Author Topic: SpaceX: Mars Colonial Transporter "MCT" -- Speculation (not Raptor)  (Read 652429 times)

Offline QuantumG

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yeesh.  That's a technicalities.   No metal bending, but "studies" - which means study something specific, not just wish for a result.

It's an argument over nothing.  I'm out.

"Studies" was my word. SpaceX didn't even say they were studying it yet.

That's how much of a non-story this is.
Human spaceflight is basically just LARPing now.

Offline modemeagle

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Here is a design I came up with.
*Based on very little data!!!
That's why it's called "Speculation" :)

I note that the lite version went above the 5 g acceleration limit you have imposed on your other simulations. If that is a SpaceX limit it will probably apply to this vehicle, too.
Good catch Aero, I set it at 10 when I was trying different engine combinations which allowed me to quickly move through the design.  I fixed it and also added another scale to the drawing.

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By the way, I know I have to allow opinion, be it one of my own articles or someone elses, but the writer actually posted on here (when he didn't have to) so I want people to be at least polite!
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Offline KelvinZero

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yeesh.  That's a technicalities.   No metal bending, but "studies" - which means study something specific, not just wish for a result.

It's an argument over nothing.  I'm out.

"Studies" was my word. SpaceX didn't even say they were studying it yet.

That's how much of a non-story this is.

Sometimes it is not the comment, it is the context.

I think this illustrates the current context quite nicely: http://hhgproject.org/entries/carelesstalk.html  8)

Offline peter-b

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Quite frankly, the author of the article appears to have pulled together a bunch bits and pieces of otherwise-unrelated small talk and commentary to come to an overall conclusion that seems tenuous, at best. While I really do appreciate his willingness to come on to the NSF forums to defend his article, I'm afraid that I honestly don't consider it to be the finest example of good reporting.

SpaceX have never before been reticent about announcing new projects well in advance of beginning the experiments to validate that the projects are even possible. Their R&D folks have enough on their plate at the moment (Merlin 1D and F9 production ramp-up, FH, Grasshopper, F9R) without adding yet another launch system to the mix -- especially when, unlike their other offerings, that hypothetical launch system has no clear multi-customer business case in the foreseeable future. As I said earlier in this thread, I will remain profoundly sceptical that this "MCT" concept exists as a project until I hear something official from SpaceX directly.
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Offline starbase1

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Hmmm...

It all sounds logical to me.

F9 Heavy has 27 engines, is that really a good idea? (Cough, N1, Cough).

Seems to me that is as far as you can go with the existing technology, and we know he wants to get price down. So to me it makes sense to look at new engines, which can be applied in a variety of configurations, which are more robust, efficient, reusable, cheaper, pick any combination.

So shoot for something which has all the advantages above, and scales better for large launches.  The start of a new family, with the long term goal of replacing the current family, with a seriously heavy lifting top end model as an optional configuration.

If someone with the money bites, bolt the bits together from the smaller options, and launch the big one.

As for customers, once you have the launch capability to fire off something like a proven ISS model, with a years worth of air and packed lunches,  a flight out to Mars (minus landing) starts to look very easy indeed. Hell, swing past Venus on the way home, like the old Soviet plan.

Elon gets to ride along and visit two worlds!


 

Offline peter-b

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F9 Heavy has 27 engines, is that really a good idea? (Cough, N1, Cough).

I believe that it has been repeatedly explained, over and over again, that you cannot infer anything at all about whether or not multiple engines are a good idea or not from the (abbreviated) flight history of the N1.
Research Scientist (Sensors), Sharp Laboratories of Europe, UK

Offline ZachMild

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To clarify a little further,
-The article is culled from two on-the-record interviews. Gwynne Shotwell briefly mentioned the possibility of a huge new rocket during an NSS presentation (and some scattered public references in other places) but the info, numbers and quotes came from the interviews. This is not speculation, small talk or rumor.
-I believe MCT describes the engine, not the whole LV.
-SpaceX is studying it, not cutting metal (as far as I know), and no timeframes were given (nor was money much discussed). In April Gwynne said they have not finalised the architecture, and Musk did not say otherwise.
-I am not sure how dedicated SpaceX is to this particular LV, but Musk said they were doing this engine instead of the Merlin 2...

Piece is pretty thin, I know, but the company declined to answer followup questions and I didn't want to wait 1-3yrs for better info. I'm a little surprised Musk mentioned it to me at all.

As above, my email address is [email protected] I don't mind if you don't think the articles are interesting or useful, you can criticize them as harshly as you like (please CC me as well), I've heard worse (and not all unjustified). The possibility of spreading inaccuracies keeps me up at night, so anyone reading, if I've written something wrong then for god's sake please tell me.

Offline baldusi

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Hi guys, I wrote the article. I'll be happy to speak to any problems you have with it, or anything else I write. You can vent directly in the future. My email address is [email protected]
I appreciate you posting here. Thank you! That's the sort of interaction I like.
I do recall Elon stating that for whatever system he had in mind for a Mars transport, he said that you could expect the "boosters" to show their Dragon inheritance, but the rest of the vehicle to be quite different from anything SpaceX has shown so far.

Offline dcporter

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+2 (haHA) to Zach posting here, good show. I'll restate QG's criticisms but nicely: a lot of the vitriol here would have been avoided if your "who said what when to whom" rundown had been clearer.

