Author Topic: DIRECT v2.0 - Thread 3  (Read 1123309 times)

Offline robertross

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Re: DIRECT v2.0 - Thread 3
« Reply #180 on: 01/16/2009 01:58 pm »
Ah it's in the February issue! I was looking all over the newsstands for it, but it's not yet out.

You can find it in some places.   I know people were able to pick copies up last Friday in Providence CT, Seattle WA and Washington DC, so its 'out there' already.

Ross.

It was in Canada (Nova Scotia) at Chapters last week. To me, that means all the USA and Canada should have it ...lol  ;)
FYI, Nova Scotia seems to have a reputation of being behind the times, but maybe we need to think twice about that.

I'm so happy to have that article/issue in my 'collection'.  :)

Offline Kaputnik

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Re: DIRECT v2.0 - Thread 3
« Reply #181 on: 01/16/2009 04:15 pm »
Will,
I think you're starting to nit-pick a bit now. Like you, I used to sceptical about the JUS, but with the backing of Kutter I am no longer worried.
However I do think that you may have a point about the economics of the JUS, especially if it requires very delicate handling.

My other outstanding concern is that the per-unit cost for a J120 still seems too close to that of an Ares-I for a vehicle which is around twice the size. YMMV.
"I don't care what anything was DESIGNED to do, I care about what it CAN do"- Gene Kranz

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #182 on: 01/16/2009 04:16 pm »


Quote
If Bernard Kutter says the mass estimate for the JUS is reasonable, I give that opinion considerable respect. I still have to ask what the production cost penalty is for a common bulkhead design , since Boeing has rejected that alternative in spite of the obvious payload benefit on the Delta IV. Also, if pressurization is required at any point prior to launch for a Centaur derived JUS, since that has been such a fundamental feature of the Centaur design to date.

There is a higher cost during the testing phase of the development program, to ensure the common bulkhead design is stable (anyone recall the S-II common bulkhead which 'inverted' during testing?).   But it is quite marginal compared to the total development expenditure (<1%).

In production though, the materials and labor cost is actually LESS because it deletes all of the intricate hardware items which make-up the Intertank area.   Manufacturing costs can actually be cut by between 10-20% by utilizing a common bulkhead design instead of a separate-bulkhead, though again, compared to the total development cost this is pretty small.

Ross.


I don't think that is correct. The 2007 GAO report on Ares specifically mentions the higher manufacturing cost of common bulkhead designs, a solution the Ares I US was reluctantly forced into to meet its mass goals. As further evidence I can point to the S-II stage, which cost significantly more to produce than the much larger first stage. And to the decision of the H-2 design team to abandon an operational common bulkhead US and produce a new intertank design. That decision would be inexplicable if they didn't expect manufacturing savings.

Boeing takes a significant payload hit by not using a common bulkhead on the Delta-IV US. Unless they're incompetent designers, they have to be avoiding some pretty significant life cycle costs.

« Last Edit: 01/16/2009 04:36 pm by Will »

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #183 on: 01/16/2009 04:28 pm »
Also, I still want to know why the Direct team think they can develop their EDS for significantly less than NASA's, considering that it's larger, more complex, and needs to absorb the cost of J-2 development.

Offline Ronsmytheiii

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Re: DIRECT v2.0 - Thread 3
« Reply #184 on: 01/16/2009 04:31 pm »

Offline clongton

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Re: DIRECT v2.0 - Thread 3
« Reply #185 on: 01/16/2009 04:40 pm »


Quote
To note that Lockheed hasn't flown a structurally stable  hydrogen powered upper stage in decades isn't a criticism of Mr. Kutter. They just weren't able to close the business case.

Actually that isn't correct.   Lockheed-Martin build the Shuttle External Tanks, which are the largest structurally stable hydrogen tanking structure in the world today.   To say they don't have experience with such systems is therefore incorrect -- they actually have experience with one of the most challenging of such systems.

