And guess what: now CNES comes up and says dual-launch (on Ariane 5) is too expensive and Ariane 5 will loose it's competitiveness. And guess what: the replacement vehicle they come up with is a single-payload launcher.
The large, segmented solids certainly are a cost driver, especially for processing so getting rid of them may make sense but the core stages really don't look expensive to me.
@baldusi:But I still don't see how all there variants with multiple strapons etc. save cost.You can't have less than one engine. If that one engine is too expensive, find a way to make it cheaper but I strongly doubt that having a bit less power will save a lot. Using three of them will not really help, too. A core is a a core but it's pretty dumb stuff.
Going to horizontal processing: I don't believe that's going to save a lot of money. It will cause duplication of launch infrastructure and processes because there will always be payloads that require vertical integration so I'd guess going all-vertical as it is now is already cost effective.
My strong guess is that the cost structure for Ariane 5 is as it is right now because at that very level it's what makes all partners get as much out of it as possible, after all, they are still the market leader for comsat launches. Nobody is interested in Arianespace as an organization making money.
And CNES as it is is not interested in a sustained use of existing systems, they want to develop new stuff because otherwise they have almost no role in this anymore so whatever they propose must be as different from the status quo as possible.
SpaceX is a good thread to hold up for political agendas. They still have to launch their first comsat and then they'll have to get a track record and while they do all this, they'll have to see where they end up, cost wise. THAT will then be the time to think about what's coming next. I don't yet see where SpaceX is fundamentally cheaper. No matter how efficient your production line is, using 28 engines, three cores and four stages overall to launch a single large comsat is a lot of stuff to handle and produce.
"I don't say that with a sense of bravado but there's really no way for that vehicle to compete with Falcon 9 and Falcon Heavy. If I were in the position of Ariane, I would really push for an Ariane 6."
According to this Aviation Week article, CNES has dropped its opposition to a multi-engine LOX/LH2 core stage and to a solid first and second stage:CNES, ASI Favor Solid-Rocket Design For Ariane 6Previously they were insisting on a new staged combustion high thrust engine and claimed multi-engine solutions would be too expensive.
Quote from: pippinIf they are having issues with dual launches, why not just scale down? A smaller EPC, smaller boosters (maybe derived from the Vega program) and there you go with a single-launch architecture for which I don't really see why it can't be cost-competitive with SpaceX.Actually I thought about this too. "Just" reduce the size of core stage and boosters. I read that the Ariane 5 performance could be increased to 14-15t to GTO with filament casing for boosters, an improved Vulcain and the Ariane ME enhancements.So an 8t to GTO Ariane 6 with one stronger Vulcain and two smaller boosters (but still providing most of thrust and TVC) seems like a possible solution to me.
If they are having issues with dual launches, why not just scale down? A smaller EPC, smaller boosters (maybe derived from the Vega program) and there you go with a single-launch architecture for which I don't really see why it can't be cost-competitive with SpaceX.
You could dual launch smaller payloads. I'm not sure whether saving a few boosters for smaller payloads in more flexible designs is gonna have a big impact on costs. I read that even the big Ariane 5 boosters with TVC only make up 20-25% of the costs (is that correct?).
Regarding the strategic value of liquid engines, I don't think from a military point of view having liquid engine know-how is a must. The all solid launcher would probably be of more strategic value.
Ariane 5 was designed primarily for launching manned spacecraft. Hermes specifically. But right from the start the secondary design feature was lifting unmanned payloads such as comsats and science payloads. ESA was well aware that the primary requirement (lifting Hermes) would put Ariane 5 in the position that it would be WAY overpowered for launching single unmanned payloads. That was not regarded as a problem because the dual-launch concept already existed for quite some time. ESA figured the secondary role of Ariane 5 could be executed just fine by flying two payloads at the same time. With the demise of the Hermes project, the secondary role of Ariane 5 became the primary role.And here is another pointer to think about. The primary reason for ending the Ariane 4 was the fact that it's primary payloads (Comsats) were becoming so heavy that Ariane 4 was no longer capable of performing dual launches. Many of the later Ariane 4 launches carried single payloads, and as such, the cost of a single launch was no longer split between two customers, but came down on a single customer. Ariane 4 was becoming financially unattractive as a launcher because it was primarily becoming a single-payload launcher.And guess what: now CNES comes up and says dual-launch (on Ariane 5) is too expensive and Ariane 5 will loose it's competitiveness. And guess what: the replacement vehicle they come up with is a single-payload launcher.But that won't work, unless CNES manages to bring down the cost for such a launcher well below the Ariane 4 cost-level. And that will be one h*ll of a feat to accomplish.
