SpaceX looks at Saturn V class

[Namechange User]

PurduesUSAFguy - 16/4/2007  11:21 PM

Developing a large engine that would allow them to build a single engine version of the Falcon 9 would make alot of sense, the potential HLV application aside.

Why?  From what I know of the Falc 9 part of the reliability estimates is based on it being a mult-engine vehicle.

[Avron]

OV-106 - 17/4/2007  12:21 AM

nacnud - 16/4/2007  7:07 PM

He does, the long term goal of SpaceX is to help make humanity a space faring civilization.  An F1 class engine would help in that goal.

Supposedly this is the case.  That's why I just don't get all the folks on here saying how wrong this company is, how it doen't understand what it takes, etc.

When he gets it right, he may end up shaking up the whole industry, and that is risky to a large number of people... I.e. don't shake the boat.

In terms of F1.. where is Tony?

[jongoff]

mong' - 16/4/2007  3:37 PM

Analyst - 16/4/2007  9:18 PM

They seem to have no idea of the magnitude of this effort. The technical problems, the schedule and the costs. Talking is cheap, to deliver is the hard part. Ask NASA, or the Russians, or anyone in the business.

Analyst

not to mention the total lack of any kind of market for a saturn V class LV

As much as I like SpaceX, I really hope they can get over their "BFR" fetish.  Making Falcon-I and IX into rock solid reliable boosters, then gradually adding reusability would be far more worthwhile than trying to build some huge heavy lift vehicle.  But we'll see.  Personally, I think Elon's smart enough that he'll figure it out at some point.

~Jon

[jongoff]

OV,

From what I know of the Falc 9 part of the reliability estimates is based on it being a mult-engine vehicle.

While this is generally true, you do hit a point of diminishing returns.  At some point adding extra engines increases the odds of some sort of common-mode failure that can take out the whole vehicle.  My personal preference is somewhere in the 4-6 range.  Enough that you can have one or two engines fail and still land the vehicle, but few enough that you don't end up with ridiculously complicated plumbing, and packaging.  

As a personal note that's semi-illustrative, the original strawman design concept MSS had for our XA-1.0 suborbital vehicle was going to have 12 engines--8 single axis vernier engines , and 4 fixed main engines.  The current concept has backed off to 5 engines--4 2-axis verniers (probably upscaled a tad from the size we currently have), and one central main engine (still fixed).  The combination still gets us all the features we wanted (engine out, "digital" throttling to reduce the needs for deep throttling, plenty of control authority), while greatly simplifying the vehicle, and probably increasing the mission reliability substantially.  Even if you can fly the whole mission with a single engine out, you're not really going to launch if one of the engines isn't working, so striking a balance between enough engines for safe redundancy, without going overboard is a must.

~Jon

[pippin]

OV-106 - 16/4/2007  6:23 AM

PurduesUSAFguy - 16/4/2007  11:21 PM

Developing a large engine that would allow them to build a single engine version of the Falcon 9 would make alot of sense, the potential HLV application aside.

Why?  From what I know of the Falc 9 part of the reliability estimates is based on it being a mult-engine vehicle.

Cost.

Read carefully. The article quoted EM, stating "IF we did a new engine, it would be in the F1 class", which makes perfect sense. They do have the small one, but putting 9 of them on the Falcon 9 has to hurt them on the cost side. So a single engine Falcon 9 is a logical step, isn't it?

Or what would you suppose? 2 Half size engines? Also no redundancy! 5 engines of 2 times Merlin size? It just does not make sense.

No, stick to the facts and it's a logical step, you would do the same.

[JIS]

pippin - 17/4/2007  1:20 PM

OV-106 - 16/4/2007  6:23 AM

PurduesUSAFguy - 16/4/2007  11:21 PM

Developing a large engine that would allow them to build a single engine version of the Falcon 9 would make alot of sense, the potential HLV application aside.

Why?  From what I know of the Falc 9 part of the reliability estimates is based on it being a mult-engine vehicle.

Cost.

Read carefully. The article quoted EM, stating "IF we did a new engine, it would be in the F1 class", which makes perfect sense. They do have the small one, but putting 9 of them on the Falcon 9 has to hurt them on the cost side. So a single engine Falcon 9 is a logical step, isn't it?

Or what would you suppose? 2 Half size engines? Also no redundance! 5 engines of 2 times Merlin size? It just does not make sense.

No, stick to the facts and it's a logical step, you would do the same.

