Quote from: strangequark on 06/07/2009 01:35 amUseable Post-Ascent propellant for J-246 is 99,896 kg. LEO Payload for D-IVH is 22,560 kg. I'd say about 4 or 5. Numbers listed are for 130nmi, 29 deg and 220nmi, 28.7 deg circular orbits for the Jupiter and Delta respectively, so take that into account.On this same vein...I'm sure this has already been explored by the direct team, but I am curious.Currently, the base line for a moon shot is 2 J-246's. They are working on launching the CSM and LSAM on a J-130, so they only need one JUS for the mission. Makes sense. Then, with a propellent depot, Direct can launch the whole CSM/LSAM/JUS (unfueled) stack on a single J-246, for rendezvous with the depot, fueling up, and going to the moon.But, before there is a dept, could you launch the depot-dependent stack, and have it rendezvous with a fuel tank launched on a J-130 with an OMS sytem. This way, your docking is a little simpler, as the stack stays in tack, and you are just doing a fueling docking. Then ullage motors de-orbit the tank and the stack heads off to TLI.<snipped>In effect, the J-130 would launch a sinlge use "propellent depot", which would basically be a JUS with an OMS, rear docking ring, ullage motor, and less engines.
Useable Post-Ascent propellant for J-246 is 99,896 kg. LEO Payload for D-IVH is 22,560 kg. I'd say about 4 or 5. Numbers listed are for 130nmi, 29 deg and 220nmi, 28.7 deg circular orbits for the Jupiter and Delta respectively, so take that into account.
Quote from: adamsmith on 06/08/2009 07:17 pm1. reply to 1: Maybe2. reply to 2: Correct that is why this is a phase 4 item that NASA does not have to pay for until proven by events.3. Why Falcon 9 first stage? It is already planned to be a booster to Falcon 9 heavy in an arrangement similar to the Jupiter Core.1. Not maybe, it is too many2. NASA would still have to pay for the mods to the F9 which would be like a new vehicle. It isn't plug and play. 3. No they are not in a similar arrangment. The SRB's lift from the top and liquid boosters lift from the bottom. But also, Atlas V or Delta IV cores can be used as boosters. Delta IV has demonstrated it. So again, why F9? Atlas V or Delta IV cores exist and are operating.
1. reply to 1: Maybe2. reply to 2: Correct that is why this is a phase 4 item that NASA does not have to pay for until proven by events.3. Why Falcon 9 first stage? It is already planned to be a booster to Falcon 9 heavy in an arrangement similar to the Jupiter Core.
FWIW, I am impressed by the ability to Direct 3.0 to function well with or without propellant depots, which is a vital characteristic (IMHO) as we do not know how long it shall take to deploy propellant depots.As soon as depots come on-line, Direct 3.0 transitions and begins to realize substantial leverage and yet in the meantime NASA can still perform interesting and useful missions beyond LEO as we await depot development and deployment.And of course, the Direct 3.0 budget charts leave money for depot work, something ESAS does not. In contrast, an all EELV/COTS approach leaves us trapped in LEO until depots come on-line.
I am impressed by the ability to Direct 3.0 to function well with or without propellant depots, which is a vital characteristic (IMHO) as we do not know how long it shall take to deploy propellant depots.
reply to 1: I agree to disagree.
Ross,From the MLAS Thread about the problems with the current Ares I LAS:QuoteI got a little more info on this. The concern is primarily based around the potential of a large SRB exploding. It's a small risk, but still exists.I understand that one of the more likely failure modes in this class of "exploding SRB's" would be if a fairly large chunk of propellant ever came away inside the booster during flight and blocked the nozzle exit -- the resulting overpressure inside the booster would make for a very spectacular explosion with lots of heavy steel case fragments flying in every direction -- potentially some towards the Orion.<snipped>It sounds like this is an issue inherent to all vehicles using SRBs, not just Ares I. Does Jupiter protect against these failure modes? As was hinted at the end, with the extra performance Jupiter allows, I assume it would be possible to beef-up the boost protection cover that protects the vehicle during launch.
