Author Topic: Griffin speech - EELV would not work for Constellation  (Read 32473 times)

Online Chris Bergin

http://www.nasa.gov/pdf/208916main_Space_Transportation_Association_22_Jan_08.pdf

Here's the part that will make many a coffee be spat over screens in Denver etc. ;)

Once the rationale for this particular dual-launch EOR scenario is understood, the next question is, logically, “why don’t we use the existing EELV fleet for the smaller launch?”  I’m sure you will understand when I tell you that I get this question all the time.  And frankly, it’s a logical question.  I started with that premise myself, some years back.  To cut to the chase, it will work – as long as you are willing to define “Orion” as that vehicle which can fit on top of an EELV.  Unfortunately, we can’t do that.  

The adoption of the shuttle-derived approach of Ares I, with a new lox/hydrogen upper stage on a reusable solid rocket booster (RSRB) first stage, has been one of our more controversial decisions.  The Ares V heavy-lift design, with its external-tank-derived core stage augmented by two RSRBs and a new Earth departure stage (EDS), has been less controversial, but still not without its detractors.  So let me go into a bit of detail concerning our rationale for the Shuttle-derived approach.  

The principal factors we considered were the desired lift capacity, the comparative reliability, and the development and life-cycle costs of competing approaches.  Performance, risk, and cost – I’m sure you are shocked.

The Ares I lift requirement is 20.3 mT for the ISS mission and 23.3 mT for the lunar mission.  EELV lift capacity for both the Delta IV and Atlas V are insufficient, so a new RL-10 powered upper stage would be required, similar to the J-2X based upper stage for Ares I.  We considered using additional strap-on solid rocket boosters to increase EELV performance, but such clustering lowers overall reliability.

It is also important to consider the growth path to heavy lift capability which results from the choice of a particular launch vehicle family.  Again, we are designing an architecture, not a point solution for access to LEO.  To grow significantly beyond today’s EELV family for lunar missions requires essentially a “clean sheet of paper” design, whereas the Ares V design makes extensive use of existing elements, or straightforward modifications of existing elements, which are also common to Ares I.  

Next up for consideration are mission reliability and crew risk.  EELVs were not originally designed to carry astronauts, and various human-rating improvements are required to do so.  Significant upgrades to the Atlas V core stage are necessary, and abort from the Delta IV exceeds allowable g-loads.  In the end, the probabilistic risk assessment (PRA) derived during ESAS indicated that the Shuttle-derived Ares I was almost twice as safe as that of a human-rated EELV.  

Finally, we considered both development and full life cycle costs.  I cannot go into the details of this analysis in a speech, and in any case much of it involves proprietary data.  We have shared the complete analysis with the DoD, various White House staff offices, CBO, GAO, and our Congressional oversight committees.  Our analysis showed that for the combined crew and heavy-lift launch vehicles, the development cost of an EELV-derived architecture is almost 25% higher than that of the Shuttle-derived approach.  The recurring cost of the heavy-lift Ares V is substantially less than competing approaches, and the recurring cost of an EELV upgraded to meet CEV requirements is, at best, comparable to that for Ares I.  All independent cost analyses have been in agreement with these conclusions.  

So, while we might wish that “off the shelf” EELVs could be easily and cheaply modified to meet NASA’s human spaceflight requirements, the data says otherwise.  Careful analysis showed EELV-derived solutions meeting our performance requirements to be less safe, less reliable, and more costly than the Shuttle-derived Ares I and Ares V.

Now is a good time to recall that all of the trades discussed above assumed the use of a production version of the Space Shuttle Main Engine (SSME).  But, returning to a point I made earlier, we continued our system analysis following the architecture definition of ESAS, looking for refinements to enhance performance and reduce risk and cost.  We decided for Ares I to make an early transition to the 5-segment RSRB, and to eliminate the SSME in favor of the J-2X on the upper stage.  Similarly, elimination of the SSME in favor of an upgraded version of the USAF-developed RS-68 engine for the Ares V core stage, with the EDS powered by the J-2X, offered numerous benefits.  These changes yielded several billion dollars in life-cycle cost savings over our earlier estimates, and foster the use of a common RS-68 core engine line for DoD, civil, and commercial users.  

Praise is tough to come by in Washington, so I was particularly pleased with the comment about our decision on the 5-segment RSRB and J-2X engine in the recent GAO review:  “NASA has taken steps toward making sound investment decisions for Ares I.”  Just for balance, of course, the GAO also provided some other comments.  So, for the record, let me acknowledge on behalf of the entire Constellation team that, yes, we do realize that there remain “challenging knowledge gaps”, as the GAO so quaintly phrased it, between system concepts today and hardware on the pad tomorrow.  Really.  We do.  

Offline clongton

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RE: Griffin speech - EELV would not work for Constellation
« Reply #1 on: 01/23/2008 04:54 PM »
Wow, that's quite a mouthful there. Thanks Chris. BTW, that's one of the fastest times I've seen recently for getting a speach available in its entirety. Thanks.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline stockman

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RE: Griffin speech - EELV would not work for Constellation
« Reply #2 on: 01/23/2008 05:11 PM »
Quote
The Bush Administration has made no decision on the end date for ISS operations.  We are, of course, concerned that Station operating costs after 2016 will detract from our next major milestone, returning to the Moon by 2020.  But while the budget does not presently allocate funds for operating ISS beyond 2016, we are taking no action to preclude it.  Decisions regarding U.S. participation in ISS operations after 2016 can only be made by a future Administration and a future Congress.  I am sure these will be based on discussions with our international partners, progress toward our Exploration goals, utility of this national laboratory, and the affordability of projected ISS operations.  Again, we plan to keep our commitments to our partners, utilizing ISS if it makes sense.
 


I found this paragraph interesting in regards to ISS... it appears that 2016 retirement is FAR from a done thing after all. Yes some holes are left open for future governments to make but this makes it clear that continued operation is merely a decision or two from reality. Good news for those that want to see this multi-year project actually used for something and for some time into the future.
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Offline Mark Max Q

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Re: Griffin speech - EELV would not work for Constellation
« Reply #3 on: 01/23/2008 05:19 PM »
"So, while we might wish that “off the shelf” EELVs could be easily and cheaply modified to meet NASA’s human spaceflight requirements, the data says otherwise. Careful analysis showed EELV-derived solutions meeting our performance requirements to be less safe, less reliable, and more costly than the Shuttle-derived Ares I and Ares V."

Would love to hear what the EELV folks think of that.

Offline Ronsmytheiii

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Re: Griffin speech - EELV would not work for Constellation
« Reply #4 on: 01/23/2008 05:38 PM »
Quote
Mark Max Q - 23/1/2008  1:19 PM

"So, while we might wish that “off the shelf” EELVs could be easily and cheaply modified to meet NASA’s human spaceflight requirements, the data says otherwise. Careful analysis showed EELV-derived solutions meeting our performance requirements to be less safe, less reliable, and more costly than the Shuttle-derived Ares I and Ares V."

Would love to hear what the EELV folks think of that.

I think that they would say that the early performance issues that were used to disqualify EELV in this way are now disappearing while Ares I is being developed.
"Every vision is a joke until the first man accomplishes it; once realized, it becomes commonplace." - Robert Goddard

Offline meiza

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Re: Griffin speech - EELV would not work for Constellation
« Reply #5 on: 01/23/2008 05:38 PM »
And the Delta IV abort gee overloads...

Offline Antares

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Re: Griffin speech - EELV would not work for Constellation
« Reply #6 on: 01/23/2008 05:46 PM »
Mikey said
Quote
while we might wish that “off the shelf” EELVs could be easily and cheaply modified to meet NASA’s human spaceflight requirements, the data says otherwise.
Sing with me!:
"When you own the information, you can bend it all you want."  (John Mayer.)

It's kinda funny that 2.5 years after ESAS, he's still having to sell the architecture.  By now, one would think it could stand on its own merits.
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #7 on: 01/23/2008 05:53 PM »
Quote
Antares - 23/1/2008  1:46 PM

Sing with me!:
"When you own the information, you can bend it all you want."  (John Mayer.)
Nah. Mickey would'nt do that would he? Hey Mickey!
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Norm Hartnett

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RE: Griffin speech - EELV would not work for Constellation
« Reply #8 on: 01/23/2008 06:30 PM »
This speech is one of the reasons I respect Dr. Griffin. The man can really put together a good speech and this year he has done several of them. I still consider him one of the most dynamic leaders NASA has ever had.

I would like to challenge both the DIRECT group and the EELV group to respond to this speech on a point-by-point basis.

Not with cheap one-liners or with criticism of his solutions to the guidelines laid out by law but with a cohesive well reasoned response.

If you can respond to this speech in the tone with which it was presented I think you can go a long, long way to furthering your goal of encouraging the adoption of your solutions.

Good luck.
“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline edkyle99

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RE: Griffin speech - EELV would not work for Constellation
« Reply #9 on: 01/23/2008 06:31 PM »
Wow indeed.  A landmark presentation for the Constellation archive, but an odd one.  Griffin sounds both convincing, decisive, and paranoid-defensive all at once.  

I see the most important theme here as follows.  Griffin thinks he is building an architecture to go to Mars, not to ISS or even to the Moon really.  (Never mind that Congress just zeroed the Mars budget!)  

The Ares/Orion architecture will look better cost-wise than any alternative under the assumption that it will be used for Mars.  But what if it is not used for Mars?  

 - Ed Kyle

Offline kevin-rf

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Re: Griffin speech - EELV would not work for Constellation
« Reply #10 on: 01/23/2008 06:42 PM »
Noticed he said nothing about the five segment thrust oscillation issues that are ranked very high. You know something along the lines of no launcher development is trouble free and we are addressing them (provides examples of the thrust oscillation).

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Offline Jorge

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RE: Griffin speech - EELV would not work for Constellation
« Reply #11 on: 01/23/2008 06:42 PM »
Quote
stockman - 23/1/2008  12:11 PM

Quote
The Bush Administration has made no decision on the end date for ISS operations.  We are, of course, concerned that Station operating costs after 2016 will detract from our next major milestone, returning to the Moon by 2020.  But while the budget does not presently allocate funds for operating ISS beyond 2016, we are taking no action to preclude it.  Decisions regarding U.S. participation in ISS operations after 2016 can only be made by a future Administration and a future Congress.  I am sure these will be based on discussions with our international partners, progress toward our Exploration goals, utility of this national laboratory, and the affordability of projected ISS operations.  Again, we plan to keep our commitments to our partners, utilizing ISS if it makes sense.
 


I found this paragraph interesting in regards to ISS... it appears that 2016 retirement is FAR from a done thing after all.

It never was a done deal.

