hyper_snyper - 14/4/2006 4:40 PMAre you assuming CaLV ISS construction? Because 4 boosters just to get to the ISS is a bit overdoing it.
mong' - 14/4/2006 4:57 PMwow, that 200 tons figure is impressive, now what about the feasibility of attaching 4 SRB's to the CalV ?
kraisee - 15/4/2006 12:28 AM GLOW: 10,800,000 poundsLiftoff Thrust: 10,750,000 pounds
Crispy - 15/4/2006 8:29 AMI guess it would have to sit on the pad, burning propellant until it's 50,000 pounds lighter
Tap-Sa - 15/4/2006 5:28 AMQuotekraisee - 15/4/2006 12:28 AM GLOW: 10,800,000 poundsLiftoff Thrust: 10,750,000 poundsIn order to actually get off the pad the Liftoff Thrust should exceed GLOW, no?
BarryKirk - 17/4/2006 8:30 PMWith all of that lift capacity, we could still have a useful cargo landed on the moon even if they use hypergols....
Bad thought, Bad thought.... Must shoot myself in the foot before thinking that one again....
gladiator1332 - 17/4/2006 10:45 PMIn terms of development costs, how much extra are we talking? And that really doesn't matter, as the current plan with the "Walmart lander" just isn't worth it.And more importantly, what are the chances of this actually happening? Is there a high probability that as we speak some NASA engineers are crunching numbers and putting together a report?
kraisee - 18/4/2006 1:47 AMThe other critical place where significant additional costs will come in the design phase is going to be in software development. I can't quantify that myself, but it will take a while to do, and that'll cost a pretty penny.I don't think either of those will be enormous additional charges, and are not even close to being show-stoppers.
BogoMIPS - 18/4/2006 1:16 PMHi all.kraisee, one other cost change you aresn't taking into account with 4 SRBs is that the existing pad infrastructure can no longer support the design. As long as the launcher is in the same form factor as STS, the existing launch pads, flame trenches, etc. can be used. If we strap on two more SRBs, you'll have to revamp the pads as well as the launchers, which will incor even more costs.I'm not saying it's a bad plan, but it certainly is another cost to consider in the system design.
BogoMIPS - 18/4/2006 10:18 PMI'd also love to see a 200 metric ton "Skylab on Steroids"...
lmike - 19/4/2006 1:42 PM If we put our eggs, as it were, into this one basket from the onset, do we forgo a more flexible and robust approach? (i.e. if we decide we want to do orbital assembly, have we wasted time and money?)
lmike - 19/4/2006 9:12 AMIt rings true, but the current ESAS (seemingly?) is in opposition to the old advocated assembly plan. Multiple launches==bad, as I read it.
Kayla - 20/4/2006 7:02 AM Atlas is currently at 78 successful launches in a row, including Atlas II, III and now V.
kraisee - 20/4/2006 12:54 AMThey've learned that a station as big as ISS could have been launched on just three Heavy Lifters, instead of the 50-60 flights of Shuttle, Proton, Soyuz and eventually Ariane flights it actually is going to require.The practical limit is between 100-200mT for a Heavy Lifter. That's also a good area on the ol' price:performance curve too. While a super-heavy would be cool, it's just not necessary. A handful of plain Heavies can loft 500 tons - which is enough to get us truly going 'out there' without additional expense.But without a heavy of reasonable performance, we're going to languish in LEO forever.Ross.
Kayla - 21/4/2006 6:02 AMIf a lunar mission required 150 mT this would require ~6 Atlas or Delta HLV’s (25mT for Delta or 28 mT for Atlas). For a Mars mission of 500 mT this would require 20 launches, not the 400 Kraisee refers to. Beyond the incredible cost savings, Tap-Sa had it right. The Atlas and Delta rockets will have built up dozens of launches by the time the CEV is ready to fly, demonstrating their reliability.
