Good man. I was just about to say we need to spliter the SpaceXey stuff, but you already did it. That's exactly what I want members to do (self moderate). Remember to post a redirect URL to here in the other thread.Gold star to Lobo!
I decided to make a dedicated thread of this hair-brained idea, as it’s probably getting off topic on the Dynetics thread. And maybe a bit off for the “Engine for Advanced SLS Liquid booster” thread”.http://forum.nasaspaceflight.com/index.php?topic=30308.150http://forum.nasaspaceflight.com/index.php?topic=27714.135My crazy concept, in a nutshell:Take two FH’s, modify the central core on each to interface with the SLS booster interfaces (on one of the sides that don’t have an outboard F9 on them obviously), strengthen that modified core as needed for the new lateral loads. And launch. The FH tri-core booster operates as a single booster. All three F9’s burn out at the same time and the whole FH is jettisoned. No crossfeed obviously. A strongback could be designed to adapt a stock FH to the SLS core. That probably a better way to go, so that there doesn’t need to be a custom FH core designed and built.You now have a booster with more thrust than the Dynetics boster, and should have similar performance overall, that’s basically already designed and flying, and is off-the-shelf, with multiple engine out capability. There’d be some development costs obviously, but I’d think they’d be just a fraction of designing a completely new booster and new or mostly new engines like the Dynetics/F-1B booster or the Teledyne/AJ-1-E6 booster. Maybe even less than the ATK advanced Solid boosters. And the M1D is an all US designed and built engine. Imagine the economics of scale that come from an extra 54 or 108 of them built per year for SLS? As well as another 6-12 F9 CCB’s? In addition to the scale SpaceX will likely already be building them at. That vs. maybe 4-8 F-1B engines per year and 2-4 booster CCB’s (I’m hoping for at least one SLS launch per year, maybe two down the road once we get an architecture plan).Plus, this would also give NASA a dedication Orion crew launcher in FH, with full commonality with SLS boosters. This would be similar to what could have been done with AJAX, except AVH would be a new development. FH will already be flying.Plus, according to Steve Pietrobon, looks like the LEO performance of SLS with FH booster would be a whopping 159mt to LEO! I’ll figure that will come down some figuring the addition of extra mass from a strongback or strengthened FH central core modified to handle the lateral loads of being mounted to the SLS core. But if you are anywhere over 150mt, or ever 140mt, that’s pretty darn good…especially from a booster that NASA won’t have to pay to have developed.Any switch to LRB’s will likely need a new Mobile Launcher, so solid ATK boosters will have the advantage of less infrastructure changes. But I think this would compete very well against other LRB options for SLS. I have no idea of SpaceX is even pondering proposing such a thing though. This is just my hair-brained idea. :-) (And I’ll stop talking about it on the Dynetics thread. :-) )
Why not crossfeed? You can still run all 54 Merlin 1D's at full throttle the whole time... Rather, 36 fall off early with their respective cores, middle cores stay latched on at that point, both with nearly full tanks.Edited for clarity.p.s. I like your idea.
To many engine problem, so-So if SpaceX went with a type of Merlin 2.Used two of the FH booster cores with engine mount for Merlin 2.That is two FH boosters connected together.In between the two boosters have the strong back to connect to SLS core.This way both boosters on a side would separate together.Problem, is there room for two FH booster cores on each side on the MLP ( opening ) and for the flame trench?This could then give the other option for a type of FXX commercial HLV.Problem is SpaceX has shown that they can not deliver on time.If it is not needed until the 5 seg are used up and that is estimated not to happen for about ten years after 2019, then it could be a possible option.
Quote from: Hyperion5 on 03/25/2013 05:05 pmQuote from: Lobo on 03/25/2013 04:47 pmI’d probably suggest going with building the Block 1B upper stage now, and launching that 8.4m upper stage on a single booster core (maybe with a partial prop load) and making that your common upper stage. Especially if there’s no sharing with any other LV other than SLS and the SLS LRB.But, better than any of that I think, is back to my concept of the FH booster. Mount two FH’s as SLS boosters. No need to develop a new upper stage other than the Block 1B stage then. It can launch and test Orion before putting a crew on the SLS stack. Lobo, the engine count we're talking about with two Falcon Heavies mounted onto the side of the SLS is off the charts. To my knowledge, the highest engine count for simultaneous firing was 30 on the N-1, and that failed spectacularly. I've seen Mythbusters struggle with simultaneous ignition with just a few dozen fireworks for goodness sakes. Now imagine trying to fire up some 54 Merlin 1D engines at the same time alongside the four RS-25 engines on the central core. That's 58 rocket engines going at the same time. It sounds like an engineering nightmare. Ed Kyle and Jim are skeptical enough of the Falcon Heavy's design as it is. Now imagine their reactions if you were their boss and said this was the way forward. Hyperion,First, as I understand, none of the N-1’s problems were related to it’s first stage engine ignitions. If any of the engines had failed to ignite, they all would have been shut down on the pad for an abort. They all lit, but then developed vibration problems at various points after that which caused engines to fail, shut down, etc. So I don’t think lighting a large number of engines on the pad is much of a potential problem. I believe much of the N-1’s problems were because the Soviets couldn’t effectively model the vibration conditions with such a large rocket, or test them comprehensively on stands ahead of time. And also the N-1 had relatively complex plumbing those 30 engines had that was fragile. They really just lit their rockets in order to see what they did. The FH may have a lot of plumbing, but that will be a proven configuration by the time it would even be considered.And beyond that, you are looking at this wrong. You are looking at each engine as it’s own separate rocket. Like you are building a new monolithic rocket with 58 engines on the first stage. But instead what you are building is a monolithic core with four engines, and two boosters, each