I got a little more info on this. The concern is primarily based around the potential of a large SRB exploding. It's a small risk, but still exists.I understand that one of the more likely failure modes in this class of "exploding SRB's" would be if a fairly large chunk of propellant ever came away inside the booster during flight and blocked the nozzle exit -- the resulting overpressure inside the booster would make for a very spectacular explosion with lots of heavy steel case fragments flying in every direction -- potentially some towards the Orion.<snipped>
Quote from: adamsmith on 06/08/2009 09:04 pmreply to 1: I agree to disagree.I know it is too many, it is not an opinion
Quote from: gladiator1332 on 06/08/2009 03:08 pmRoss,From the MLAS Thread about the problems with the current Ares I LAS:QuoteI got a little more info on this. The concern is primarily based around the potential of a large SRB exploding. It's a small risk, but still exists.I understand that one of the more likely failure modes in this class of "exploding SRB's" would be if a fairly large chunk of propellant ever came away inside the booster during flight and blocked the nozzle exit -- the resulting overpressure inside the booster would make for a very spectacular explosion with lots of heavy steel case fragments flying in every direction -- potentially some towards the Orion.<snipped>It sounds like this is an issue inherent to all vehicles using SRBs, not just Ares I. Does Jupiter protect against these failure modes? As was hinted at the end, with the extra performance Jupiter allows, I assume it would be possible to beef-up the boost protection cover that protects the vehicle during launch.I hesitate to mention this (just way too obvious). A pressure relief valve isn't possible?Is it just that it would be a big development programme?cheers, Martin
Quote from: Lobo on 06/08/2009 06:36 pmQuote from: strangequark on 06/07/2009 01:35 amQuote from: Gregori on 06/07/2009 12:48 amA quick question:Roughly how many EELV's flights would be required to top up the Depot with enough propellant for a solo J246 Lunar Mission?(lets say our EELV is a Delta IV Heavy)Useable Post-Ascent propellant for J-246 is 99,896 kg. LEO Payload for D-IVH is 22,560 kg. I'd say about 4 or 5. Numbers listed are for 130nmi, 29 deg and 220nmi, 28.7 deg circular orbits for the Jupiter and Delta respectively, so take that into account.Wow, that many?How do 4-5 D4H flights stack up against a single J130 (assuming a J130 could get into a circularized LEo orbit for dockign with teh depot) cost wise?Seems like it still might be cheaper To just use a 2nd Jupiter.4 or 5 assumes 100% of the EELV's payload would be usable prop delivered to the depot. This is, of course, not even close to the case. You still need a spacecraft, it needs its own propellant and you still need the tank and the means of transfer. I think you'd be lucky if 2/3 of the LEO payload ended up being prop transferred to the depot. So count more like 6 or 8. I can't see how in the world that could be cheaper than one Jupiter.This is why the depot-filled-by-smaller-vehicles thing still doesn't make any sense to me.
Quote from: strangequark on 06/07/2009 01:35 amQuote from: Gregori on 06/07/2009 12:48 amA quick question:Roughly how many EELV's flights would be required to top up the Depot with enough propellant for a solo J246 Lunar Mission?(lets say our EELV is a Delta IV Heavy)Useable Post-Ascent propellant for J-246 is 99,896 kg. LEO Payload for D-IVH is 22,560 kg. I'd say about 4 or 5. Numbers listed are for 130nmi, 29 deg and 220nmi, 28.7 deg circular orbits for the Jupiter and Delta respectively, so take that into account.Wow, that many?How do 4-5 D4H flights stack up against a single J130 (assuming a J130 could get into a circularized LEo orbit for dockign with teh depot) cost wise?Seems like it still might be cheaper To just use a 2nd Jupiter.
Quote from: Gregori on 06/07/2009 12:48 amA quick question:Roughly how many EELV's flights would be required to top up the Depot with enough propellant for a solo J246 Lunar Mission?(lets say our EELV is a Delta IV Heavy)Useable Post-Ascent propellant for J-246 is 99,896 kg. LEO Payload for D-IVH is 22,560 kg. I'd say about 4 or 5. Numbers listed are for 130nmi, 29 deg and 220nmi, 28.7 deg circular orbits for the Jupiter and Delta respectively, so take that into account.
A quick question:Roughly how many EELV's flights would be required to top up the Depot with enough propellant for a solo J246 Lunar Mission?(lets say our EELV is a Delta IV Heavy)
Look, back in the 60's they were evaluating Saturn I configurations with 4 UA 1207 solid rocket boosters each one of which is loosely comparable to a Falcon 9 first stage by thrust and size. So I think I'll stand by my earlier statement and let the passage of time decide the issue.