Good point. However I wouldn't say that 9 engines on Falcon 1 could hurt them financially. Mass production of many small engines could be still cheaper than producing one much bigger. I think that the reason is that they have people developing Merlin who are not required now when the development is over.
I think that Musk should either sack them or find some job for them.

[aero313]

OV-106 - 17/4/2007  12:23 AM

Why?  From what I know of the Falc 9 part of the reliability estimates is based on it being a mult-engine vehicle.

Yup.  And Falcon 1 was supposed to be the most reliable launch vehicle in the history of space launch....

[pippin]

JIS - 16/4/2007  2:35 PM

pippin - 17/4/2007  1:20 PM

Cost.

Read carefully. The article quoted EM, stating "IF we did a new engine, it would be in the F1 class", which makes perfect sense. They do have the small one, but putting 9 of them on the Falcon 9 has to hurt them on the cost side. So a single engine Falcon 9 is a logical step, isn't it?

Or what would you suppose? 2 Half size engines? Also no redundance! 5 engines of 2 times Merlin size? It just does not make sense.

No, stick to the facts and it's a logical step, you would do the same.

Good point. However I wouldn't say that 9 engines on Falcon 1 could hurt them financially. Mass production of many small engines could be still cheaper than producing one much bigger. I think that the reason is that they have people developing Merlin who are not required now when the development is over.
I think that Musk should either sack them or find some job for them.

Also: Good point.

Does anyone out here have any hard facts about engine cost? I admit I have no clou on what you pay for a rocke engine. And what the fixed and variable costs are. Suspicion is: Most of the cost goes into development and qualification, variable cost into quality assurance. But then with 9 engines you have all these pipes and wires....

Any idea? How much is a Merlin-Size engine? And how much a, say, RD 171?

[simonbp]

aero313 - 17/4/2007  7:39 AM

Yup.  And Falcon 1 was supposed to be the most reliable launch vehicle in the history of space launch....

Sadly enough, in the history of alt.space it is, because they're the only ones so far to actually translate flashy graphics into a flown launch vehicle. Everybody else is jealous bastard with a paper rocket...

To go against the vibe here: and an F-1 class is stupid for any rocket SpaceX has designed, but they will probably develop one. A SpaceX F-1 (SF1) would be silly for a Falcon 9, considering they've already developed the Merlin-IC, and the SF1 would provide only a small amount of extra performance.

I do believe they can develop a SF1; these are the same group of engineers that developed the world's highest Isp gas generator LOX/Kerosene engine basically from scratch in three years, and then turned around and made a regen version in a single year. Given five years or so, it's not at unimaginable to think that could design a 1.5 Mlb class rocket. But why?

Because Elon wants to go to the moon. Griffin's mentioned commercial resupply of the lunar base, and I'm sure SpaceX will bid for that, but really, Musk's drive seems for real interplanetary exploration. You're not going anywhere without a lot of mass in LEO, and an SF1 is a ticket to allow SpaceX to do that. I don't think we've heard the last new vehicle/spacecraft announcement from Elon...

Simon

[Namechange User]

aero313 - 17/4/2007  7:39 AM

OV-106 - 17/4/2007  12:23 AM

Why?  From what I know of the Falc 9 part of the reliability estimates is based on it being a mult-engine vehicle.

Yup.  And Falcon 1 was supposed to be the most reliable launch vehicle in the history of space launch....

This reply illustrates my point from previous points exactly.  The internet is a wonderful tool for armchair quarterbacking and proclaiming to the world why everyone else is wrong.  The simple facts are SpaceX built a company, the tooling, the workforce, the procedures, engineered several engines and the rocket in a very short amount of time.  All with private funding.  That effort deserves nothing less than admiration and applause.  Did Falcon 1 have problems?  Sure.  Has it done well?  Yes, and test flights are to be exactly that.  Test flights, so you can test and fix those things that are not easily simulated or forseen when qualifying your hardware for flight.  

These type threads are also an excellent example of why so many companies out there building hardware are so secretive about their plans, timelines and business models.  Why subject yourself to second guess after second guess and posts like that above that simply declare offhand the Falcon 1 is a failure.  Is it possible that a self-made multi-millionare in his early or so 30's just may have a little more information than all of us on what he wants to do with HIS money and HIS business.  If successful, it will be for the better of this entire industry.  I for one wish him all the luck I can, because unlike some or many on here, I do understand what I'm talking about and how this business does work.

