My original thought was that Falcon-X and XX must refer to "Raptor 9" and "Raptor Heavy," referring to upscaled Falcon9 and Falcon Heavy configurations utilizing the new Raptor engines. (Nomenclature from this thread: http://forum.nasaspaceflight.com/index.php?topic=30103.msg1041121#msg1041121 )But did I catch this right that 39A and Shiloh are indeed an interest to SpaceX for something only beyond the 10 year time frame from now? If Raptor Heavy estimates put it above 200mt to LEO, could Falcon X and XX actually be something larger? Good god!
Raptor is an engine, not a stage. It's a follow on the the Merlin Family.MCT (term SpaceX has recently used for the vehicle we assume is the same as the older renders of a Falcon XX), is to be a Methane fueled Raptor powered wide body HLV. I have seen nothing beyond speculation about the MCT having a single and multiple core configuration like the Falcon Family.
Would it not make sense to start with a requirement? We assume any BFR is for Mars. I see no reason to waste money on something without a detailed Mars architecture. What would it really require and cost, initially and ongoing? The numbers thrown around are staggering. SpaceX does not have that much money, and there are no costumers for BFR. As long as Elon's fortune is tied up with his "Other" companies I can't see this happening in the next 3-5 years. Anyway, SpX really should not talk about it until they are successful in the V1.1 and FH. We assume Elon has a detailed Mars plan, but we don't what it is. We know Elon says he needs at least 150mT for Mars and methane is his preferred fuel. We know a little about Raptor. We don't know about landing and hab modules. I also worry about re-usability. If re-usability cuts performance by 50-80 percent of expendable, then any BFR would have to be a Super Duper Ginormous BFR. Let's say he would need around 400mT expendable. I don't see how you can do that practically without F1 class performance, something Raptor is not.
I also worry about re-usability. If re-usability cuts performance by 50-80 percent of expendable, then any BFR would have to be a Super Duper Ginormous BFR. Let's say he would need around 400mT expendable. I don't see how you can do that practically without F1 class performance, something Raptor is not.
We assume Elon has a detailed Mars plan, but we don't what it is. We know Elon says he needs at least 150mT for Mars and methane is his preferred fuel. We know a little about Raptor. We don't know about landing and hab modules.
without F1 class performance, something Raptor is not.
Raptor is an engine, not a stage. It's a follow on the the Merlin Family.
Quote from: QuantumG on 05/20/2013 12:39 amQuote from: SpacexULA on 05/20/2013 12:21 amSingle Stage to orbit requires unobtainable materials/fuels and even then is not optimal.Wrong, and optimal for what?Getting objects into LEO. Seen very few SSTO proposals that didn't require to date unobtained efficiency to get even small payloads to LEO.QuantumG, before you smack me around more than anything I am pointing out Elon Musk himself at one point said SSTO was not practice, so I am more talking about SpaceX than something like Skylon.
Quote from: SpacexULA on 05/20/2013 12:21 amSingle Stage to orbit requires unobtainable materials/fuels and even then is not optimal.Wrong, and optimal for what?
Single Stage to orbit requires unobtainable materials/fuels and even then is not optimal.
OK, show of hands: is MCT just a synonym for BFR/Falcon XX or, is it more akin to (for lack of a better example) a KISS version of NAUTILUS-X?
I vote for the second, obviously. Here's the relevant interview excerpt:Go to the 4:25 mark.
Quote from: CriX on 05/20/2013 05:32 pmI vote for the second, obviously. Here's the relevant interview excerpt:Go to the 4:25 mark.I don't think it's entirely clear if MCT is a spacecraft or something "attached" to a spacecraft. Maybe it's a thruster? (Mars Cycler Thruster?)
Imagine a large, 3-core rocket configuration using 27 Raptor Engines (Akin to Falcon Heavy). This would lift probably >200mt. Would this not qualify as Falcon XX? If you wanted this "Raptor Heavy" fully reusable, what mass to orbit penalty would it incur. Half? 100mt to LEO and full reusability! That would still be amazing.I suppose if reusability is the end goal of ALL SpaceX rocket systems then you might need a 400mt class rocket to get 200mt to orbit and your rocket safely re-parked on the pad. Perhaps that is what Falcon X and XX would be.
Quote from: GalacticIntruder on 05/20/2013 04:31 pmwithout F1 class performance, something Raptor is not. I got the impression that Raptor has F1 class performance.
Quote from: Joel on 05/20/2013 05:01 pmQuote from: GalacticIntruder on 05/20/2013 04:31 pmwithout F1 class performance, something Raptor is not. I got the impression that Raptor has F1 class performance.Hmm, depends on your definition of class! Raptor is about 650,000 lbf vs 1.5M for F1.
Performance is not the same as class. If three Raptors = 1.95M lbf has the about the same capability with its better ISP and similar T/W. I would say it has F1 class performance. 5 * 1.5M = 7.5M @ ISP 263 s9 * 0.65M = 5.85M @ ISP 380 s (May be Vacuum performance, so it may be a little high)