Ross.

The ET isn't a full stage, and if it was it wouldn't be an upper stage, since the engines it fuels start on the pad. It doesn't use a common bulkhead and it was designed decades ago.

Will,
I’m almost twice Ross’s age and have a lot less tolerance for BS than he does, so let me just cut to the chase here.

The ET isn’t a “stage” only in the sense that the engines and avionics are not attached to the tank proper. STS is a unique design configuration, unlike anything else in the world, but it still is comprised of all the same rocket elements. It’s still a stage – the 1st one. But if you look at the tank structure, and consider the tank structure of any other “stage”, you will get a feel for what Ross was trying to get across to you. Next to having reliable engines, the most difficult part of any stage is the propellant tank. It’s not just a pressurized gas bottle like folks have connected to the back of their house.

Doesn’t use a common bulkhead and was designed decades ago? These are non-qualifications for something being a stage? OMG. I’m amazed. I never knew that. Thank you. That will forever change my perspective on stage design. BTW, What did they call those upper thingmes with no common bulkheads on the rockets they launched people on decades ago?

As for your comment about when the engines are started, that just is out there. Every rocket I know of has a “First Stage” with engines that are started on the pad. Come-on. Quit looking for gotchas and join the discussion.

BTW. Do you know a guy named JIS?

Quote
Granted, there have been more recent tweeks, but they don't constitute new stage designs.

Your use of the word “tweeks” in that context is revealing. It displays a lack of knowledge beyond the superficial of what the real differences are between your grandfather’s Centaur and the one flying today. The design differences are most decidedly not “tweeks”. I suggest you ask your friends at LM to bring you up to date.

Quote
Also, I still want to know why the Direct team think they can develop their EDS for significantly less than NASA's, considering that it's larger, more complex, and needs to absorb the cost of J-2 development.

Simple; because we worked with the industry that has been doing it for 45 years knows what it’s doing and NASA doesn’t have a clue on how to design this kind of a stage. Short and to the point.
« Last Edit: 01/16/2009 04:47 pm by clongton »
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline mjcrsmith

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Re: DIRECT v2.0 - Thread 3
« Reply #186 on: 01/16/2009 04:42 pm »


That is just way too cool!!!!!

Great Job!

Offline mrbliss

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Re: DIRECT v2.0 - Thread 3
« Reply #187 on: 01/16/2009 04:52 pm »
  [image of J130 (?) model built from LEGO]

How cute!  And she's reading NASA.gov! ;)

Too bad Lego's never made those round bricks & cylinders in orange. Although they have shown up in brown from time to time.

Anyway, looks good!

Steve

Offline bad_astra

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Re: DIRECT v2.0 - Thread 3
« Reply #188 on: 01/16/2009 04:53 pm »
Just wanted to say the PM article is excellent. Friends of mine are already borrowing my copy and I want it back.
"Contact Light" -Buzz Aldrin

Offline clongton

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Re: DIRECT v2.0 - Thread 3
« Reply #189 on: 01/16/2009 04:55 pm »
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #190 on: 01/16/2009 05:26 pm »

Quote
Also, I still want to know why the Direct team think they can develop their EDS for significantly less than NASA's, considering that it's larger, more complex, and needs to absorb the cost of J-2 development.

Simple; because we worked with the industry that has been doing it for 45 years knows what it’s doing and NASA doesn’t have a clue on how to design this kind of a stage. Short and to the point.


With Ares NASA picks a design, does a detailed review of it and hands it to the contractors to execute, then  oversees their work and adds their overhead to the project. If they decide they like your upper stage design and want to use it, the same things happens, yes? So where do the savings in executing the EDS project come from allowing it to absorb the J-2 development and still cost less?