People saw the lack of funding allocation after 2016 and jumped to their own conclusions.
JRF

Offline Danny Dot

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RE: Griffin speech - EELV would not work for Constellation
« Reply #12 on: 01/23/2008 06:44 PM »
Quote
Chris Bergin - 23/1/2008  11:30 AM

http://www.nasa.gov/pdf/208916main_Space_Transportation_Association_22_Jan_08.pdf

Here's the part that will make many a coffee be spat over screens in Denver etc. ;)

snip

... and abort from the Delta IV exceeds allowable g-loads.  

snip

What is it going to take to make NASA stop saying this lie?  Boeing/Delta solved this problem within 24 hours of being told the standard Delta profiles were too high.

Danny Deger
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Offline Thomas

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Re: Griffin speech - EELV would not work for Constellation
« Reply #13 on: 01/23/2008 06:46 PM »
I'm glad to see Griffin emphasizing that the switch to the 5 segment booster/J-2X upper stage was for the purposes of reducing the cost/development time of the Ares V and not due to any inherent weakness in the SRB or SSME. Too many Ares I detractors either don't realize this or intentionally mislead their audience. I have no problems with criticizing the Ares I design assuming you a) actually know something about real rockets, and b) you don't twist the facts for your own purposes.

Also nice to hear him emphasize that the point of Constellation is not to get a CEV, any CEV, into LEO, its to develop an architecture that can progress toward a permanent lunar outpost, a mars mission and NEO mission. I'm not an engineer but those who are have convinced me that EELV's just don't have the growth potential.

Offline savuporo

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RE: Griffin speech - EELV would not work for Constellation
« Reply #14 on: 01/23/2008 06:55 PM »
Ok, one really needs to read the entire speech, to see where the big gaping holes are. It appears that the "common sense" that Griffin tries to invoke isnt all that common, and his mars mania shines through as well.

EDIT: holy moly, im only halfway through and it gets better and better. We finally got the answer on where did the four-crew to lunar surface requirement for Constellation came from. Apparently it was a "General Agreement". Anyone met this evasive General in person?

EDIT2: OMG, its full of stars.  Basically, the entire ESAS architecture just got justified by hydrogen boiloff ( which, apparently is some fundamental constant of our universe like value of Pi or Planck constant )
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Offline Norm Hartnett

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RE: Griffin speech - EELV would not work for Constellation
« Reply #15 on: 01/23/2008 06:57 PM »
Quote
edkyle99 - 23/1/2008  11:31 AM

I see the most important theme here as follows.  Griffin thinks he is building an architecture to go to Mars, not to ISS or even to the Moon really.  (Never mind that Congress just zeroed the Mars budget!)  

The Ares/Orion architecture will look better cost-wise than any alternative under the assumption that it will be used for Mars.  But what if it is not used for Mars?  

-   Ed Kyle

I disagree with you on both of the above points.

Griffin stated in the portion of his speech dealing with the mandates of the President and Congress that; “Now, returning to our space architecture, note the order of primacy in requirements. We are not primarily building a system to replace the Shuttle for access to LEO, and upgrading it later for lunar return. Instead, we are directed to build a system to "carry astronauts beyond our orbit to other worlds", but which can be put to the service of the ISS if needed. In brief, we are designing for the Moon and beyond.”

Not the Moon and not Mars but beyond, in other words a system that has the versatility to go to any place in space that is reasonable within the framework of the next thirty years.

As to the Constellation architecture looking better cost-wise than any alternative for Mars IMO Ross has already addressed this in the DIRECT discussion. And to address your question, if it is not used for Mars there are still the NEOs, Mars' moons, and Venus.
“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline Jim

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Re: Griffin speech - EELV would not work for Constellation
« Reply #16 on: 01/23/2008 07:02 PM »
Quote
Thomas - 23/1/2008  2:46 PM

I'm glad to see Griffin emphasizing that the switch to the 5 segment booster/J-2X upper stage was for the purposes of reducing the cost/development time of the Ares V and not due to any inherent weakness in the SRB or SSME..

That is after spin.  

Ares V was to use the SSME also.   The change was due to issues with airstarting the SSME and making it expendable.  Sound like a weakness to me

Offline clongton

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RE: Griffin speech - EELV would not work for Constellation
« Reply #17 on: 01/23/2008 07:13 PM »
Quote
edkyle99 - 23/1/2008  2:31 PM

I see the most important theme here as follows.  Griffin thinks he is building an architecture to go to Mars, not to ISS or even to the Moon really.  (Never mind that Congress just zeroed the Mars budget!)
 - Ed Kyle
In defense of Mike (am I really doing this?) Mars was explicitly called for in the original mandate of the VSE. Choosing to create a launch system that would enable Mars missions and then use it "also" for the moon is a reasonable approach. It prevents creating new capability for the Mars mission when its turn comes around.
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Offline yinzer

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Re: Griffin speech - EELV would not work for Constellation
« Reply #18 on: 01/23/2008 07:16 PM »
When the switch to the five-segment and J-2X was announced, they specifically said that air-starting the SSME was one of the top two risks identified by the ESAS.  You can see the charts here.
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Offline Norm Hartnett

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Re: Griffin speech - EELV would not work for Constellation
« Reply #19 on: 01/23/2008 07:17 PM »
Quote
Jim - 23/1/2008  12:02 PM

Quote
Thomas - 23/1/2008  2:46 PM

I'm glad to see Griffin emphasizing that the switch to the 5 segment booster/J-2X upper stage was for the purposes of reducing the cost/development time of the Ares V and not due to any inherent weakness in the SRB or SSME..

That is after spin.  

Ares V was to use the SSME also.   The change was due to issues with airstarting the SSME and making it expendable.  Sound like a weakness to me

Something of a chicken and egg problem here. I heard about the air starting SSME problem long before I heard about how cost effective the J-2X was going to be but... as to which came first?

“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline jongoff

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RE: Griffin speech - EELV would not work for Constellation
« Reply #20 on: 01/23/2008 07:18 PM »

Norm,

Quote
I would like to challenge both the DIRECT group and the EELV group to respond to this speech on a point-by-point basis.

As I'm at work at the moment, I need to keep this short.  Also, I'm not really in either the EELV or DIRECT groups (though I've got friends in both camps), even though it may sound like it at times.

I'd like to comment on just one thing first (from page 17, emphasis mine).  This was one of the main rationales Griffin gave for rejecting a two launch technique which used equal sized launchers (ie DIRECT):

But if we split the EOR lunar architecture into two equal but smaller vehicles, we will need ten or more launches to obtain the same Mars-bound payload in LEO, and that is without assuming any loss of packaging efficiency for the launch of smaller payloads. When we consider that maybe half the Mars mission mass in LEO is liquid hydrogen, and if we understand that the control of hydrogen boiloff in space is one of the key limiting technologies for deep space exploration, the need to conduct fewer rather than more launches to LEO for early Mars missions becomes glaringly apparent.

While one could definitely draw the conclusion that Griffin drew, ie. that hydrogen boiloff issues imply it would be better to launch the system in fewer pieces, one could also draw a different conclusion.  The conclusion I would draw is that if cryogenic propellant storage technologies are so critical--develop them.  Don't let the existing state of the art in propellant handling drive transportation system decisions for projects that won't be undertaken for 15-20 years!  

There are current technologies under development that could yield very low to zero boiloff of cryogenic propellants.  For a six launch architecture, especially if the LH2 is being used in some sort of nuclear or solar thermal system (where the hydrogen is used gradually over the course of the trip to and from Mars), you already need a system that can keep LH2 for months to years, so extending that technology further so that boiloff during mission assembly isn't an issue.

Is 2025-2030 really so close that we can't afford to do this right and actually develop the technologies we need instead of trying to kludge by with existing technologies? 

Once you have the boiloff issue reduced or solved, that ~500klb of hydrogen ceases to be a headache, and begins to be an opportunity.  That's a lot of demand for propellant in orbit, and it can be supplied commercially.  You're already going to need propellant transfer technologies anyway if you have to launch the hydrogen in multiple launches, so what's to stop launching it in even smaller launches?  Use a depot if you're worried about too many docking events with your mars ship. 

I'm sure the DIRECT guys can bring up other points, but that's one that stuck out to me.  If one of his key arguments for why you need Ares V is hydrogen boiloff, he's going about it in the wrong way.

~Jon


Offline texas_space

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RE: Griffin speech - EELV would not work for Constellation
« Reply #21 on: 01/23/2008 07:26 PM »
Jon may have something here.  Propellant boiloff is an issue, but it does scream out as a problem to be solved by a new technology or strategy and not by a new and expensive hulking rocket.  Griffin does seem to assume that technology for various things including propellant storage will remain static.  Without money they may remain static anyway, but if there's no money then it's a moot point IMO.

Personally, I'm convinced that nuclear propulsion will be needed to really go to Mars (and keep going back).  Unless a reactor or its components can't be broken down into smaller components (wise anyway from a safety standpoint), then that couldn't be used as a justification for a heavy lift vehicle either.
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Offline savuporo

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RE: Griffin speech - EELV would not work for Constellation
« Reply #22 on: 01/23/2008 07:28 PM »
Quote
jongoff - 23/1/2008  10:18 AM
the control of hydrogen boiloff in space is one of the key limiting technologies for deep space exploration, the need to conduct fewer rather than more launches to LEO for early Mars missions becomes glaringly apparent.

While one could definitely draw the conclusion that Griffin drew, ie. that hydrogen boiloff issues imply it would be better to launch the system in fewer pieces, one could also draw a different conclusion.  

Exactly. Either deal with the boiloff problem or dont use hydrogen. Justifying a multibillion decades long project, launchers and basically every other technical decision in the program with something so trivial and obviously solvable .. he calls himself an engineer ?

And thats by far not the only "logical" conclusion drawn in his speech that just does not click.
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Offline Thomas

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Re: Griffin speech - EELV would not work for Constellation
« Reply #23 on: 01/23/2008 07:33 PM »
The SSME airstart issue was not a "problem" or a "weakness". Everyone knew that the SSME as designed was not air-startable. Turning it into an air-startable engine would take time and money--again everyone knew this from the get go. What the 5 segment SRB + J-2x solution did was allow more money to go towards eventual Ares V hardware and less into turning the SSME into a second stage engine. Since the Ares V has been identified as essential to Constellation and beyond it seems like a good trade off to me anyway

Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #24 on: 01/23/2008 07:33 PM »
Quote
Thomas - 23/1/2008  2:46 PM

I'm glad to see Griffin emphasizing that the switch to the 5 segment booster/J-2X upper stage was for the purposes of reducing the cost/development time of the Ares V and not due to any inherent weakness in the SRB or SSME. Too many Ares I detractors either don't realize this or intentionally mislead their audience.

The following is a small portion of what was written by me, in concert with the rest of the DIRECT team, in the Summer 2007 issue of Horizons. You are new to posting (don’t know how long you’ve been reading) so you may not be aware that we have been constantly stating this, over and over again, for the past almost 2 years now. We go out of our way to make sure that we present the facts as they actually are and do not ever intentionally mislead anyone. We don't have to because the facts speak for themselves. When we have discovered that we have misspoken we have gone back to the thread(s) and corrected our mistakes, in plain view.