Quote from: adamsmith on 06/08/2009 10:42 pmLook, back in the 60's they were evaluating Saturn I configurations with 4 UA 1207 solid rocket boosters each one of which is loosely comparable to a Falcon 9 first stage by thrust and size. So I think I'll stand by my earlier statement and let the passage of time decide the issue.Do you work in the business? You don't need to cite history. I didn't say it couldn't be done. I said it would cost too much to be worth it because the changes to the vehicle and infrastructure are massive. Those Saturn I vehicle configurations were not chosen because of the same thing. But back then, there were deeper pockets and sky was the limit.Rockets are not Legos. Falcon 9 as a Direct strap on is a non starter. a. SRB's are a must. Direct is a SDLV and therefore requires solidsB. The F9 can not connect to a shuttle ET. C. Spacex is not a sub contractor to others. They do not provide hardware to others contractors.
Of course, with that and unlike them, you'll have to "show your work". That is one of the down sides of coming from outside of the establishment.
Quote from: mars.is.wet on 06/08/2009 05:17 pmOf course, with that and unlike them, you'll have to "show your work". That is one of the down sides of coming from outside of the establishment.I'm confused. Does the Ares camp in NASA not have to "show their work"? Are they free to make any claims they want about performance, cost and schedule without the basis of the claims not being open for scrutiny?
Quote from: Crispy on 06/08/2009 12:34 pmno no no! jupiter and jupiter light. the 130 is the special case.but I think ross is right. for this panel, technical naming convention is not a problemI stand corrected. makes perfect sense in a foward looking architecture, the JL is done to provide a bridge until COTSD and manratedEELVs can service most LEO demands. Jproper is to facilitate the lunar component of the VSE. And later maybe a Jupiter Heavy can be whipped up from the ideas that went into Ares V, VII or X or whatever its upto now (:So Jupiter130 = Jupiter LightJupiter2XX = Jupiter
no no no! jupiter and jupiter light. the 130 is the special case.but I think ross is right. for this panel, technical naming convention is not a problem
The real utility of the propellant depot is in allowing higher flight rates and greater numbers of annual missions than the initial two-launch mission profile, given NASA's exploration budget and existing KSC launch facilities and MSFC, ATK, and P&W manufacturing facilities.Try these "notational" numbers:Jupiter #1 = $300 millionSpacecraft on Jupiter #1 = $300 millionJupiter #2 = $300 millionPropellant delivered to KSC: $3 millionTotal Cost: $903 million, all paid by NASA.Limited to perhaps 6 missions per year (12 J-232 launches)vs.Jupiter #1 = $300 millionSpacecraft on Jupiter #1 = $300 millionPropellant delivered to Kazakhstan or French Guiana: $3 millionSoyuz for propellant delivery = $75 million * 5 = $375 millionTotal Cost: $978 million (pretty much a wash).But $378 million paid by international partners in exchange for a seat on the mission, leaving $600 million to be paid by NASA. Enables perhaps 9-12 missions per year.
Soyuz for propellant delivery = $75 million * 5 = $375 million
Hmm, try it the other way around.Start with the existing 2x J-246 architecture. The downside of this (the attraction of using J-130 CLV) is that ~15mT of CLV launch capacity remains unused because of limited fuel in the EDS. This is fantastic margin for the early flights.However, once the standard 2-launch is mature, ~15mT of extra EDS fuel would be able to fully optimise this architecture:-1) Launch J-246 EDS. (Current plan).2) Launch a single EELV fuel tanker with maybe 20mT of fuel, rendezvous immediately, and top up the EDS. Thru-TLI mass is now approaching 100mT.3) Once the EDS is safely re-fuelled, launch a fully-loaded J-246, which can now be pushed through TLI with loads of margin to spare.3a) This can also be used to augment a single-Jupiter cargo mission. A 20mT fuel boost would give a substantial increase in single-Jupiter thru-TLI mass. (Not the full ~10mT, due to the mass of PT hardware, and not being able to fly a direct-injection profile).<snipped>
PS -- Here is a quick teaser for the new cards (same data as the last set, but slightly updated logo's and the "heavy" variants are coming too).