R&R - 20/4/2006 12:05 PMQuoteKayla - 21/4/2006 6:02 AMIf a lunar mission required 150 mT this would require ~6 Atlas or Delta HLV’s (25mT for Delta or 28 mT for Atlas). For a Mars mission of 500 mT this would require 20 launches, not the 400 Kraisee refers to. Beyond the incredible cost savings, Tap-Sa had it right. The Atlas and Delta rockets will have built up dozens of launches by the time the CEV is ready to fly, demonstrating their reliability.Both the Delta IV and Atlas V Heavies can be given minor modifications which can get to 50 mT, that won't cost much and can work with existing Pads (maybe slightly modified) and will have the demonstrated reliability neither of the new NASA vehicles will. I don't care if CLV and CaLV are derived from Shuttle and Apollo they'll really be very new and untried.I'd propose that NASA go with the modified EELVs and use both. This would allow them to launch faster and put up the 3 to 4 pieces needed for whatever it was they were going to put up in one piece at 150 mT. In fact I'll bet what they end up with weighs barely 100 mT total. The launches could be accomplished in 3 to 4 months. The first two could be only days apart. Delta IV even has an edge in that they can up to 4 Heavies ready to at the same time, 1 on the Pad and 3 in the HIF assembled and ready to go to the Pad. Atlas can have all the parts ready to stack in the VIF for probably 2 or 3.
Kayla - 20/4/2006 5:47 PMI think that Kraisee is missing the point. Why hold exploration hostage to development of new rockets??? The EELV’s in the 25 mT class are nearly available today. Finish qualification of the Delta, and the final integration of the Atlas HLV (95% of which is flying on the other Atlas variants). Lockheed is willing to foot the bill to finish the Atlas HLV with a single HLV launch contract, meaning that NASA doesn’t have to spend a dime on development, just order one. Minor changes are required for both Delta and Atlas to launch crews, health monitoring to let the CEV know if it should abort, and crew access at the pad. Once again with orders, both companies probably will foot this bill as well.Because of NASA’s desire to “own” a rocket, NASA is diverting money away from real needs including science and the rest of the lunar exploration effort. If NASA were really focused on their mission, they wouldn’t develop the CLV and CaLV, freeing up the funds to fully fund the science missions (recover the $5B that was recently diverted). The robotic lunar exploration program (RLEP) could consist of more than 2 missions between now and 2012, truly paving the way for human exploration. The in-space and LSAM stages and lunar habitat development could be started immediately. We could be ready to land people on the moon in 2014, about the same time NASA currently is planning on launching the first people on the CLV/CEV.
Jim - 21/4/2006 11:04 AMThe HIF doesn't have the room for 3 Heavies, only 2. The south side is not for LV's.
Also they only have one LMU for a heavy.
Additionally, they can't perform any testing in the HIF, which is why they don't have the next vehicle (a heavy) ready to go to pad after GOES.
Atlas only has room in the ASOC for 1 equivalent Heavy
My take is both EELV's for CLV and a SDLV for CaLV
R&R - 20/4/2006 7:24 PMQuoteJim - 21/4/2006 11:04 AMThe HIF doesn't have the room for 3 Heavies, only 2. The south side is not for LV's.The 3rd bay in the HIF is big enough to hold 3 Boosters and the Second Stage, maybe not mated but that's a minor delay in that they would need to move them over to another bay when it opened up.. They would just have to clear out all the stuff being stored there. QuoteAlso they only have one LMU for a heavy.More could be built in short order.QuoteAdditionally, they can't perform any testing in the HIF, which is why they don't have the next vehicle (a heavy) ready to go to pad after GOES.Testing has nothing to do with it. They eliminated testing in the HIF becuase it just cost a lot of time any money for no gain. The Heavy there now is not ready because there's no rush, the strike kept them from getting ahead on it and it still would be a couple of weeks after GOES launches before the Pad would be ready.QuoteAtlas only has room in the ASOC for 1 equivalent HeavyThat's too bad but I'll bet they could find someplace in all those leftover Titan facilities to put more if they needed to.QuoteMy take is both EELV's for CLV and a SDLV for CaLVAny use of EELVs would be a good ting and real progress for the exploration initiative.
Kayla - 20/4/2006 7:51 PMJim,To finish the Atlas HLV is a very small fraction of $1B. The Cadillac version of flying Astronauts on an Atlas does approach $1B, but many options exist for much less. These low cost options are being developed to support commercial tourism, where investment $ actually is important.