{begin quote}
Theoretically, the Ares-I / Ares-V launch concept is a good idea. Too often missed in the conversations of pro and con for Ares-I is the Saturn-V class heavy lift vehicle for the Moon and Mars. Crewed missions to the Moon and Mars are mandated in the VSE, but bringing such an expensive new launch vehicle online in today’s economic and political climate would prove to be extremely difficult at best. To his credit, the new administrator of NASA, Dr. Michael Griffin, together with other notables, was able to devise an architecture that enabled this lifter, while addressing the additional VSE requirements of a Shuttle replacement and continued servicing of the ISS. The solution was the pair of Ares launch vehicles, where a small launcher, constructed almost entirely of active and flight-proven hardware, is deployed to replace the crew transport functions of Shuttle and provide service to the ISS, and at the same time, to be the financial stalking horse for the flight articles needed for the heavy lift. The Ares-V would be too expensive to navigate Congressional authorization by itself, but if some of its development costs could be shared by a second, less expensive vehicle that addressed the immediate need to replace Shuttle and service the ISS, then the heavy lifter drops into the realm of the affordable. Thus was the Ares 1.5 launch concept born. It was a good idea.
{end quote}

The entire article is located here:
http://www.aiaa-houston.org/newsletter/aug07/aug07.pdf
The entire issue is a good read. I would recommend getting all of the issues as they come out. They are all, every one, good reads.

Returning you now to Mike's speech.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Tim S

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RE: Griffin speech - EELV would not work for Constellation
« Reply #25 on: 01/23/2008 07:39 PM »
Well said Mr Griffin.

We're not talking about U-Haulers for cargo here. We're talking manned space flight.

EELV folks on here need to stick to what they know.

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RE: Griffin speech - EELV would not work for Constellation
« Reply #26 on: 01/23/2008 07:43 PM »
Texas Space,
Quote
Jon may have something here.  Propellant boiloff is an issue, but it does scream out as a problem to be solved by a new technology or strategy and not by a new and expensive hulking rocket.  Griffin does seem to assume that technology for various things including propellant storage will remain static.  Without money they may remain static anyway, but if there's no money then it's a moot point IMO.

It's one thing to assume that the technology over say a 5 year period will remain relatively static.  But by the time you get to 10, 15, and 20 years out, it becomes a lot more unrealistic.  Especially when there are multiple NASA and industry groups working on this very problem.  As it is, Ares V and LSAM are required to have long loiters with minimal boiloff.  In order to meet those requirements, advances in the state of the art are already required.  But taking it from there to ultra-low-boiloff systems and/or Zero Boiloff Systems just means some continued investment.  The fact that there are several groups (many headed up by Glenn Research Center or by ULA or by both) attacking this problem from different angles gives me very high confidence that a workable solution will be found, and probably not too far in the future.

If cryogenic fluid management (ie handling, storage, and transfer) technologies were funded at a reasonable rate (say a couple tens of millions per year), a *lot* of those issues would be worked out in before Ares I even gets a chance to fly.

~Jon

Offline PhalanxTX

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RE: Griffin speech - EELV would not work for Constellation
« Reply #27 on: 01/23/2008 07:45 PM »
Quote
Tim S - 23/1/2008  2:39 PM

Well said Mr Griffin.

We're not talking about U-Haulers for cargo here. We're talking manned space flight.

EELV folks on here need to stick to what they know.

Wouldn't that be EELVs?  And what's with the confrontational attitude?  I thought we're all working towards the same goal.  Why do you seem dead set on antagonizing those that disagree with the ESAS approach?
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Offline Jim

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RE: Griffin speech - EELV would not work for Constellation
« Reply #28 on: 01/23/2008 07:56 PM »
Quote
Tim S - 23/1/2008  3:39 PM

Well said Mr Griffin.

We're not talking about U-Haulers for cargo here. We're talking manned space flight.

EELV folks on here need to stick to what they know.

They know how to manrate vehicles, they know how to launch rockets

But  apparently MSFC doesn't know how to do either

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RE: Griffin speech - EELV would not work for Constellation
« Reply #29 on: 01/23/2008 07:57 PM »
Quote
Tim S - 23/1/2008  12:39 PM

Well said Mr Griffin.

We're not talking about U-Haulers for cargo here. We're talking manned space flight.

EELV folks on here need to stick to what they know.

Are you suggesting that the EELV guys stick to building rockets and leave the powerpoint wrangling to NASA?  Admittedly that's the happy state of affairs that has existed for the past twenty years, but at some point the Shuttle is going to go away and we'll need a replacement.
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RE: Griffin speech - EELV would not work for Constellation
« Reply #30 on: 01/23/2008 08:21 PM »
Quote
Chris Bergin - 23/1/2008  11:30 AM

http://www.nasa.gov/pdf/208916main_Space_Transportation_Association_22_Jan_08.pdf

Here's the part that will make many a coffee be spat over screens in Denver etc. ;)

snip

The Ares I lift requirement is 20.3 mT for the ISS mission and 23.3 mT for the lunar mission.  EELV lift capacity for both the Delta IV and Atlas V are insufficient, so a new RL-10 powered upper stage would be required, similar to the J-2X based upper stage for Ares I.  We considered using additional strap-on solid rocket boosters to increase EELV performance, but such clustering lowers overall reliability.

ship


What is the lift capability of Delta and Atlas heavy?  I am certain Atlas Heavy can lift this much and it is already at CDR with a very low risk to first flight.

Danny Deger
Danny Deger

Offline edkyle99

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RE: Griffin speech - EELV would not work for Constellation
« Reply #31 on: 01/23/2008 08:32 PM »
Quote
Norm Hartnett - 23/1/2008  1:57 PM

Not the Moon and not Mars but beyond, in other words a system that has the versatility to go to any place in space that is reasonable within the framework of the next thirty years.

Mars explains why Griffin's NASA is planning for Ares V.  It doesn't make sense for LEO.  It doesn't look like the most sensible way to do a lunar mission either.  But for Mars, since NASA would need the biggest launch vehicle available, the reasoning for Ares V begins to come into focus.  

Griffin says:  "I have written that a careful analysis of what we can do at NASA on constant-dollar budgets leads me to believe that we can realistically be on Mars by the mid-2030’s.  ...  We’ll be on Mars in thirty years, and when we go, we’ll be using hardware that we’re building today.  So we need to keep Mars in mind as we work, even now."

Quote
As to the Constellation architecture looking better cost-wise than any alternative for Mars IMO Ross has already addressed this in the DIRECT discussion. And to address your question, if it is not used for Mars there are still the NEOs, Mars' moons, and Venus.

A bigger launch vehicle is always going to cost less on a $/kg payload basis when it is compared to a smaller launch vehicle if the payload requirements are large enough or the program time frame is long enough, or both.  Ares V outhauls Direct, and so will always beat it at that cost-comparison game when it comes to Mars missions that start in 2030, require a million pounds of payload in LEO for each mission, and are part of a Mars exploration program that continues forever.

 - Ed Kyle

Offline edkyle99

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RE: Griffin speech - EELV would not work for Constellation
« Reply #32 on: 01/23/2008 08:38 PM »
Quote
Danny Dot - 23/1/2008  3:21 PM

Quote
Chris Bergin - 23/1/2008  11:30 AM

http://www.nasa.gov/pdf/208916main_Space_Transportation_Association_22_Jan_08.pdf

Here's the part that will make many a coffee be spat over screens in Denver etc. ;)

snip

The Ares I lift requirement is 20.3 mT for the ISS mission and 23.3 mT for the lunar mission.  EELV lift capacity for both the Delta IV and Atlas V are insufficient, so a new RL-10 powered upper stage would be required, similar to the J-2X based upper stage for Ares I.  We considered using additional strap-on solid rocket boosters to increase EELV performance, but such clustering lowers overall reliability.

ship


What is the lift capability of Delta and Atlas heavy?  I am certain Atlas Heavy can lift this much and it is already at CDR with a very low risk to first flight.

Danny Deger

My recollection is that NASA's study showed that the EELVs couldn't lift the payload when restricted to the low-loft ascent profiles.  They would also carry a lot of LAS mass, etc., that would limit them compared to a typical satellite in a shroud type payload.  Together, these factors dramatically cut the EELV mass delivery capabilities for a CEV.  

 - Ed Kyle

Offline Thomas

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Re: Griffin speech - EELV would not work for Constellation
« Reply #33 on: 01/23/2008 08:38 PM »
Why do people seem so surprise that the ARES (hello!!!!!!) series of vehicles have Mars as an ultimate destination? ;)

Offline edkyle99

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Re: Griffin speech - EELV would not work for Constellation
« Reply #34 on: 01/23/2008 08:43 PM »
Quote
Thomas - 23/1/2008  3:38 PM

Why do people seem so surprise that the ARES (hello!!!!!!) series of vehicles have Mars as an ultimate destination? ;)

Then why is NASA betting its foreseeable future on lunar exploration?

 - Ed Kyle

Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #35 on: 01/23/2008 08:47 PM »
Quote
edkyle99 - 23/1/2008  4:43 PM

Quote
Thomas - 23/1/2008  3:38 PM

Why do people seem so surprise that the ARES (hello!!!!!!) series of vehicles have Mars as an ultimate destination? ;)

Then why is NASA betting its foreseeable future on lunar exploration?

 - Ed Kyle
Basically because right now the moon is reachable, while Mars is not (yet).
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Online Herb Schaltegger

Come on, Ed - while I'm certainly not an Ares fan, let's be honest about that: they're betting the foreseeable future on lunar goals because #1) Congress has told them to, and #2) there's simply no money to go to Mars yet (if there ever will be).  This whole plan and subsequent architecture fight is politics and while Griffin has much to be held accountable for, so too does the administration and Congress for the current technical mess.
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Offline jongoff

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RE: Griffin speech - EELV would not work for Constellation
« Reply #37 on: 01/23/2008 08:50 PM »
Ed,
Quote
A bigger launch vehicle is always going to cost less on a $/kg payload basis when it is compared to a smaller launch vehicle if the payload requirements are large enough or the program time frame is long enough, or both.  Ares V outhauls Direct, and so will always beat it at that cost-comparison game when it comes to Mars missions that start in 2030, require a million pounds of payload in LEO for each mission, and are part of a Mars exploration program that continues forever.

Well....I would quibble with the "a bigger launch vehicle is always going to cost less on a $/kg basis" comment.  It depends a lot on assumptions.  Even after factoring the higher overhead of dealing with more launches, it may very well be that an RLV flying 50x per year at 10000lb LH2 per flight is going to cost a whole lot less per kg than an HLV that does it in only three flights.

For existing, very low launch rate vehicles (EELV, SDVs, etc), you might have a point, but I'd be careful with generalities like that.