[stockman]

Well said! I agree 100%. I too get tired of all the naysayers who sound more jealous of people like Elon Musk and can do nothing but trash what his is attempting to do. I admire SpaceX for no other reason than they are will to take a risk to move forward. At least he is flying h/w and not just drawing pretty pictures of what they want to build.

[Jim]

OV-106 - 17/4/2007  9:56 AM
I for one wish him all the luck I can, because unlike some or many on here, I do understand what I'm talking about and how this business does work.

Then you should see that there are issues and if you don't then you don't know the "business" works

[Namechange User]

Well Jim, you and I have had our differences in the past.  Of course there are issues and I believe I have made that clear and every company, every project has them.  Based on posts of the past, I would expect you to know this as well.  It does not mean they are doomed to failure and the company should just close the doors now.  If there were none, that would be unusual and interesting topic of conversation.  Not this "lets bash them BS".  It does not mean they are doomed to failure.  

So let me ask you what the issues are since you imply you know everything about company and every project out there.  Please, enlighten me.....

[aero313]

OV-106 - 17/4/2007  9:56 AM

aero313 - 17/4/2007  7:39 AM

OV-106 - 17/4/2007  12:23 AM

Why?  From what I know of the Falc 9 part of the reliability estimates is based on it being a mult-engine vehicle.

Yup.  And Falcon 1 was supposed to be the most reliable launch vehicle in the history of space launch....

This reply illustrates my point from previous points exactly.  The internet is a wonderful tool for armchair quarterbacking and proclaiming to the world why everyone else is wrong.

It's also a wonderful tool for those of us who have actually developed and launched brand new vehicles and successfully put paying satellites in orbit.

The simple facts are SpaceX built a company, the tooling, the workforce, the procedures, engineered several engines and the rocket in a very short amount of time.  All with private funding.

And as I've said in the past, contrary to what the cheerleaders here and elsewhere seem to think, SpaceX is not unique in this accomplishment.  Others have successfully developed launch systems with less money on a shorter schedule.  This isn't bashing SpaceX, just documenting history.

As I've also said in the past, I agree that from a technical standpoint SpaceX has made a significant accomplishment.  My frustration is with the inexperienced cheerleaders who are too naive to understand the hard parts of successfully executing a mission.  It's these details that add significantly to cost.  Every new company that wants to develop a new rocket produces unrealistic cost estimates because they don't know about (or purposely overlook) the real-world problems that can and do occur.  The reason why existing launch vehicles cost what they do (at least in part) is because of the need to account for and accommodate these costs.  

You (and others) seem to be quick to dismiss the experienced people on this forum.  We're not bashing SpaceX.  We're trying to point out reality.  The Futron reliability study had so many flaws that it wasn't even funny.  Other spin from SpaceX isn't helping their credibility with customers that really have money.

[nacnud]

[pippin]

aero313 - 16/4/2007  6:05 PM

My frustration is with the inexperienced cheerleaders who are too naive to understand the hard parts of successfully executing a mission.  

Stay cool. The purpose of a cheerleader is to look good. You need them for entertainment. Boring without. Let'em have fun. You don't want a band of grave diggers at your game...

[pippin]

And by the way... We are talking a lot about costs here... Anybody able to answer my question posted before (engine costs)? Just to get this back on a somewhat more serious track...

[jcanal12]

Speaking of larger engines, it might be a typo but the F9 page has the Merlin vacuum thrust at 155,400 lbf.

[josh_simonson]

In talking about the Falcon 1 and Falcon 9, SpaceX points out that the two most 'reliable' designs are a single engine rocket, like the Falcon 1, that's very simple with the minimum number of things to go wrong, and a rocket with redundant systems such as the Falcon 9 which is fault tolerant.

At some point it will become very difficult to get a Merlin 1 based rocket off the ground because one of the 27 (or more) engines will be likely to trip an alarm when it fires up, much llike happened on this last launch.  History was unkind to the N-1, which also took the route of massive engine clusters.

However, Elon is probably going to wait until he see's how the Merlin 1/2Cs work together on the F9 before pitching headlong into another engine development project.  If the test firing this fall shakes the stage apart, we may see a new engine development project shortly thereafter.

[Danderman]

rumble - 16/4/2007  9:13 PM  Just think what sort of interest a zenit-class rocket for 1/2 zenit cost (guessing,
totally) would generate...

The Falcon IX already costs more than a Zenit-2, so a bigger rocket would likely cost more than Zenit.