Jim - 21/4/2006 5:45 PMQuoteR&R - 20/4/2006 7:24 PMQuoteJim - 21/4/2006 11:04 AMThe HIF doesn't have the room for 3 Heavies, only 2. The south side is not for LV's.The 3rd bay in the HIF is big enough to hold 3 Boosters and the Second Stage, maybe not mated but that's a minor delay in that they would need to move them over to another bay when it opened up.. They would just have to clear out all the stuff being stored there. QuoteAlso they only have one LMU for a heavy.More could be built in short order.QuoteAdditionally, they can't perform any testing in the HIF, which is why they don't have the next vehicle (a heavy) ready to go to pad after GOES.Testing has nothing to do with it. They eliminated testing in the HIF becuase it just cost a lot of time any money for no gain. The Heavy there now is not ready because there's no rush, the strike kept them from getting ahead on it and it still would be a couple of weeks after GOES launches before the Pad would be ready.QuoteAtlas only has room in the ASOC for 1 equivalent HeavyThat's too bad but I'll bet they could find someplace in all those leftover Titan facilities to put more if they needed to.QuoteMy take is both EELV's for CLV and a SDLV for CaLVAny use of EELVs would be a good ting and real progress for the exploration initiative. Having vehicles on site and not being able to integrate them doesn't buy you anything. So what if the south side can store CBC's, so can Decatur or the Delta Mariner for that matter. Also the second stage nozzle needs to be kept vertical as much as possible. Mating is not a minor delay. It has been taking a lot more time than was thought.The Delta IV program has said under its breath, that it wishes that it could do HIF testing. The DSP booster could be nearly all checked out now. But since it is only mechanically mated, they have to wait until the pad is free and do the checkout, which always finds problems.
Jim - 20/4/2006 9:08 PMI was referring to interface testing CBC with the second stage and/or with strap on CBC's. Atlas can also do spacecraft interface test (abet with a spacecraft simulator) horizontally in the ASOC.
Jim - 20/4/2006 8:03 PMQuoteKayla - 20/4/2006 7:51 PMJim,To finish the Atlas HLV is a very small fraction of $1B. The Cadillac version of flying Astronauts on an Atlas does approach $1B, but many options exist for much less. These low cost options are being developed to support commercial tourism, where investment $ actually is important.I meant to manrate the vehicle and mod the launch complex. The Atlas X, Chris is refering to (I believe), is the Phase 2, 5.4m single core for crew launching.
Avron - 20/4/2006 11:08 PMYou know $1B, in this game is really not a lot of cash...
HailColumbia - 21/4/2006 12:02 AMQuoteAvron - 20/4/2006 11:08 PMYou know $1B, in this game is really not a lot of cash...It is when the total NASA budget is like 14B
Kayla - 20/4/2006 4:47 PM... Finish qualification of the Delta, and the final integration of the Atlas HLV (95% of which is flying on the other Atlas variants). Lockheed is willing to foot the bill to finish the Atlas HLV with a single HLV launch contract, meaning that NASA doesn’t have to spend a dime on development, just order one. ...
ericr - 21/4/2006 5:08 AMQuoteKayla - 20/4/2006 4:47 PM... Finish qualification of the Delta, and the final integration of the Atlas HLV (95% of which is flying on the other Atlas variants). Lockheed is willing to foot the bill to finish the Atlas HLV with a single HLV launch contract, meaning that NASA doesn’t have to spend a dime on development, just order one. ...Wow, is this really true? We managed to pay for the launch of the dummy sat for the first Delta heavy. Why not do the same for Atlas? What would this single launch contract cost?
Kayla - 21/4/2006 2:16 PMJim,The ESAS report specifically refers to an Atlas X which is not equivalent to any of the final solutions coming from the Atlas folks. This consists of an 8.4m diameter core with 5 RD180s, 2 of the existing Atlas V LRB’s (single RD180) and a very large upper stage with 4 J2S’s. See page 24 & 80 of the ESAS report:http://www.nasa.gov/pdf/140637main_ESAS_06.pdf
kraisee - 17/4/2006 10:47 PMThe tanks structures are going to have to be radically re-designed anyway, but we're going to be increasing the diameter from 8.7m to 10m, and extending the length by about 1/3rd over the current ET, so there's no "additional" expense if the choice for quad-SRB's is done at this early stage of the design. Changing from a dual-SRB to quad-SRB system later would be extremely costly though, so it's better to do it now if there's any chance it will go that way. Best to just develop it once.
gladiator1332 - 22/4/2006 10:58 AMSo something more like this:
Avron - 23/4/2006 8:27 PMQuotegladiator1332 - 22/4/2006 10:58 AMSo something more like this:Plus...http://forum.nasaspaceflight.com/forums/get-attachment.asp?attachmentid=4536sold...Anyone want to have a guess at the costs...