~Jon

Offline libs0n

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RE: Griffin speech - EELV would not work for Constellation
« Reply #38 on: 01/23/2008 08:58 PM »
Quote
edkyle99 - 23/1/2008  4:38 PM

Quote
Danny Dot - 23/1/2008  3:21 PM

Quote
Chris Bergin - 23/1/2008  11:30 AM

http://www.nasa.gov/pdf/208916main_Space_Transportation_Association_22_Jan_08.pdf

Here's the part that will make many a coffee be spat over screens in Denver etc. ;)

snip

The Ares I lift requirement is 20.3 mT for the ISS mission and 23.3 mT for the lunar mission.  EELV lift capacity for both the Delta IV and Atlas V are insufficient, so a new RL-10 powered upper stage would be required, similar to the J-2X based upper stage for Ares I.  We considered using additional strap-on solid rocket boosters to increase EELV performance, but such clustering lowers overall reliability.

ship


What is the lift capability of Delta and Atlas heavy?  I am certain Atlas Heavy can lift this much and it is already at CDR with a very low risk to first flight.

Danny Deger

My recollection is that NASA's study showed that the EELVs couldn't lift the payload when restricted to the low-loft ascent profiles.  They would also carry a lot of LAS mass, etc., that would limit them compared to a typical satellite in a shroud type payload.  Together, these factors dramatically cut the EELV mass delivery capabilities for a CEV.  

 - Ed Kyle

One thing I don't think is being considered is that we're not talking about the Delta 4 Heavy of today, but a post-2012 one with its engines upgraded, which will supposedly boost its payload to LEO to 27,000kg.  That, I think, changes the parameters of discussion significantly when we start talking performance hits from safer ascent profiles and launch abort systems.

Offline savuporo

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RE: Griffin speech - EELV would not work for Constellation
« Reply #39 on: 01/23/2008 09:17 PM »
Quote
jongoff - 23/1/2008  11:50 AM
For existing, very low launch rate vehicles (EELV, SDVs, etc), you might have a point, but I'd be careful with generalities like that.
Considering Dnepr vs EELV launch costs per pound, the point just does not work.
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Offline vt_hokie

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RE: Griffin speech - EELV would not work for Constellation
« Reply #40 on: 01/23/2008 11:51 PM »
Quote
Norm Hartnett - 23/1/2008  2:57 PM

And to address your question, if it is not used for Mars there are still the NEOs, Mars' moons, and Venus.

Venus?!  Might be a little warm for the crew...  ;)

One non-technical reason I don't like the Ares I/Ares V approach is that it allows Congress to cancel the heavy lift portion that's needed for beyond-ISS missions while still preserving some basic spaceflight capability.  When was the last time NASA completed a program in its entirety with all planned enhancements?  Just take a look at ISS!  I think getting heavy lift launch vehicle capability up front is the only way to ensure it doesn't get cut when the inevitable delays and cost overruns occur.

Offline jongoff

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RE: Griffin speech - EELV would not work for Constellation
« Reply #41 on: 01/24/2008 12:17 AM »
Vt_Hokie,
Quote
Venus?!  Might be a little warm for the crew...  ;)

At the cloud top level, it really isn't that bad.  We're talking ~1atm pressure, roughly tropical temperatures, and since the atmosphere is mostly CO2, breathable air is a buoyant gas at that altitude.  I've heard people seriously propose building cloud colonies on venus.  Basically you use the breathable air at 1atm as the lifting gas, and build the whole colony as an airtight vessel.  Since the pressure is identical on both sides of the wall, even if there was a leak, it would be *very* slow.  You have to make sure your exterior surface can handle sulfuric acid (which are in the clouds), but that's also doable.  All in all it's interesting, because it may be one of the easiest planetary environments to build for.  No vacuum or ultra-low pressure to deal with, moderate temperatures, ~0.8g, plenty of atmosphere outside for thermal control purposes, plenty of sunlight (even below the cloudtop level, the light level is comparable to earth)....and you're surrounded by Carbon, Oxygen, Hydrogen, Nitrogen, and Sulfur.

Alas, the only problem is I can't think of too many markets to justify such a cloud city (other than tourism and/or retirement villas....)

Quote
One non-technical reason I don't like the Ares I/Ares V approach is that it allows Congress to cancel the heavy lift portion that's needed for beyond-ISS missions while still preserving some basic spaceflight capability.  When was the last time NASA completed a program in its entirety with all planned enhancements?  Just take a look at ISS!  I think getting heavy lift launch vehicle capability up front is the only way to ensure it doesn't get cut when the inevitable delays and cost overruns occur.

The other way to guarantee that you have exo-LEO capabilities that aren't at the mercy of Congress is to create a transportation architecture based on commercial elements and propellant depots.  But I'm sure I'm starting to sound like Jonny-One-Note on that count.  Once you have a propellant depot up and running long enough to start getting commercial customers, Congress (and NASA) is no longer on the critical path to the outward exploration/exploitation/development of space....

To me, *that's* sustainable.

~Jon

Offline edkyle99

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RE: Griffin speech - EELV would not work for Constellation
« Reply #42 on: 01/24/2008 12:31 AM »
Quote
savuporo - 23/1/2008  4:17 PM

Quote
jongoff - 23/1/2008  11:50 AM
For existing, very low launch rate vehicles (EELV, SDVs, etc), you might have a point, but I'd be careful with generalities like that.
Considering Dnepr vs EELV launch costs per pound, the point just does not work.

Oh, please.  Do I have to write out the obvious disclaimer every time?  The one that says "all other things being equal"?  As in comparing launch vehicles built in the same country, using the same currency, the same labor laws, the same safety rules, the same environmental regulations, etc.?  

NASA isn't going to use Russian-built launch vehicles to fly to Mars, or the Moon, or where ever, unless national policy changes.  If that happens, then we can sit down and compare Dnepr per pound versus Proton per pound, etc..

 - Ed Kyle


Offline landofgrey

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Re: Griffin speech - EELV would not work for Constellation
« Reply #43 on: 01/24/2008 12:59 AM »
Quote
Antares - 23/1/2008  1:46 PM

It's kinda funny that 2.5 years after ESAS, he's still having to sell the architecture.  By now, one would think it could stand on its own merits.

The speech was for the benefit of understanding for those who have questions, and I'm sure it was the last thing Griffin wanted to talk about... yet... again. Simply put, ESAS has already been sold to everyone who matters: Congress, industry and the majority of the public who care, which is why it is now essentially a matter of law. The opposition from a vocal minority of the public, scientists and engineers notwithstanding, the architecture has been "sold" and most people agree with the basic direction. I know that doesn't sit well with proponents of EELV-derived solutions or DIRECT, but some people also still don't accept that Ron Paul isn't going to get elected or realize they're in the 5% minority (backhanded analogy). Presonally, I just hope we don't get bit by the decisions that have been made.
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Quote
landofgrey - 24/1/2008  1:59 AM

Quote
Antares - 23/1/2008  1:46 PM

It's kinda funny that 2.5 years after ESAS, he's still having to sell the architecture.  By now, one would think it could stand on its own merits.

The speech was for the benefit of understanding for those who have questions, and I'm sure it was the last thing Griffin wanted to talk about... yet... again. Simply put, ESAS has already been sold to everyone who matters: Congress, industry and the majority of the public who care, which is why it is now essentially a matter of law. The opposition from a vocal minority of the public, scientists and engineers notwithstanding, the architecture has been "sold" and most people agree with the basic direction. I know that doesn't sit well with proponents of EELV-derived solutions or DIRECT, but some people also still don't accept that Ron Paul isn't going to get elected or realize they're in the 5% minority (backhanded analogy). Presonally, I just hope we don't get bit by the decisions that have been made.

Got to admit that's a great post.

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Re: Griffin speech - EELV would not work for Constellation
« Reply #45 on: 01/24/2008 01:11 AM »
Quote
landofgrey - 23/1/2008  8:59 PM
Simply put, ESAS has already been sold to everyone who matters: Congress, industry and the majority of the public who care, which is why it is now essentially a matter of law.

There is no law that says NASA must follow ESAS.   VSE is law

Offline yinzer

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Re: Griffin speech - EELV would not work for Constellation
« Reply #46 on: 01/24/2008 01:52 AM »
Furthermore, the first few years of the ESAS are already sold to everyone who matters.  There are two more administrations and four more Congresses that will have to stay sold on the ESAS to get to the first manned Orion flight.  These are the people to whom the serious discussions about the real problems of ESAS are addressed.
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Offline CFE

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RE: Griffin speech - EELV would not work for Constellation
« Reply #47 on: 01/24/2008 02:11 AM »
Quote
edkyle99 - 23/1/2008  2:38 PM

Quote
Danny Dot - 23/1/2008  3:21 PM

Quote
Chris Bergin - 23/1/2008  11:30 AM

http://www.nasa.gov/pdf/208916main_Space_Transportation_Association_22_Jan_08.pdf

Here's the part that will make many a coffee be spat over screens in Denver etc. ;)

snip

The Ares I lift requirement is 20.3 mT for the ISS mission and 23.3 mT for the lunar mission.  EELV lift capacity for both the Delta IV and Atlas V are insufficient, so a new RL-10 powered upper stage would be required, similar to the J-2X based upper stage for Ares I.  We considered using additional strap-on solid rocket boosters to increase EELV performance, but such clustering lowers overall reliability.

ship


What is the lift capability of Delta and Atlas heavy?  I am certain Atlas Heavy can lift this much and it is already at CDR with a very low risk to first flight.

Danny Deger

My recollection is that NASA's study showed that the EELVs couldn't lift the payload when restricted to the low-loft ascent profiles.  They would also carry a lot of LAS mass, etc., that would limit them compared to a typical satellite in a shroud type payload.  Together, these factors dramatically cut the EELV mass delivery capabilities for a CEV.  

 - Ed Kyle

Of course, the question must be asked why Orion weighs so much to begin with.  In my reading of the ESAS report, I have yet to find any rationale why the capsule is so huge for such a minuscule crew.  It begs the question of whether the capsule was deliberately designed to place it out of reach of the existing Delta family.

Delta IV Heavy is up to the task of launching a manned capsule, but it admittedly isn't the safest theoretical design out there.  On paper, Ares I is a much simpler, safer design.  But Delta IV Heavy has the edge in terms of actual flight experience.  Ares I has absolutely zero flight experience, and whatever heritage components are being used on Ares are being used in a flight environment that has little relevance to the one in which they were qualified (Shuttle & Saturn.)

So when Michael Griffin and co. boast about how safe Ares will be, tell them that you'll believe it when you see it.  An ounce of test is worth at least a pound of theory.
"Black Zones" never stopped NASA from flying the shuttle.

Offline jongoff

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RE: Griffin speech - EELV would not work for Constellation
« Reply #48 on: 01/24/2008 02:53 AM »
Ed,
Quote
Oh, please.  Do I have to write out the obvious disclaimer every time?  The one that says "all other things being equal"?  As in comparing launch vehicles built in the same country, using the same currency, the same labor laws, the same safety rules, the same environmental regulations, etc.?  

