Quote from: Hyperion5 on 10/05/2014 06:39 pm1. Well I guess I should have expected nothing less from ULA in the larger DCSS not using the same tankage as the CBC. It's no wonder the Delta IV is so expensive given lack of commonality like that. 1. Unwarranted snark. ULA had nothing to do with the design of the DIV, it was Boeing. Also, What were you doing in the mid 90's? Where designing launch vehicles then or even now? Show me your resume on how many systems that you have designed and fielded in the last 15 years, much less cost effective ones.You have no insight into the design trades involved. They wanted "flatter" bulkheads to reduce stage length. Boeing tried to use CAIV in the design.
1. Well I guess I should have expected nothing less from ULA in the larger DCSS not using the same tankage as the CBC. It's no wonder the Delta IV is so expensive given lack of commonality like that.
Quote from: Hyperion5 on 10/05/2014 01:40 amTo be fair, I think a lot of people are factoring in Jim's statements about the Centaur stage being the most likely rather than pure performance. Myself? I felt that the ability to go to a single diameter would be very beneficial for keeping down build costs. I could be wrong however about the CBC & 5-meter DCSS being the same diameter though. The sources I can find note a .1 meter difference, which if true is really sad. In any case, it would allow you to trim down to a single PLF size, which shouldn't hurt even the playing field. They aren't building a new vehicle, just a new stage.The 5m DCSS does not use any of the same tankage as the core.The Atlas 5 m fairing is actually 5.2 and that has more usage.
To be fair, I think a lot of people are factoring in Jim's statements about the Centaur stage being the most likely rather than pure performance. Myself? I felt that the ability to go to a single diameter would be very beneficial for keeping down build costs. I could be wrong however about the CBC & 5-meter DCSS being the same diameter though. The sources I can find note a .1 meter difference, which if true is really sad. In any case, it would allow you to trim down to a single PLF size, which shouldn't hurt even the playing field.
A new first stage means it is a new launch vehicle. It is certainly not the Atlas V with a new first stage.Now they may call it the Atlas VI, or the Atlas V+, or the Blue Atlas, or the Atlas CH4, or whatever Marketing comes up with.But it won't be the same launch vehicle as before.
If they continue to use Centaur as their upper stage, that will make the fifth dramatically redesigned first stage to boost it to orbit, the original short SLV-3 Atlas, stretched Atlas II, Balloon tanked Russian engined Atlas III, current Atlas IV, and future Blue Origin powered AtlasX. The handles come and go, but the head of the hatchet seems to be staying the same.
Hmmmm....Little unexpected results.Especially, if to consider that in this case the option with continuous incert to orbit was considered (the single ignition of the upper stage).
Quote from: Llian Rhydderch on 10/06/2014 05:53 amA new first stage means it is a new launch vehicle. It is certainly not the Atlas V with a new first stage.Now they may call it the Atlas VI, or the Atlas V+, or the Blue Atlas, or the Atlas CH4, or whatever Marketing comes up with.But it won't be the same launch vehicle as before.It is that exactly, an Atlas V with a new first stage.Not being the same does not mean it is new.
Atlas V is to New Atlas as VW Beetle is to New Beetle.
The line of reason that "it's not a new rocket, just a new first stage" isn't making much sense to me. What needs to change before something is a new rocket? I feel like the argument has been pretty consistently the other way before now with the "rockets are not LEGO" argument.
I feel like the argument has been pretty consistently the other way before now with the "rockets are not LEGO" argument.
It is just simply because it is ULA. If it was SpaceX doing it, everyone with Jim first would scream about it being completely different, new, untested, ureliable vehicle.Just your good ol' double standard.
Quote from: Mader Levap on 10/07/2014 09:07 amIt is just simply because it is ULA. If it was SpaceX doing it, everyone with Jim first would scream about it being completely different, new, untested, ureliable vehicle.Just your good ol' double standard.Not a double standard. USAF and NASA will be involved with the development of the new stage, like all previous vehicles (see Titan IV). There was no such opportunity with Spacex.