milled on the same machines, in the same factory, by the same employees, etc.I do like the RS-25E as a core engine with RS-68A as a booster, since these are the designed applications for these engines. On the other hand (the other, other hand?), an all-RS-68A vehicle would eliminate the need to continue funding RS-25 while leveraging the cost advantages of RS-68 use by EELV. - Ed Kyle
Quote from: TomH on 01/26/2012 10:41 pmQuote from: kirghizstan on 01/25/2012 03:34 pmCrazy nonricket scientist thought. What kind of solids would be required to give a fully fueled tricore a t/w >1? I'm thinking you could then open the door to Cross feeding the center tank. I am crazy and that becomes a completely crazy rocket bu I thought I would throw it out there as a purely hypothetical question. ThanksThere are some concept drawings of such a tricore with two solids on each outer core here somewhere. I think there are others of a pentacore and eight solids too. I will see if I can dig them up. I believe they were drawn by Simcosmos.Sounds like the "Jupiter III" proposal that was floated WAY back around the time ESAS was going on... A Super-Duper-Uber Core flanked by a pair of crossfeeding ET's, each equipped with a pair of SRB's... 4 SRB's and a boatload of liquid engines (RS-68's IIRC) all burning at liftoff... SRB's all sep together, ET's ejected shortly thereafter, core continues on it's own fuel to staging... Later! OL JR