NASA isn't going to use Russian-built launch vehicles to fly to Mars, or the Moon, or where ever, unless national policy changes.  If that happens, then we can sit down and compare Dnepr per pound versus Proton per pound, etc..

I agree that Dnepr is an unfair comparison.  That said, even with launchers built in the same country, using the same labor and safety rules, and the same environmental regulations, there still is plenty of other things which sometimes aren't equal.  The biggest one being the effect of flight rate.  It's possible that even though Jupiter is slightly smaller than Ares-V, that it may end up being cheaper in $/kg because it could fly more often, uses less engines, less segments, requires less R&D to be amortized, etc.

~Jon

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RE: Griffin speech - EELV would not work for Constellation
« Reply #49 on: 01/24/2008 04:45 AM »
Quote
Tim S - 23/1/2008  2:39 PM
Well said Mr Griffin.

We're not talking about U-Haulers for cargo here. We're talking manned space flight.

EELV folks on here need to stick to what they know.
I hope you get up early and have Sen. Shelby on speed dial.  Some morning in the not too distant future when the sun rises over the Atlantic, the dawn will be cast on a winged vehicle atop an EELV pointed at Space.  Wisps of GOX will be venting from its haunches (no vent arm needed).  Ice will be forming and falling away in the humid air.  Turbopumps will spin and steam and maybe carbon dioxide will rush forth, without a hint of HCl or molten aluminum polluting the precious refuge.

An hour or so later, there will be much rejoicing in Denver, Florida, LA AFB, and the south side of the Tennessee River in Northern Alabama.  Those on the north side of the river will still be wondering why their square-tired Ferrari is still 5 years from launch and there's a Ford in space.  That night, all those Congressmen who don't usually care about Space will look skyward and have their own Sputnik moment as the "cargo" orbits past and realize there's a chance America may still be able to sell burgers on the moon before we have to put up with free samples of bourbon chicken.

We'll stick with what we know: fulfilling customer requirements, market-driven systems, true risk management, successful product development, cost-effective mission success.

Please, go do Ares V.  Just stop wasting time and money on another 50K-class launch vehicle when cheaper, adequate ones already exist.
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline khallow

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Re: Griffin speech - EELV would not work for Constellation
« Reply #50 on: 01/24/2008 05:09 AM »
Quote
landofgrey - 23/1/2008  5:59 PM

Quote
Antares - 23/1/2008  1:46 PM

It's kinda funny that 2.5 years after ESAS, he's still having to sell the architecture.  By now, one would think it could stand on its own merits.

The speech was for the benefit of understanding for those who have questions, and I'm sure it was the last thing Griffin wanted to talk about... yet... again. Simply put, ESAS has already been sold to everyone who matters: Congress, industry and the majority of the public who care, which is why it is now essentially a matter of law. The opposition from a vocal minority of the public, scientists and engineers notwithstanding, the architecture has been "sold" and most people agree with the basic direction. I know that doesn't sit well with proponents of EELV-derived solutions or DIRECT, but some people also still don't accept that Ron Paul isn't going to get elected or realize they're in the 5% minority (backhanded analogy). Presonally, I just hope we don't get bit by the decisions that have been made.

Another thing to keep in mind is that even if the architecture were absolutely perfect, it'd still be threatened by the "this money could be better spent elsewhere" crowd. Having said that, I don't think the Ares program is assured of survival. Not even Ares 1. This year will be a critical one for Ares.
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Offline kkattula2

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RE: Griffin speech - EELV would not work for Constellation
« Reply #51 on: 01/24/2008 06:12 AM »
Quote
A bigger launch vehicle is always going to cost less on a $/kg payload basis when it is compared to a smaller launch vehicle if the payload requirements are large enough or the program time frame is long enough, or both.  Ares V outhauls Direct, and so will always beat it at that cost-comparison game when it comes to Mars missions that start in 2030, require a million pounds of payload in LEO for each mission, and are part of a Mars exploration program that continues forever.

That might be true over 30 years, IF you only compare Ares V and Jupiter 232.

But if you throw in Ares I and Jupiter 120 for the LEO missions. Direct is a little ahead.

Then if you add in other jobs Juptiter 120 can do (ISS construction, large science payloads, etc), Direct is well ahead.

Then if you factor in the costs of; a big post shuttle gap, reduced safety margins in the CEV, workforce retention, impact on current budget, Direct is miles ahead.


Griffin is missing the big picture, even though he practically defines it. Nasa needs cheap, reliable, crew and heavy launch capability. Get that working, using your existing technology base, and then you can spend money on the more interesting things. Like exploration.

Offline renclod

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Re: Griffin speech - EELV would not work for Constellation
« Reply #52 on: 01/24/2008 06:35 AM »
Quote
kevin-rf - 23/1/2008  9:42 PM

Noticed he said nothing about the five segment thrust oscillation issues

But he did. In the Q&A session that follows the speach.

The speach has a few twists on top of what you can read in the pdf.

Keith Cowing has recorded the whole session and has made it available for all to listen - thanks Keith !
See
http://www.spaceref.com/news/viewsr.html?pid=26756
http://onorbit.com/podcasts/2008.01.08.griffin.sta.m4a
feed://onorbit.com/podcasts/onorbitpodcasts.xml

 Enjoy !

Offline savuporo

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Re: Griffin speech - EELV would not work for Constellation
« Reply #53 on: 01/24/2008 07:03 AM »
Quote
Chris Bergin - 23/1/2008  4:01 PM

Quote
landofgrey - 24/1/2008  1:59 AM

Quote
Antares - 23/1/2008  1:46 PM

It's kinda funny that 2.5 years after ESAS, he's still having to sell the architecture.  By now, one would think it could stand on its own merits.

The speech was for the benefit of understanding for those who have questions, and I'm sure it was the last thing Griffin wanted to talk about... yet... again. Simply put, ESAS has already been sold to everyone who matters: Congress, industry and the majority of the public who care, which is why it is now essentially a matter of law. The opposition from a vocal minority of the public, scientists and engineers notwithstanding, the architecture has been "sold" and most people agree with the basic direction. I know that doesn't sit well with proponents of EELV-derived solutions or DIRECT, but some people also still don't accept that Ron Paul isn't going to get elected or realize they're in the 5% minority (backhanded analogy). Presonally, I just hope we don't get bit by the decisions that have been made.

Got to admit that's a great post.

Except that it tries to paint a picture that really isnt there. Being "sold" doesnt mean eternal support from political institutions, and saying things like "vocal minority of engineers" and "most people agree" is just pulling stuff from thin air.
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Offline savuporo

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RE: Griffin speech - EELV would not work for Constellation
« Reply #54 on: 01/24/2008 07:17 AM »
Quote
CFE - 23/1/2008  5:11 PM
Of course, the question must be asked why Orion weighs so much to begin with.  In my reading of the ESAS report, I have yet to find any rationale why the capsule is so huge for such a minuscule crew.  
If you read Griffins speech, you'll notice that even the crew size is a random number pulled out of .. air. The only justification is "its bigger than Apollo", which is a very weak argument to commit to billions worth of suspect hardware, without doing further tradeoff analysis.
What if it was three ? What if you landed two landers in close coordination, both carrying a crew of two, i.e. use lunar surface mission staging ?
Another big gotcha is the entire justification on going heavy lift: hydrogen boiloff, and "obviousness" of not wanting to stage 20-ton modules on LEO. I never understood how it became so obvious.
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Offline Jim

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RE: Griffin speech - EELV would not work for Constellation
« Reply #55 on: 01/24/2008 11:59 AM »
Quote
Antares - 24/1/2008  12:45 AM

Quote
Tim S - 23/1/2008  2:39 PM
Well said Mr Griffin.

We're not talking about U-Haulers for cargo here. We're talking manned space flight.

EELV folks on here need to stick to what they know.
I hope you get up early and have Sen. Shelby on speed dial.  Some morning in the not too distant future when the sun rises over the Atlantic, the dawn will be cast on a winged vehicle atop an EELV pointed at Space.  Wisps of GOX will be venting from its haunches (no vent arm needed).  Ice will be forming and falling away in the humid air.  Turbopumps will spin and steam and maybe carbon dioxide will rush forth, without a hint of HCl or molten aluminum polluting the precious refuge.

An hour or so later, there will be much rejoicing in Denver, Florida, LA AFB, and the south side of the Tennessee River in Northern Alabama.  Those on the north side of the river will still be wondering why their square-tired Ferrari is still 5 years from launch and there's a Ford in space.  That night, all those Congressmen who don't usually care about Space will look skyward and have their own Sputnik moment as the "cargo" orbits past and realize there's a chance America may still be able to sell burgers on the moon before we have to put up with free samples of bourbon chicken.

We'll stick with what we know: fulfilling customer requirements, market-driven systems, true risk management, successful product development, cost-effective mission success.

Please, go do Ares V.  Just stop wasting time and money on another 50K-class launch vehicle when cheaper, adequate ones already exist.

And there is even irony.  MSFC couldn't handle the project and got it canceled.

Offline meiza

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Re: Griffin speech - EELV would not work for Constellation
« Reply #56 on: 01/24/2008 12:23 PM »
I think four crew is justified by enabling two EVA pairs. If you have three, it's dangerous if one goes alone and thus you have to move as a group of three and then it's not that much more useful than just two since you can't spread out much. So either 2 or 4.

I do realize that this is just a speech with limited time and Griffin can't just include every possible reasoning but some stuff still would warrant closer scrutiny.

I'm especially interested in the Delta IV heavy aborts and payload capability loss with a depressed trajectory. And the same thing for Atlas V heavy (18 months from Go to production).

Offline kevin-rf

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Re: Griffin speech - EELV would not work for Constellation
« Reply #57 on: 01/24/2008 01:18 PM »
Quote
meiza - 24/1/2008  8:23 AM

I think four crew is justified by enabling two EVA pairs. If you have three, it's dangerous if one goes alone and thus you have to move as a group of three and then it's not that much more useful than just two since you can't spread out much. So either 2 or 4.

A few points on that magic number.

First, on the moon and even in space you are limited to the crew on hand. There is no going for help. It doesn't matter if it is two, three, or four. You are limited to the muscle power of the others in the group. There are no solo space walks, most likely for that reason.

A few things to think about, (I do a fair amount of project caving and actually have a good amount of cave rescue training.)

In caving where you are realistically cut off from the rest of the world in a hostile enviroment the magic number is three. One to stay with the patient (we never use the word vicitim, to cavers thats means passed on to the underworld) and one to go for help. The first rule is to self rescue if you can, sending one ahead, and one to assist. Think about it, if you are eight hours from the surface, it will take at least 24 for assistance to arrive. That is why self rescue is so important. On the moon it can be measured in weeks or even months. Show me a moon suit that has a months air supply. It is also worth noting that multiple people injured during a cave accident is rare. It will most likely be the same during a lunar sortie.