FransonUK - 26/4/2006 8:21 AMSorry if this sounds dumb, but surely 4x4 seg is cheaper than 2x5seg?
Jim - 26/4/2006 9:08 AMQuoteFransonUK - 26/4/2006 8:21 AMSorry if this sounds dumb, but surely 4x4 seg is cheaper than 2x5seg?Can't really answer that.4x4 might have more VAB and MLP mods 4x4 might have a more expensive ET.2x5 has more development costs (but then can be offset if the Stick uses it)
Avron - 26/4/2006 10:45 AMQuoteJim - 26/4/2006 9:08 AMQuoteFransonUK - 26/4/2006 8:21 AMSorry if this sounds dumb, but surely 4x4 seg is cheaper than 2x5seg?Can't really answer that.4x4 might have more VAB and MLP mods 4x4 might have a more expensive ET.2x5 has more development costs (but then can be offset if the Stick uses it)Jim... wanna have a guess at the cost of the 4x4? if the VAB is a no-no.. stack at the pad?
Kayla - 30/4/2006 8:57 AMThere is a down side to a super heavy launcher, all the eggs are in one basket. 1 failure and not only do you loose the EDS, or the LSAM or a signficant piece of a lunar base, you loose it all. With the increase in engine count (without engine out) and staging events the reliability goes down. With smaller mass launches you do add the headache of orbital rendezvous, but each launcher is more reliable. You build in the to the proces backups so that if a launch failure occurs you keep going.
Kayla - 20/4/2006 4:47 PMI think that Kraisee is missing the point. Why hold exploration hostage to development of new rockets???
publiusr - 30/4/2006 4:39 PMQuoteKayla - 20/4/2006 4:47 PMI think that Kraisee is missing the point. Why hold exploration hostage to development of new rockets??? You are missing the point. The LACK of new vehicles is holding exploration hostage! The EELV only apologists are holding exploration hostage. 120 tons to orbit atop CALV needs only one launch with engine out. You will have to expend 15 to 18 such RS-68s on five Delta IVs to do what CaLV will do in but one launch. EELV will cost **more** over time. Five CaLVs and you still have your RS-68 engines produced--but you will have 500 tons in orbit in only five launches.THAT is REAL exploration!
Kayla - 30/4/2006 6:52 PMQuotepubliusr - 30/4/2006 4:39 PMQuoteKayla - 20/4/2006 4:47 PMI think that Kraisee is missing the point. Why hold exploration hostage to development of new rockets??? You are missing the point. The LACK of new vehicles is holding exploration hostage! The EELV only apologists are holding exploration hostage. 120 tons to orbit atop CALV needs only one launch with engine out. You will have to expend 15 to 18 such RS-68s on five Delta IVs to do what CaLV will do in but one launch. EELV will cost **more** over time. Five CaLVs and you still have your RS-68 engines produced--but you will have 500 tons in orbit in only five launches.THAT is REAL exploration!SDLV plans to spend ~$20B on non-recurring prior to the first lunar mission. I’d be a hero if I could get NASA to buy 100 Atlas V HLV’s for $20B! At 5 HLV’s per lunar mission this is 20 lunar missions using HLV’s before SDLV is ready to start launching the first one. Explain to me how the EELV crowd is holding exploration hostage?
wannamoonbase - 30/4/2006 9:55 PMOkay, I have had my fun commenting on the short comings of the ESAS. But unless W wakes up one morning and starts caring about space more than any president since Kennedy the plans aren't going to change.For better or worse we are all going to end up getting the CLV for the CEV. So perhaps we should discuss things other than EELV this and SRB that.Some good comments but rather repeatitive.
gladiator1332 - 30/4/2006 9:56 PMAr ethe pads for said EELVs ready for manned flights? Do they have a crew accessway, ya know, so were not hoisting them up there in a cherry-picker. The EELV option doesn't mean we are just going to slap a CEV on top of the thing and boom were ready to go. There are going to be development costs to ready the EELVs. You are dremaing if you don't think NASA is going to spend a couple billion "manrating" these vehicles.