And CNES as it is is not interested in a sustained use of existing systems, they want to develop new stuff because otherwise they have almost no role in this anymore so whatever they propose must be as different from the status quo as possible.SpaceX is a good thread to hold up for political agendas. They still have to launch their first comsat and then they'll have to get a track record and while they do all this, they'll have to see where they end up, cost wise. THAT will then be the time to think about what's coming next. I don't yet see where SpaceX is fundamentally cheaper. No matter how efficient your production line is, using 28 engines, three cores and four stages overall to launch a single large comsat is a lot of stuff to handle and produce.
So it seemed to a lot of engineers and decisionmakeres here, too. The cryogenic core and upper stages augmented by optional solid boosters were the favored design at ESA. But for development costs this would imply that you change all stages and the main engine, so you got to re-qualify all that.
Quote from: spacejulienSo it seemed to a lot of engineers and decisionmakeres here, too. The cryogenic core and upper stages augmented by optional solid boosters were the favored design at ESA. But for development costs this would imply that you change all stages and the main engine, so you got to re-qualify all that. But with optional boosters you need a HTE or at least two improved vulcains. I was thinking about one "slightly" improved vulcain and 2 boosters in basic configuration.
per booster, so multiply by two.
maybe they should go back to 4 viking engines then
Quote from: baldusi on 11/14/2012 12:03 pmAriane 5 is not cheap nos scalable. What's worse, sin the ECA lacks restar capability, for coast and restart missions you need the ES. Which means that's very inflexible and expensive. Quite reliable, though. But please remember, dual manifest is not a feature, is a defect.Wrong. It's a feature. Ariane 5 was designed primarily for launching manned spacecraft. Hermes specifically. But right from the start the secondary design feature was lifting unmanned payloads such as comsats and science payloads. ESA was well aware that the primary requirement (lifting Hermes) would put Ariane 5 in the position that it would be WAY overpowered for launching single unmanned payloads. That was not regarded as a problem because the dual-launch concept already existed for quite some time. ESA figured the secondary role of Ariane 5 could be executed just fine by flying two payloads at the same time. With the demise of the Hermes project, the secondary role of Ariane 5 became the primary role.And here is another pointer to think about. The primary reason for ending the Ariane 4 was the fact that it's primary payloads (Comsats) were becoming so heavy that Ariane 4 was no longer capable of performing dual launches. Many of the later Ariane 4 launches carried single payloads, and as such, the cost of a single launch was no longer split between two customers, but came down on a single customer. Ariane 4 was becoming financially unattractive as a launcher because it was primarily becoming a single-payload launcher.And guess what: now CNES comes up and says dual-launch (on Ariane 5) is too expensive and Ariane 5 will loose it's competitiveness. And guess what: the replacement vehicle they come up with is a single-payload launcher.But that won't work, unless CNES manages to bring down the cost for such a launcher well below the Ariane 4 cost-level. And that will be one h*ll of a feat to accomplish.
Ariane 5 is not cheap nos scalable. What's worse, sin the ECA lacks restar capability, for coast and restart missions you need the ES. Which means that's very inflexible and expensive. Quite reliable, though. But please remember, dual manifest is not a feature, is a defect.
That seems to be the latest ariane 6 proposal:http://www.esa.int/SPECIALS/Ministerial_Council_2012/SEMQQD72Q8H_mg_22_s_b.html
Quote from: Rugoz on 11/21/2012 12:35 pmThat seems to be the latest ariane 6 proposal:http://www.esa.int/SPECIALS/Ministerial_Council_2012/SEMQQD72Q8H_mg_22_s_b.htmlSo... Outboard solids are ground-started, then centre-line and second stage solids sequentially air-started? Finally, the hydrolox upper stage kicks in for orbital insertion and (if required) transfer orbit injection.