The other thing to think about is cave diving. I have several friends that do it and do drag tanks when asked. In cave diving the magic number is almost always two (unless your a NE sump diver, then it is one (the thought of death wish comes to mind) ). It is an unforgiving enviroment, you almost never hear about non fatal cave diving accidents. When you reach a third of a tank consumed turn arround, keep an eye on the guy behind you, if you loose track of them stop and wait for them, assist them if they need help. This is very similar to space walks on the ISS, ever notice they are done in groups of two, even when the shuttle is docked.

During a surface sortie, the more the better to help out with any issue that might develop. Four is not the magic number, just a nice number since you now have three people to drag back an injured team mate. ( One to grab each arm, and another to take a video to post on YouTube ;) )
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Offline James Lowe1

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RE: Griffin speech - EELV would not work for Constellation
« Reply #58 on: 01/24/2008 03:58 PM »
Thread deleted back to before the arguments. Uh oh, too far back it seems :(


Offline clongton

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RE: Griffin speech - EELV would not work for Constellation
« Reply #59 on: 01/24/2008 04:16 PM »
Quote
James Lowe1 - 24/1/2008  11:58 AM

Thread deleted back to before the arguments. Uh oh, too far back it seems :(

Thank you very much.
This speech is a major event, and there is room here for an awful lot of evaluation and discussion of it. It’s unfortunate when it drops into such back and forth. New posters need to learn the proper use of PM’s for that stuff if they wish to pursue it and to keep it off the thread.
Thanks
P.S. I'm sure you'll fix it.  :)
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I started my career on the Saturn-V F-1A engine

Offline kevin-rf

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RE: Griffin speech - EELV would not work for Constellation
« Reply #60 on: 01/24/2008 04:52 PM »
Quote
James Lowe1 - 24/1/2008  11:58 AM

Thread deleted back to before the arguments. Uh oh, too far back it seems :(


Wait, you censor'd Chris? Wow that takes some somtin or other ;)
If you're happy and you know it,
It's your med's!

Offline James Lowe1

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RE: Griffin speech - EELV would not work for Constellation
« Reply #61 on: 01/24/2008 05:03 PM »
Quote
kevin-rf - 23/1/2008  12:52 PM

Quote
James Lowe1 - 24/1/2008  11:58 AM

Thread deleted back to before the arguments. Uh oh, too far back it seems :(


Wait, you censor'd Chris? Wow that takes some somtin or other ;)

I'm staying in after class  :o

Offline Danny Dot

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RE: Griffin speech - EELV would not work for Constellation
« Reply #62 on: 01/24/2008 06:59 PM »
Quote
edkyle99 - 23/1/2008  3:38 PM

snip

My recollection is that NASA's study showed that the EELVs couldn't lift the payload when restricted to the low-loft ascent profiles.  They would also carry a lot of LAS mass, etc., that would limit them compared to a typical satellite in a shroud type payload.  Together, these factors dramatically cut the EELV mass delivery capabilities for a CEV.  

 - Ed Kyle

My recollection is the EELVs loose about 5% to fly the lower trajectories -- I got this number from a ULA engineer.  Maybe less if you assume a controlled entry as opposed to a ballistic entry -- and I don't think NASA is requiring a ballistic entry anymore.  Can someone point us to some actual data on this?  The Navy proved in about 1963 astronauts can easily fly a 20 G entry profile.

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Offline meiza

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Re: Griffin speech - EELV would not work for Constellation
« Reply #63 on: 01/24/2008 07:31 PM »
5% is 1.25 t from 25 t. So 23.75 t. I wonder with the new RS-68...
And Atlas V heavy had more performance margin, I think it was 28 t to 28 degrees...

Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #64 on: 01/24/2008 10:31 PM »
Someone said a while back that the VSE provided a direction to go in but did not specify "heavy lift" to be utilized. Here is the appropriate portion of the 2005 Authorization Act that set the VSE in motion and made it law:

"The Administrator shall, to the fullest extent possible consistent with a
successful development program, use the personnel, capabilities, assets, and
infrastructure of the Space Shuttle program in developing the Crew Exploration
Vehicle, Crew Launch Vehicle, and a heavy-lift launch vehicle." (emphasis mine).

NASA is required by law to build a heavy lift launch vehicle to use in execution of the VSE.
Notice that it required the "use the personnel, capabilities, assets, and
infrastructure of the Space Shuttle program" to build it. A Shuttle-Derived launch vehicle was mandated by this authorization act.

I'm not bringing this up to justify STS vs EELV; only to point out what NASA was directed by Congress to do. This comes directly from Dr Griffin's speech.
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I started my career on the Saturn-V F-1A engine

Offline TrueGrit

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Re: Griffin speech - EELV would not work for Constellation
« Reply #65 on: 01/24/2008 10:50 PM »
The administrator can go build his stick...  ULA has moved on.  ULA will continue to fly the most capable vehicles in the world, and make its customers happy.  While NASA spends billions relearning everything they forgot in the last 30 yrs ULA will get real flight success.

And as far as not being able to meet the administrator’s requirements...  ULA will begin flying the upgraded Delta IV, with 27 mT ISS capability, at least 2 years before the first 5-segment booster is ever flown.  And 4 before a fully capable Ares is ready to put people on board.  And for note the Delta IV upgrade will exceed the administrator’s own 23.3 mT need by 1 mT (assuming 10% loss due to the lower manned trajectory).  All without a penny of NASA money...  And without the need of a higher thrust upperstage engine despite the administrator's claims.

And finally...  By the time the administrators successor gets around to begging from congressional money for the heavy booster ULA will have moved on to RL-60 and ACES.  They'll also conveniently forget this speech when the same successor comes asking for support because NASA is stuck in LEO again.

Offline CFE

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Re: Griffin speech - EELV would not work for Constellation
« Reply #66 on: 01/25/2008 12:30 AM »
Quote
TrueGrit - 24/1/2008  4:50 PM

And finally...  By the time the administrators successor gets around to begging from congressional money for the heavy booster ULA will have moved on to RL-60 and ACES.  They'll also conveniently forget this speech when the same successor comes asking for support because NASA is stuck in LEO again.

Is RL-60 still an active program?  P&W hasn't mentioned it in press releases since 2003.

As far as congressional language mandating a "heavy lift launch vehicle" is concerned, all I have to say is that everybody's got a different definition of what "heavy lift" is.  After all, they don't call it a Delta IV Heavy for nothing.
"Black Zones" never stopped NASA from flying the shuttle.

Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #67 on: 01/25/2008 02:19 AM »
Quote
CFE - 24/1/2008  8:30 PM

Quote
TrueGrit - 24/1/2008  4:50 PM

And finally...  By the time the administrators successor gets around to begging from congressional money for the heavy booster ULA will have moved on to RL-60 and ACES.  They'll also conveniently forget this speech when the same successor comes asking for support because NASA is stuck in LEO again.

Is RL-60 still an active program?  P&W hasn't mentioned it in press releases since 2003.

As far as congressional language mandating a "heavy lift launch vehicle" is concerned, all I have to say is that everybody's got a different definition of what "heavy lift" is.  After all, they don't call it a Delta IV Heavy for nothing.
Well, since we are speaking of Dr Griffin's interpretation of the law (not yours or mine), it's appropriate to say that in several places he defined "heavy lift" as 100mT or more. I know that at least one of them was at a congressional hearing because we quoted it in the 2007 AIAA paper.

Oh, and btw, back in the day (when Saturn-V was alive and well), the terms we used all the time was "Light Lift" was 25 tons, "Medium Lift" was 50 tons and "Heavy Lift" was 100 tons. That's "probably" where Dr Griffin gets his definition, because he comes from that school of thought. fwiw
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Offline Lee Jay

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Re: Griffin speech - EELV would not work for Constellation
« Reply #68 on: 01/25/2008 02:48 AM »
Quote
clongton - 24/1/2008  4:31 PM
NASA is required by law to build a heavy lift launch vehicle to use in execution of the VSE.
Notice that it required the "use the personnel, capabilities, assets, and
infrastructure of the Space Shuttle program" to build it. A Shuttle-Derived launch vehicle was mandated by this authorization act.

Then why aren't they building one (or two)?

Offline savuporo

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Re: Griffin speech - EELV would not work for Constellation
« Reply #69 on: 01/25/2008 04:47 AM »
Quote
Lee Jay - 24/1/2008  5:48 PM

Quote
clongton - 24/1/2008  4:31 PM
NASA is required by law to build a heavy lift launch vehicle to use in execution of the VSE.
Notice that it required the "use the personnel, capabilities, assets, and
infrastructure of the Space Shuttle program" to build it. A Shuttle-Derived launch vehicle was mandated by this authorization act.

Then why aren't they building one (or two)?
Isnt NASA is successfully ignoring a bunch of other acts and laws, signed earlier ? Something about Space Settlement in 88, space commercialization acts and stuff like that ?
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Offline kraisee

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Re: Griffin speech - EELV would not work for Constellation
« Reply #70 on: 01/25/2008 06:47 AM »
Quote
meiza - 24/1/2008  3:31 PM

5% is 1.25 t from 25 t. So 23.75 t. I wonder with the new RS-68...
And Atlas V heavy had more performance margin, I think it was 28 t to 28 degrees...

The latest number *from ULA* is that the current D-IV-H is around 21.2mT to 28.5deg LEO with a crew - although I suspect this to a much better orbit than Ares-I's -11x100nm.

Ross.
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Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #71 on: 01/25/2008 11:18 AM »
Quote
savuporo - 25/1/2008  12:47 AM

Quote
Lee Jay - 24/1/2008  5:48 PM

Quote
clongton - 24/1/2008  4:31 PM
NASA is required by law to build a heavy lift launch vehicle to use in execution of the VSE.
Notice that it required the "use the personnel, capabilities, assets, and
infrastructure of the Space Shuttle program" to build it. A Shuttle-Derived launch vehicle was mandated by this authorization act.

Then why aren't they building one (or two)?
Isnt NASA is successfully ignoring a bunch of other acts and laws, signed earlier ? Something about Space Settlement in 88, space commercialization acts and stuff like that ?
They claim that they are. But anyone who knows anything is fully aware that is a load of poppycock. All of their claims are not intended for those of us who actually know better. They are intended for those in the public and in government who can make budgetary decisions but don't know enough about the subject to actually see the flaws in the logic or the half-truths in the statements.
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Offline Danny Dot

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Re: Griffin speech - EELV would not work for Constellation
« Reply #72 on: 01/25/2008 11:55 AM »
Quote
clongton - 25/1/2008  6:18 AM

Quote
savuporo - 25/1/2008  12:47 AM

snip

Isnt NASA is successfully ignoring a bunch of other acts and laws, signed earlier ? Something about Space Settlement in 88, space commercialization acts and stuff like that ?
They claim that they are. But anyone who knows anything is fully aware that is a load of poppycock. All of their claims are not intended for those of us who actually know better. They are intended for those in the public and in government who can make budgetary decisions but don't know enough about the subject to actually see the flaws in the logic or the half-truths in the statements.