kraisee - 1/5/2006 2:46 AMAlso, I would like to see a replacement liquid powered design for the SRB at some point too. That's where I think the EELV guys should really be focussing their energy now that they are out of the running for this now. A direct upgrade for the SRB's will be needed whenever the EPA finally get their teeth into the perchlorate issues, and if LM/Boeing/ULA have an alternative ready in the wings at that point they'll get a real lot of attention from NASA then.I'd like to see a 3m+ lb booster, designed to burn for about 135 seconds. Probably fuelled by RP1/LOX, with something like 3 x RS-84's under it, or four RD-180's (assuming legal stuff is okay) or maybe brush off the old F-1A designs and create an X version of it to go with the J-2X! Just two of those would be needed. At an average 3m+ lb, it would increase the payload capacity too, which is always advantageous.Ross.
kraisee - 11/5/2006 2:05 PMFor my money, the CaLV core is pretty good as it is. Higher Isp from a "Block-II" RS-68 should be looked at to increase performance though. And I'd replace the SRB's with RS-84-powered flybacks. But I'm happy to leave both of those "upgrades" until later on in the program and get us flying ASAP with the hardware they're already planning to fly.Ross.
Jim - 11/5/2006 3:11 PMstudies of RS-68 upgrades are being funded as we speak, with the idea of incorporating them once they mature
kraisee - 1/6/2006 6:38 PMWhile you'd pay a mass penalty for having the stage inside the payload shroud (like a Centaur), you'd get a mass benefit in return because you could reduce the boiloff rate significantly.
I'm curious whether LM will bring that proposal to the table when the EDS RFI eventually comes out of NASA in a few years time.
kraisee - 11/5/2006 2:05 PMIt's not as simple as just replacing RS-68's and LH2 fuel for sufficient RS-84's and RP1 fuel to get the same thrust. There are an awful lot more factors to consider which effect the overall performance.I've run some simple tests here and the vehicle can't fly successfully just replacing the CaLV's core stage with similar power from RS-84's and the different fuel config. It actually runs out of gas far too early for the Upper Stage to successfully insert the payload into orbit.If the vehicle were radically changed, you could get something to fly which would be "interesting", but the RS-84 is not ideal for this sort of application. RS-84's are most ideally suited to be used as first stage booster engines with a relatively short burn-time early in the flight.To get into the ballpark of a fairly ideal 1.3:1 liftoff thrust:weight ratio using the RS-84, you end up putting enough fuel on board which will get you only around 170 to 200 seconds of burn time.The RS-84's burning that long could offer considerable extra power if used as boosters for the CaLV (the SRB's burn out around 135s), but they get nowhere close to the massive burn time of 450 seconds the CaLV core stage will provide so that the EDS can take over increasing the launch velocity for just the final few minutes of the flight.For my money, the CaLV core is pretty good as it is. Higher Isp from a "Block-II" RS-68 should be looked at to increase performance though. And I'd replace the SRB's with RS-84-powered flybacks. But I'm happy to leave both of those "upgrades" until later on in the program and get us flying ASAP with the hardware they're already planning to fly.Ross.
Tap-Sa - 19/4/2006 7:11 AMQuotelmike - 19/4/2006 1:42 PM If we put our eggs, as it were, into this one basket from the onset, do we forgo a more flexible and robust approach? (i.e. if we decide we want to do orbital assembly, have we wasted time and money?) Well, not quite. The ongoing question is where goes NASA's orbital assembly 'pain threshold'. IOW at which point do they bite the bullet and accept it as nominal part of the mission. It is inevitability and in a way it's already part of moon mission anyway. LSAM and CEV has to assemble, twice, for a succesful mission. What's the fundamental difference of that compared to, say launching EDS LOX in multiple tanks using smaller launchers and connecting them in orbit? IMO none, one requires just more launches than the other.Mars mission would require orbital assembly of several CaLV payloads. I doubt there will be ~500t superheavy vehicle to launch it in one go and not even in two. To develope such for just a couple launches per decade would be extraordinary costly. I don't see manned Mars missions happening at faster rate than that for a very long time.People (Zubrin being among the most vocal) object orbital assembly and claim it dooms any mission if single failure happens during multiple launches. IMO this reasoning is wrong. Each part launched should have a backup standing by. If EDS LOX tank #4 launch fails, tuff, send another. You ought to have at least one spare already built because AFAIK the idea is to keep going to the moon, not just stick another flag there once or twice.Above scenario would require such thinking that the failed LOX launch would not ground the launch vehicle for two years to investigate what went wrong. Of course you investigate but while doing that you keep launching because you have to accept the fact that these things aren't perfect. If you use an established EELV class launcher with maybe 100+ successes under belt and then the #4 oxygen tank flight fails, it does NOT denote that the vehicle suddenly became a miserable death trap and next launch without any modifications would fail with 99% certainty. The mission would require only one extra flight.Propellant transfer/storage is a major issue in true orbital assembly for lunar or Mars mission. Waiting months with LH2 boiling in the tanks is not a good deal. Intermediate solution might be to launch and assemble LOX tanks first, and LH2 in last shot or just before the crew. Proper permanent solution is to have an orbiting garage/fuel depot where you assemble your craft and fill her up when ready.