Offline aero

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Back to speculating on the MCT and the fuel for it.

Fuel was quoted as "Not RP-1." What other choices are there for the first stage of a launch vehicle? I don't see LH2/LOX as being a good choice due to the huge and massive tanks needed and neither does Hypergolics seem appropriate. And I don't invision SpaceX breaking new ground by developing an engine and fuel combination that doesn't have substantial history behind it.

My Google search turned up one Soviet fuel, c10h16, but there is little information about it and it is not generally available.
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Offline dcporter

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This has been discussed extensively, and the consensus was that Musk's previous comments on "light hydrocarbons" (e.g. methane) were very pertinent. Ideas included pure methane, as well as some denser mixtures involving methane and other light hydrocarbons. That's all I remember.

Offline Halidon

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To clarify a little further,
-The article is culled from two on-the-record interviews. Gwynne Shotwell briefly mentioned the possibility of a huge new rocket during an NSS presentation (and some scattered public references in other places) but the info, numbers and quotes came from the interviews. This is not speculation, small talk or rumor.
-I believe MCT describes the engine, not the whole LV.
-SpaceX is studying it, not cutting metal (as far as I know), and no timeframes were given (nor was money much discussed). In April Gwynne said they have not finalised the architecture, and Musk did not say otherwise.
-I am not sure how dedicated SpaceX is to this particular LV, but Musk said they were doing this engine instead of the Merlin 2...

Piece is pretty thin, I know, but the company declined to answer followup questions and I didn't want to wait 1-3yrs for better info. I'm a little surprised Musk mentioned it to me at all.

As above, my email address is [email protected] I don't mind if you don't think the articles are interesting or useful, you can criticize them as harshly as you like (please CC me as well), I've heard worse (and not all unjustified). The possibility of spreading inaccuracies keeps me up at night, so anyone reading, if I've written something wrong then for god's sake please tell me.

Thanks for coming on NSF to talk, Zach! Elon and Ms. Shotwell have talked bigger motors and bigger rockets before, I think the single biggest news items in your piece are that they won't be doing a Merlin-2 as in a scaled-up Merlin-1 and won't be using RP-1. Whatever form MCT takes, they're having to break out from the Merlin family and that's a big step.

The bit about MCT being the engine specifically is interesting as well, wish Elon had given you at least one of those words though ;D

Offline sanman

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It seems like "conventional wisdom" can run in any direction.
Some say "haste makes waste" while others say "time and tide wait for no man"

Some might say that SpaceX should build on what they know, and others will say that they have to break out of the box. How is it possible to know what's the optimal route to pick? Seems like the only way to know is through a post-mortem analysis after the fact.

Offline mrmandias

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Thanks for this clarification.  I appreciate it.

To clarify a little further,

snipped

« Last Edit: 10/17/2012 09:16 pm by mrmandias »

Offline FinalFrontier

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Wonder if the new engine would be Methane/LOX. And if that would be staged or gas gen.
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Offline RocketmanUS

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Speculation

I don't think it will be Hydrogen based on the information given.

X-33 Rockwell proposal.
http://www.dfrc.nasa.gov/gallery/photo/X-33/HTML/EC96-43631-5.html
They were to use a dense fuel, what was it and it's specs?

Offline GalacticIntruder

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If indeed they are seriously trying a methane powered BFR on their own dime, as their next gen rocket; I would be worried.

SpaceX is not a large defense/space contractor and they do not have the resources to spend on major R&D. I am surprised they would seriously attempt million pound class alt fuel engine this early. Maybe in ten years. It would be wiser to cut a deal with NG/TRW for a TR106 RP1 first stage and develop hydrolox Raptor upper stage and a 5m-6m core, larger fairing.

Musk said during the 2011 FH press conference he had a small NASA contract, to study a 150mT class rocket. He/SpX also has said they  need such a BFR to get to Mars. He also said the FH will be upgraded over time. 

No doubt some type of BFR is in their future, but methane powered BFR does not seem plausible anytime soon.
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Offline QuantumG

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Musk said during the 2011 FH press conference he had a small NASA contract, to study a 150mT class rocket.

http://www.nasa.gov/home/hqnews/2010/nov/HQ_10-292_Heavy_Lift.html

Maximum individual contract award of $625,000. Almost two years ago.
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Offline Lobo

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Alright.  Without linking to prior discussions on this forum:  I suspect that it is methane, will be reusable, and having that much excess upmass will enable recovery of pretty much any upperstage.  The crossfeeding heavy version of it won't be for a good long while but will be planned for, it will be constructed very close to the pad or perhaps to water, 15 meter diameter more likely than "7", heavy version will double as a hypersonic transport booster for the rich someday, heavy version will send tens of thousands of people to Mars, it will have at least 5 engines per core, it will be cheaper than EELV's of today per launch (not including payload), and 99% of you will doubt all of these points I suggest.

If it's going to be a first stage engine, then what about propane instead of methane?  It's far easier to keep liquid than methane.  If it's a first stage engine to launch from earth, and the point isn't to harvest methane from the Martian atmosphere, then what are the advantages of methane over RP-1?  ISP isn't as much of a concern on the first stage engine.  I don't know much about using propane as a rocket propellant, but I'd think it'd be similar to methane, but easier to handle and store in liquid form. 

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