This is the behavior I have seen from NASA since I joined them in 1990.  Once a decision is made, all discussion to support the other side of the story is "officially" banned.  Only discussion that supports the decision is allowed.  This is the culture that has engineers stay quiet while management makes a decision that is not safe.

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Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #73 on: 01/25/2008 01:46 PM »
Quote
jongoff - 23/1/2008  3:18 PM

While one could definitely draw the conclusion that Griffin drew, ie. that hydrogen boiloff issues imply it would be better to launch the system in fewer pieces, one could also draw a different conclusion.  The conclusion I would draw is that if cryogenic propellant storage technologies are so critical--develop them.  Don't let the existing state of the art in propellant handling drive transportation system decisions for projects that won't be undertaken for 15-20 years!

~ Jon
I just don’t see a propellant depot or long term storage as being that difficult to develop, I really don’t. Centaur has been successfully handling this for years with very low boiloff and the newest technology employed on ICES reduces boiloff, I believe, to very near zero. So I really don’t understand Dr Griffin’s rationale here; it displays either a lack of understanding of existing and proven technologies or a refusal to believe it. Either way it shows him to have an inadequate understanding of the subject.

And if one chooses to not believe what Centaur is actually doing right now as we speak, and has been doing for 40 years, then don’t even bother storing the cryogens. Think about this. What propellant stores extremely well, for very long periods of time, in its natural state, in space, with NO human intervention? We want LH2 and LOX, right? Then store it as water ice! Ship it to the Mars ship as liquid water on any kind of rocket that can get to it, pump it into the tank and let it freeze, perfect for the extremely cold space environment. Keep it behind a sun shield so it’ll stay frozen, by itself. When propellant is needed, subliminate some and crack it into H2 and O2 gasses, liquefy the gasses and send them to the propellant tanks. What’s so hard about that? Hell, I subliminate ice in my freezer all the time. It ends up on the freezer walls as frost because I don’t have my SEP cracking device set up yet. How’s that for long term storage of propellants?
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline mikeh

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Re: Griffin speech - EELV would not work for Constellation
« Reply #74 on: 01/25/2008 02:31 PM »
Quote
landofgrey - 23/1/2008  7:59 PM

Quote
Antares - 23/1/2008  1:46 PM

It's kinda funny that 2.5 years after ESAS, he's still having to sell the architecture.  By now, one would think it could stand on its own merits.

The speech was for the benefit of understanding for those who have questions, and I'm sure it was the last thing Griffin wanted to talk about... yet... again. Simply put, ESAS has already been sold to everyone who matters: Congress, industry and the majority of the public who care, which is why it is now essentially a matter of law. The opposition from a vocal minority of the public, scientists and engineers notwithstanding, the architecture has been "sold" and most people agree with the basic direction. I know that doesn't sit well with proponents of EELV-derived solutions or DIRECT, but some people also still don't accept that Ron Paul isn't going to get elected or realize they're in the 5% minority (backhanded analogy). Presonally, I just hope we don't get bit by the decisions that have been made.

Well "said".  Dr. Griffin is still trying to educate others about systems engineering.  Systems engineering is not just about the hardware and techniques.  Again, his speech shows that one must consider ALL factors including the political and funding constraints.  He knows that if we restrict our endeavours to LEO with this architecture then we'll be right back where we are now, no capability beyond LEO.  Just as the Apollo hardware and techniques were a series of compromises, so this development must be also.  Perfect? No but what ever the final product becomes (if it survives all the sniping and politics) it will do what it's designed for.
===========================================
"You can't BS physics".

Don Arabian-Head of MER during Apollo

Offline TrueGrit

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Re: Griffin speech - EELV would not work for Constellation
« Reply #75 on: 01/25/2008 03:02 PM »
Quote
Is RL-60 still an active program?  P&W hasn't mentioned it in press releases since 2003.

I'll accept that right now RL-60 is on hold, and RL-engine development is right now focused on CECE which has lunar applications.  But you're fogeting how far out NASA has placed Ares V development...  They don't get authorization to proceed on Ares V for 5 yrs.  And it will take another 3 to reach CDR, and 6 to start flying.  By then I'd say we'd see an interest in rekindling RL-60.  At a minimum we'll see ULA start work on the Advanced Cryogenic Evolved Stage (ACES) with ability to support upto 4 RL-10s.  And unlike J-2 RL-60 development is fairly new and could be rekindled quickly, and so is MB-60 which will play a role now that P&W and Rocketdyne are one.

Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #76 on: 01/25/2008 03:22 PM »
Quote
pad rat - 25/1/2008  11:15 AM

There is suffficient wiggle room built into that language that would allow NASA to deviate in any way it chooses.

"...to the fullest extent possible consistent with a
successful development program..."
Yes there is. But this thread is really about how Dr Griffin has wiggled to his interpretation. So long as he remains the administrator, his interpretation will reign supreme.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline david_zz_smith

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RE: Griffin speech - EELV would not work for Constellation
« Reply #77 on: 01/26/2008 02:11 PM »
I find the following statement from Griffin remarkable:

“We have shared the complete analysis with the DoD, various White House staff offices, CBO, GAO, and our Congressional oversight committees. Our analysis showed that for the combined crew and heavy-lift launch vehicles, the development cost of an EELV-derived architecture is almost 25% higher than that of the Shuttle-derived approach. The recurring cost of the heavy-lift Ares V is substantially less than competing approaches, and the recurring cost of an EELV upgraded to meet CEV requirements is, at best, comparable to that for Ares I. All independent cost analyses have been in agreement with these conclusions.”

The major independent study regarding VSE launch costs that I’m aware of was conducted by the CBO and published in 2005 at:
http://www.cbo.gov/ftpdocs/76xx/doc7635/10-09-SpaceLaunch.pdf

CBO’s results show total costs for development and operation in Table E2 page 51:

Alternative 1: Delta+ = $27.9B
Alternative 2: Atlas+ = $26.1B
Alternative 6: Ares I & V =  $32.4B

Offline david_zz_smith

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RE: Griffin speech - EELV would not work for Constellation
« Reply #78 on: 01/26/2008 02:23 PM »
Is Griffin talking about a nuclear thermal based Mars architecture?

“When we consider that maybe half the Mars mission mass in LEO is liquid hydrogen, and if we understand that the control of hydrogen boiloff in space is one of the key limiting technologies for deep space exploration, the need to conduct fewer rather than more launches to LEO for early Mars missions becomes glaringly apparent.”

With any LH2/LO2 architecture it is likely that propellant will constitute about 80% of the LEO mass, of this LH2 represents ~1/6, or about ~13% of the total LEO mass, LO2 makes up ~67%.  With most administrators and speeches one could chalk this up to an oversight.  But we are talking about Dr. Griffin here with a pre-written text.

Granted, LO2 is still a cryogen, and still requires careful consideration and design for storage.  But with a boiling point of 180 R, LO2 is much easier to store than LH2 boiling at 40 R.  One can easily envision launching the LO2, EDS, trans-Mars spacecraft before launching the LH2 and people, minimizing issues with timing.

Offline david_zz_smith

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RE: Griffin speech - EELV would not work for Constellation
« Reply #79 on: 01/26/2008 02:42 PM »
Has Griffin forgotten congresses direction to launch CEV as close as possible to 2010 to minimize a gap in US launch capability?
“The Administrator shall manage human space flight programs to strive to
achieve the following milestones,
(A) Returning Americans to the Moon no later than 2020.
(B) Launching the Crew Exploration Vehicle as close to 2010 as possible.
(C) Increasing knowledge of the impacts of long duration stays in space on the human body using the most appropriate facilities available, including the ISS.
(D) Enabling humans to land on and return from Mars and other destinations on a timetable that is technically and fiscally possible.”

It is hard to understand Griffin’s real motivations regarding not launching Orion on EELV’s for ISS mission, or praying for the minimal COTS investment to pan out for ISS cargo services, especially when the ISS is such a national asset.  

“But a plain reading of policy and law requires us to understand that, throughout four presidential administrations and twenty-plus Congressional votes authorizing tens of billions of dollars for its development, the ISS has remained an established feature of U.S. space policy. Its support and sustenance cannot be left to chance; the CEV must and will be capable of fulfilling this requirement, and the exploration architecture must and will take that into account. This is nothing more than common sense. The U.S. government will not abandon its commitment to the development and utilization of low Earth orbit (LEO).”

The net result of NASA’s ongoing direction is purchasing additional rides for US astronauts on Soyuz and additional cargo services from Progress, as demonstrated this past summer, and likely to be required again and again in the future to cover the 2010 through at least 2015 time period.  Since when has outsourcing billions of dollars worth of high technology US jobs, technical know how and capability become the role of NASA?

Offline clongton

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RE: Griffin speech - EELV would not work for Constellation
« Reply #80 on: 01/26/2008 03:14 PM »
David;
In my opinion, see my response to a similar question at
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=11586#M235173
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline meiza

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Re: Griffin speech - EELV would not work for Constellation
« Reply #81 on: 01/26/2008 04:31 PM »
David, he probably means nuclear thermal rockets (NTR) which run on hydrogen only. Their use is outlined in the Mars reference mission 3.0.

Offline Zach

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Re: Griffin speech - EELV would not work for Constellation
« Reply #82 on: 01/26/2008 05:18 PM »
Quote
meiza - 26/1/2008  11:31 AM

David, he probably means nuclear thermal rockets (NTR) which run on hydrogen only. Their use is outlined in the Mars reference mission 3.0.

NTR is certainly the likely interpretation of Griffin's comment.  But if Griffin believes that hydrogen boilof is a key limiting technology in an NTR world he has his priorities mixed up: "control of hydrogen boiloff in space is one of the key limiting technologies for deep space exploration".  Development of the reactor, human rating it, getting approval to launch said reactor, and operating it, especially in Earth orbit make hydrogen storage pale in comparison.

Offline sbt

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Re: Griffin speech - EELV would not work for Constellation
« Reply #83 on: 01/27/2008 11:23 AM »

Quote
Zach - 26/1/2008  6:18 PM  NTR is certainly the likely interpretation of Griffin's comment.  But if Griffin believes that hydrogen boilof is a key limiting technology in an NTR world he has his priorities mixed up: "control of hydrogen boiloff in space is one of the key limiting technologies for deep space exploration".  Development of the reactor, human rating it, getting approval to launch said reactor, and operating it, especially in Earth orbit make hydrogen storage pale in comparison.

Note that he said 'one of' not 'the'. All the enabling technologies have to be in place for something to be enabled. A reactor that lacks fuel because it has all boiled away is going to look pretty silly, as is a stock of LH with no way to make use of it.