kraisee - 13/4/2006 11:01 PMCaLV's core stage is going to be an all-new design booster anyway, so choosing to do this sort of configuration at this early stage adds very little to the costs for development.You need to re-design the large "bracing" structure located between the LOX and LH2 tanks in the ET-derived stage, where the forward attachment points are today on the ET. It has to be redesigned anyway to cope with the change to 5-segs anyway, so changing it isn't a big deal. Then add another set of aft attachment points to the LH2 tank structure, near-enough exactly the same way as is done currently. The structure then needs to be designed to suit the loadings, but that's all going to have to be done anyway (adding engines under the ET is a much more significant change to the design), so it's not that big of a deal. Add all the necessary wiring, avionics and other misc. items for the new configuration and it should be hot to trot.I can't see much reason why you couldn't fly a "Heavy" CaLV with just two boosters though - assuming all your software can handle the differring configs. There would be a slight payload penalty, probably around 5-10mT for flying a quad-SRB config with just 2 SRB's, but it could be done.But if you re-design the ET now for just two boosters, and try to upgrade it later, you'd have to pretty-much start the whole design process over once again.
PaulL - 30/10/2006 7:03 AMThe 4 SRBs growth option would be expensive but how does that compare with the performance/development cost of the 2 x 5 segments SRBs + 3 RS-68R on the core tank growth option proposed by Kraisee?
kraisee - 29/10/2006 10:52 PMA far more cost effective solution is to keep pretty much everything we have today in place and reuse it as closely to 'as is' as possible, to launch about 70mT on every flight. DIRECT-ly.For that same $10Bn, DIRECT could launch about 70 launches! That's 4,900mT in LEO for the same money as the very first 4xSRB booster flight.Ross.
kraisee - 29/10/2006 5:52 AMThere are actually a lot of problems with 4xSRBs.The Crawlers can't shift that much mass for a start. The Pads, VAB and MLP's would all need extensive re-design work. And NASA would need two more very expensive SRB Recovery ships.
Jim - 12/11/2006 2:58 PM"where a small stretch of special railroad " Too heavy for rails and too short of runs (turn radius problems)
"Very expensive SRB Recovery ships" - give me a break. If space program cannot afford buying two more tugboats, then we'd better stop pretending that we have space program at all"the issue is manning. Labor costs are the issue.
Jim - 13/11/2006 1:38 PMBaikonur trains never carried solids. Only unfueled vehicles. Shuttle is heavier than the N-1If you were have a railed vehicle, those curves are too sharp especially around the VAB. The switching would be too complex also
Now you know the problem of low launch rates. Skills have to be retained no matter what the flight rate is. (there are also union issue)
vda - 14/11/2006 3:18 PMOr rather, only turns around VAB are too sharp. But why on earth do you need to haul fully loaded stack around VAB? You don't need that. And if you don't need that, you can have rails only between VAB and launch pads. Everywhere else you use other means of transporting components.
vda - 14/11/2006 2:18 PMOr rather, only turns around VAB are too sharp. But why on earth do you need to haul fully loaded stack around VAB? You don't need that. And if you don't need that, you can have rails only between VAB and launch pads. Everywhere else you use other means of transporting components.
kraisee - 14/11/2006 10:08 PMActually the biggest problem isn't even the turns around LC-39 area. It's the gradient up to the Pads.Because the water table is so close to the surface in this area of Florida, the massive flame trench has to be above ground. That means the Pad must be above that, and the mobile launcher platform must somehow get above that.The Crawlers can climb the gradient. A locomotive on a rail would find extreme problems getting traction when pulling/pushing these sorts of loads.I've seen a study which demonstrates that even if the gradient were extended the three/four miles from the Pads all the way back to the VAB, it would still not be possible to move a Shuttle stack using four locomotives on four different rail lines (2 left of the flame trench, 2 right).LC-39 would basically have to be re-built from the ground up to support such an approach.Ross.