Offline Ronsmytheiii

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Re: DIRECT v2.0 - Thread 3
« Reply #191 on: 01/16/2009 05:30 pm »
Upclose view of the RS-68's, which are former car exhausts:
« Last Edit: 01/16/2009 05:31 pm by Ronsmytheiii »

Offline Jim

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Re: DIRECT v2.0 - Thread 3
« Reply #192 on: 01/16/2009 05:34 pm »
If they decide they like your upper stage design and want to use it, the same things happens, yes?

no

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #193 on: 01/16/2009 05:40 pm »


Quote
To note that Lockheed hasn't flown a structurally stable  hydrogen powered upper stage in decades isn't a criticism of Mr. Kutter. They just weren't able to close the business case.

Actually that isn't correct.   Lockheed-Martin build the Shuttle External Tanks, which are the largest structurally stable hydrogen tanking structure in the world today.   To say they don't have experience with such systems is therefore incorrect -- they actually have experience with one of the most challenging of such systems.

Ross.

The ET isn't a full stage, and if it was it wouldn't be an upper stage, since the engines it fuels start on the pad. It doesn't use a common bulkhead and it was designed decades ago.

Will,
I’m almost twice Ross’s age and have a lot less tolerance for BS than he does, so let me just cut to the chase here.


OK, that was nit-picking on my part. I retract it.

Offline Eerie

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Re: DIRECT v2.0 - Thread 3
« Reply #194 on: 01/16/2009 05:41 pm »
I have this theoretical question: if you were to optimize Jupiter-120, could you reach Constellation goals with 3 launches of it?

Offline clongton

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Re: DIRECT v2.0 - Thread 3
« Reply #195 on: 01/16/2009 05:44 pm »

With Ares NASA picks a design, does a detailed review of it and hands it to the contractors to execute,

That's the way it used to be, but not under Mike Griffin.
Under his leadership, NASA is not "picking a design and doing a detailed review of it". They are doing the actual detail design using designers that have never done it before with no design input from the contractors with the experience. Don't get me wrong, these are smart designers, among the best in the world. But there is design and there is design. What Griffin has done is similar to taking a bunch of exceptionally good jet fighter aircraft designers, putting them in a room behind locked doors and telling them to design a nuclear-powered submarine. They don't know how. Will they come up with a working design? Yes. Will it be anywhere near as technically good and cost efficient as what they could get from industry directly? Not a snowball's chance in hell.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #196 on: 01/16/2009 05:46 pm »
I have this theoretical question: if you were to optimize Jupiter-120, could you reach Constellation goals with 3 launches of it?

You need to build an EDS anyway. Why not use it for an upper stage?

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #197 on: 01/16/2009 05:49 pm »

With Ares NASA picks a design, does a detailed review of it and hands it to the contractors to execute,

That's the way it used to be, but not under Mike Griffin.
Under his leadership, NASA is not "picking a design and doing a detailed review of it". They are doing the actual detail design using designers that have never done it before with no design input from the contractors with the experience. Don't get me wrong, these are smart designers, among the best in the world. But there is design and there is design. What Griffin has done is similar to taking a bunch of exceptionally good jet fighter aircraft designers, putting them in a room behind locked doors and telling them to design a nuclear-powered submarine. They don't know how. Will they come up with a working design? Yes. Will it be anywhere near as technically good and cost efficient as what they could get from industry directly? Not a snowball's chance in hell.

And why would they stop doing that just because they chose to build Direct?

Offline Jim

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Re: DIRECT v2.0 - Thread 3
« Reply #198 on: 01/16/2009 05:59 pm »

And why would they stop doing that just because they chose to build Direct?

Because it isn't working and LM is the ET expert

Offline clongton

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Re: DIRECT v2.0 - Thread 3
« Reply #199 on: 01/16/2009 06:09 pm »

And why would they stop doing that just because they chose to build Direct?

Because it isn't working and LM is the ET expert

And the one man who insisted it be done that way will no longer be there.
« Last Edit: 01/16/2009 06:10 pm by clongton »
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

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