with effectively –one- engine. As all three cores and all the engines act together as a single booster on a side. Each engine is no more than a part of that booster just as any other part of that booster is just a part. A structural element, a panel, a piece of plumbing, etc. (important pieces, no doublt) NASA buys the FH booster because the FH booster has flown X number of times with no major problems and no LOM in 2023 (or whatever time they look at advanced booster). If the FH has been riddled with problems over many years year, then it wouldn’t be a viable option to even consider. So this assumes only that if flies, and flies reliable for several years.You don’t look at the individual engines, or even the individual cores as separate entities. If an engine doesn’t light on the pad, then the whole stack can be shut down. If a single engine shuts down in flight, then an engine on the opposite booster is also shut down. The stack will probably have enough margin that a few engine pairs can go out and still have nominal ascent. You look at the tri-core FH booster as a single booster. It’s reliable, or it’s not. It can withstand an engine out event, or it can’t. This is probably better discussed further over here though:http://forum.nasaspaceflight.com/index.php?topic=31455.0
Quote from: Lobo on 03/25/2013 04:47 pmI’d probably suggest going with building the Block 1B upper stage now, and launching that 8.4m upper stage on a single booster core (maybe with a partial prop load) and making that your common upper stage. Especially if there’s no sharing with any other LV other than SLS and the SLS LRB.But, better than any of that I think, is back to my concept of the FH booster. Mount two FH’s as SLS boosters. No need to develop a new upper stage other than the Block 1B stage then. It can launch and test Orion before putting a crew on the SLS stack. Lobo, the engine count we're talking about with two Falcon Heavies mounted onto the side of the SLS is off the charts. To my knowledge, the highest engine count for simultaneous firing was 30 on the N-1, and that failed spectacularly. I've seen Mythbusters struggle with simultaneous ignition with just a few dozen fireworks for goodness sakes. Now imagine trying to fire up some 54 Merlin 1D engines at the same time alongside the four RS-25 engines on the central core. That's 58 rocket engines going at the same time. It sounds like an engineering nightmare. Ed Kyle and Jim are skeptical enough of the Falcon Heavy's design as it is. Now imagine their reactions if you were their boss and said this was the way forward.
I’d probably suggest going with building the Block 1B upper stage now, and launching that 8.4m upper stage on a single booster core (maybe with a partial prop load) and making that your common upper stage. Especially if there’s no sharing with any other LV other than SLS and the SLS LRB.But, better than any of that I think, is back to my concept of the FH booster. Mount two FH’s as SLS boosters. No need to develop a new upper stage other than the Block 1B stage then. It can launch and test Orion before putting a crew on the SLS stack.
Why not crossfeed? You can still run all 54 Merlin 1D's at full throttle the whole time... Rather, 36 fall off early with their respective cores, middle cores stay latched on at that point (side-core separation) both with nearly full tanks.If they get the reusability thing happening, it could potentially be really cheap at some point too. Edited for clarity.p.s. I like your idea.
If there were three cores on the side of the SLS core how would it look.Would the Falcon cores be in a straight line or would they be curved to the core. Might not be able to cross feed this way. Either way cross feeding the boosters would add more complication.Just having two booster attached to each other acting as one unit could reduce complications. Attaching them to SLS from a strong back that would also hold the two booster together might be a better way to go. I would rather they just look at a commercial FXX ( or similar ) than try and make the Falcon cores work for SLS.http://forum.nasaspaceflight.com/index.php?topic=27275.0
Quote from: RocketmanUS on 03/25/2013 06:49 pmIf there were three cores on the side of the SLS core how would it look.Would the Falcon cores be in a straight line or would they be curved to the core. Might not be able to cross feed this way. Either way cross feeding the boosters would add more complication.Just having two booster attached to each other acting as one unit could reduce complications. Attaching them to SLS from a strong back that would also hold the two booster together might be a better way to go. I would rather they just look at a commercial FXX ( or similar ) than try and make the Falcon cores work for SLS.http://forum.nasaspaceflight.com/index.php?topic=27275.0The FH would be a –standard- FH. It would just need a strongback adaptor, or a modified central FH core to be strengthened to handle the lateral loads of being side mounted to the SLS core. It would look like a bit of an “H” cross section. The outboard FH booster might need some cross bracing and shock absorbers to keep them from moving around too much. The FH will have a different vibration profile when used as an SLS booster rather than by itself, obviously, and that will need to be looked at. FXX is brand new core, and I think SpaceX would need completely new tooling to make cores that big. And that booster would directly compete with SLS. Until such a time when NASA is considering ditching SLS, FXX really has no customer. Certainly no commercial customers are out there any time for a long time for it. FH will be a production booster, and will already exist.
a) The quicker you can kick loose that extra mass the better I’d think. b) separation... if the two outboard F9’s on each side jettison, they actually jettison parallel to the attachment point, rather than out and away from it. Maybe this would be ok, but I wouldn’t want one hitting the SLS core when jettisoned. c) You introduce and extra staging event,
You would need too much mass for the FH outboard boosters to stiffen it.You can't just keep adding metal on metal on metal. That's not how rocketry works you eat into the payload too much.The idea is to have an aerodynamically stable shape so the loads are distributed well enough that you don't have to over engineer the stiffening.Sorry to go throwing cold water on this but I find it absurd.
I don't think that will work. More than likely it would fall apart.Would be better just to attach each booster to the core and have them separate at the same time as one unit.