what about having a reel on pad and when the train comes to foot of that hill, they would attach a rope to the cart transporting rocket stack and with help of locomotives it gets up? just an idea
John Duncan - 18/11/2006 3:01 AMQuotewhat about having a reel on pad and when the train comes to foot of that hill, they would attach a rope to the cart transporting rocket stack and with help of locomotives it gets up? just an ideaThe issue would then be the forces pulling on the load...the MLP currently is held level by the crawler with huge jacks. You'd wind up pulling the MLP off the crawler or (most certainly) breaking the cables and wiping out everything within reach of the flying cables.
Avron - 18/11/2006 11:01 AMThis all goes away if you stack at the pad.. and move the assembly building out of the way... 4xSRB becomes a non issue... no more crawlers.. MLP etc... yes it costs to build said mobile structure.. but look at what is saved and what other options open up.. hell you could move the mobile structure from pad to pad... I would assume it would not be heavier than 2 SRB's.. and you could use rail .. anyone know waht it would cost to rebuild the RSS in todays money?
Jim - 19/11/2006 8:22 PMQuoteAvron - 18/11/2006 11:01 AMThis all goes away if you stack at the pad.. and move the assembly building out of the way... 4xSRB becomes a non issue... no more crawlers.. MLP etc... yes it costs to build said mobile structure.. but look at what is saved and what other options open up.. hell you could move the mobile structure from pad to pad... I would assume it would not be heavier than 2 SRB's.. and you could use rail .. anyone know waht it would cost to rebuild the RSS in todays money?The MST's at SLC-40 and SLC-37 weigh 11 and 14 million lbs respectively, These MST were/are for servicing not assembly. The one for the ARES V would be bigger. It would be 1/4 of the VAB (one high bay) and could not able move from the pad to pad . Your way is the "old" way like Delta II and Atlas II. The "new" way is what Saturn and Titan did and Shuttle, Atlas V and Delta IV are doing.
Avron - 22/11/2006 12:09 AM1/4 of the VAB.. so its large but empty.. not like there is any issues with lateral support.. if the whole STS stack can move so can a MST that is designed for assembly... it could be built in two parts i.e. 1/8 of the VAB that moves and you don't have to move both parts at the same time.. all that is needed is money.. and there seems to be more than enough to waste on projects like the ( name your favourite MSFC/NASA manned project)
TyMoore - 22/11/2006 9:20 AMI would also add that the flame trench and water deluge sound suppression systems would almost certainly be 'overloaded' by the jet blasts from a 4 SRB+Core LV. I used to think that it was more or less pretty easy to just hang a couple of extra SRB's off of an inline vehicle for extra thrust--but 4 segment SRB's are very heavy. A 5 segment SRB is even heavier (closer to 1.6-1.8 million pounds each.) By the time redesigns ripple throughout the system, you end up with almost a completely different vehicle (that may deceptively have the same moldline--but the changes are interior!) And the crawler/transporters are showing signs of age and wear--and spare parts are almost non-existant for them.An even larger vehicle may even overload the gravel beds of the crawler roads...which would require 'rebuilding' a good chunk of all of the launch infrastructure.So it would seem that in order to go bigger than CaLV would require assembling a fully liquid vehicle, with liquid boosters...It is difficult to create a new vehicle within the constraints of the existing infrastructure--thus I tend to think that CaLV is just about as big an LV as one can get without building a new VAB, new transporters, and a new Launch Complex--and that is a BIG chunk of change right there...not to mention the realestate needed...
TyMoore - 17/12/2006 8:26 AMWhat about overloading the crawler/transporters? Won't a MAX four, 4-segment SRB configuration vehicle exceed the maximum load carrying capability of these machines? (About 8 or 9 million pounds.)
TyMoore - 17/12/2006 2:25 PMI wasn't aware that NASA would replace the crawler transporters: it makes sense, though; the old ones are getting difficult to find parts for. Is there a link to the specs for the new machines?
TyMoore - 17/12/2006 7:26 AMWhat about overloading the crawler/transporters? Won't a MAX four, 4-segment SRB configuration vehicle exceed the maximum load carrying capability of these machines? (About 8 or 9 million pounds.)