The thing with control of boiloff is that it is 'dual use' - the technology benefits both Chemical and Nuclear Thermal propulsion.

Rick

I am not interested in your political point scoring, Ad Hominem attacks, personal obsessions and vendettas. - No matter how cute and clever you may think your comments are.

Offline Zach

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Re: Griffin speech - EELV would not work for Constellation
« Reply #84 on: 01/27/2008 01:04 PM »
Quote
sbt - 27/1/2008  6:23 AM

Quote
Zach - 26/1/2008  6:18 PM  NTR is certainly the likely interpretation of Griffin's comment.  But if Griffin believes that hydrogen boilof is a key limiting technology in an NTR world he has his priorities mixed up: "control of hydrogen boiloff in space is one of the key limiting technologies for deep space exploration".  Development of the reactor, human rating it, getting approval to launch said reactor, and operating it, especially in Earth orbit make hydrogen storage pale in comparison.

Note that he said 'one of' not 'the'. All the enabling technologies have to be in place for something to be enabled. A reactor that lacks fuel because it has all boiled away is going to look pretty silly, as is a stock of LH with no way to make use of it.

The thing with control of boiloff is that it is 'dual use' - the technology benefits both Chemical and Nuclear Thermal propulsion.

Rick


Fully agree with boiloff control being dual use.  But to use thermal mitigation measures as an excuse for developing Ares V, the "biggest rocket that we can afford", over J-232 or EELV class simply to reduce the duration of storing LH2 is silly:

"But if we split the EOR lunar architecture into two equal but smaller
vehicles, we will need ten or more launches to obtain the same Mars-bound
payload in LEO, and that is without assuming any loss of packaging efficiency for
the launch of smaller payloads. When we consider that maybe half the Mars
mission mass in LEO is liquid hydrogen, and if we understand that the control of
hydrogen boiloff in space is one of the key limiting technologies for deep space
exploration, the need to conduct fewer rather than more launches to LEO for early
Mars missions becomes glaringly apparent.

So if we want a lunar transportation architecture that looks back to the ISS
LEO logistics requirement, and forward to the first Mars missions, it becomes
apparent that the best approach is a dual-launch EOR mission, but with the total
payload split unequally. The smaller launch vehicle puts a crew in LEO every time
it flies, whether they are going to the ISS or to the Moon. The larger launch
vehicle puts the lunar (or, later, Mars) cargo in orbit. After rendezvous and
docking, they are off to their final destination."

I don't find anything glaringly apparent. An NTR will require LH2 be stored for the better part of 2 years during the trip to and stay at Mars to supply the LH2 propellant for the return trip.  If we don't know how to store LH2 in Earth orbit, where mass and errors aren't nearly as critical as during the Mars journey we need to use a different technology or not go to Mars.

Offline alexterrell

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RE: Griffin speech - EELV would not work for Constellation
« Reply #85 on: 03/29/2008 08:45 PM »
Quote
jongoff - 23/1/2008  2:18 PM

While one could definitely draw the conclusion that Griffin drew, ie. that hydrogen boiloff issues imply it would be better to launch the system in fewer pieces, one could also draw a different conclusion.  The conclusion I would draw is that if cryogenic propellant storage technologies are so critical--develop them.


Why develop them? There's a very good technology for storing hydrogen already. Combine it with Carbon and call it Kerosene. Methane or Propane.

Online A_M_Swallow

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RE: Griffin speech - EELV would not work for Constellation
« Reply #86 on: 03/30/2008 06:13 AM »
Keeping things simple, a 100 mT (reusable) spacecraft that goes from EML2 to low Mars orbit (LMO) and returns.  In addition 100 mT of cargo is delivered to Mars orbit.  Total 200 mT.
The high delta-v needed (13.47 km/s) to go from the Earth's surface to EML2 is ignored.

Hydrogen engine has an ISP of 462.
Kerosene engine has an ISP of 327.
If used the SEP ferry has a dry weight of 15 mT and an ISP of 2750.  The ferry returns empty.
Delta-v is the same both directions = 0.14 + 0.6 + 0.9 + 0.2 + 0.3 + 0.9 = 3.04 km/s


All hydrogen

Return 100 * exp(3040 / (462 * 9.81)) = 195.6 mT
Out (100 + 195.6) * exp(3040 / (462 * 9.81)) = 578 mT
Hydrogen propellent = 578 - 200 = 378 mT


All kerosene

Return 100 * exp(3040 / (327 * 9.81)) = 258 mT
Out (100 + 258) * exp(3040 / (327 * 9.81)) = 923.5 mT
Kerosene propellent = 923.5 - 200 = 723.5 mT


Hydrogen with SEP Ferries for cargo and return fuel

Return 100 * exp(3040 / (462 * 9.81)) = 195.6 mT
Return hydrogen propellent = 195.6 - 100 = 95.6 mT
SEP return 15 * exp(3040 / (2750 * 9.81)) = 16.79 mT
Return SEP propellent 16.79 - 15 = 1.79 mT

Out 100 * exp(3040 / (462 * 9.81)) = 195.6 mT
Out hydrogen propellent = 195.6 - 100 = 95.6 mT
SEP out (16.79 + 95.6 + 100) * e^(3040 / (2750 * 9.81)) = 237.7
Out SEP propellent = 237.7 - (16.79 + 95.6 + 100) = 25.3 mT

Total hydrogen propellent =  95.6 + 95.6 = 191.2 mT (plus boil off)
Total SEP propellent = 1.79 + 25.3 = 26.1 mT


Kerosene with SEP Ferries for cargo and return fuel

Return 100 * exp(3040 / (327 * 9.81)) = 258 mT
Return kerosene propellent = 258 - 100 = 158 mT
SEP return 15 * exp(3040 / (2750 * 9.81)) = 16.79 mT
Return SEP propellent 16.79 - 15 = 1.79 mT

Out Return 100 * exp(3040 / (327 * 9.81)) = 258 mT
Out kerosene propellent = 258 - 100 = 158 mT
SEP out (16.79 + 158 + 100) * e^(3040 / (2750 * 9.81)) = 307.6
Out SEP propellent = 307.6 - (16.79 + 158 + 100) = 32.81 mT

Total kerosene propellent =  158 + 158 = 316 mT
Total SEP propellent = 1.79 + 32.81 = 34.6 mT


The chemical fuel saved weights more than the SEP ferry.

Offline alexterrell

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RE: Griffin speech - EELV would not work for Constellation
« Reply #87 on: 03/30/2008 09:21 PM »
Quote
Norm Hartnett - 23/1/2008  1:30 PM

This speech is one of the reasons I respect Dr. Griffin. The man can really put together a good speech and this year he has done several of them. I still consider him one of the most dynamic leaders NASA has ever had.

I would like to challenge both the DIRECT group and the EELV group to respond to this speech on a point-by-point basis.
Good luck.

Some challenge. I appreciate Griffin's reasoning. I won't do a point by point rebuttal, but some points to consider (numbers are approx):

1. Ares Lift requirement was 23.3 tons? Where did this come from? The Ares 1 selection was made before Orion was specified, so 23.3 tons seems a bit odd. Why not reduce the size of Orion? Orion has double the volume of Apollo, for 33% more crew. OK - I know Americans have got bigger over the last 40 years, but that's a big increase. So why not de-size Orion? This is a bit like a factory house builder deciding to make standard modules 43 feet long when ISO containers are 40 feet.

2. The EELV people now claim that 23.3 tons can be done. Not sure who to believe, but they should know.

3. Safety: The premise was that the SRB had one accident in 200+ flights, and was therefore safer than the EELVs. In reality, Ares I is a new launch vehicle and claims about its safety are just that: claims. Next point: In simple terms, man rating means take a relatively reliable rocket and ensure that in the event of failure, the crew will probably survive. On that latter point, solid rockets don't do very well.

4. Heavy lift requirement, not a point solution for LEO access: There's nothing that can't be delivered in 20+ ton modules.

5. Cost analysis: David Smith posted the CBO estimates elsewhere in this thread and show Ares as the most expensive option.

http://www.cbo.gov/ftpdocs/76xx/doc7635/10-09-SpaceLaunch.pdf

  CBO’s results show total costs for development and operation in Table E2 page 51:

  Alternative 1: Delta+ = $27.9B
  Alternative 2: Atlas+ = $26.1B
  Alternative 6: Ares I & V = $32.4B

I think this is false. The alternative is for, say, 4 Ares V and 2 Ares 1 launches, per period (1-2 years?), versus say 24 EELV launches, of which 2 are human, 2 are precious cargo, and 20 are fuel and Earth Departure Stages. You put that out to tender with enough notice and I assure you the price of commercial launches will come down. Even for the EDS tenders (where a launch failure is acceptable if backups are made), Atlas might win round 1. SpaceX might win rounds 2 and 3. Someone you've never heard of might win Round 4. At a cost much lower than current Atlas costs, let alone NASA launch costs.

5. Storing Hydrogen: Griffin presented this as a problem for Mars missions. But single launch does nothing here as the mission is multi-year anyway. So I assume this is a lunar mission problem. On Earth, its pretty clear that using hydrogen doesn't make sense. If we found a big hydrogen well, we'd turn it into something useful like methane. So using methane, propane or kerosene increases the mass to LEO by what: 30%? There is no way, including development costs, that Ares V will be less than 130% the cost of Proton or Falcon 9H, and probably not Atlas V and Delta IV heavy.

Even for a Mars mission, according to AM Swallows calculations (no aerobraking or ISRU), 723 tons of kerosene/LOx on Falcon 9 will be cheaper than 378 tons on Ares V.

6. Future Proofing: Like it or not, I think Obama's the favourite for President, and then its probably bye bye Ares V. I think the development of a market providing multiple options in 20-25 ton class, at a descent rate would be a much better future proofing legacy.

Just some thoughts ....

Alex


Offline Lampyridae

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Re: Griffin speech - EELV would not work for Constellation
« Reply #88 on: 03/31/2008 05:49 AM »
There are other things to feed NTRs... such as Ammonia, Isp of about 600 compared to 800 for LH. That would do for return propellant.
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Offline neviden

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Re: Griffin speech - EELV would not work for Constellation
« Reply #89 on: 03/31/2008 04:23 PM »
Quote
Lampyridae - 31/3/2008  7:49 AM
There are other things to feed NTRs... such as Ammonia, Isp of about 600 compared to 800 for LH. That would do for return propellant.
In that case they are better of with simply using chemical rockets. NTRs are borderline useful as it is with 800 s.

If NASA thinks about going nuclear then NEP presents much better option. But if they would develop electric propulsion system in MW range, they could even remove the need for nuclear reactor and go with SEP.

Offline clongton

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Re: Griffin speech - EELV would not work for Constellation
« Reply #90 on: 03/31/2008 05:19 PM »
Quote
neviden - 31/3/2008  12:23 PM

Quote
Lampyridae - 31/3/2008  7:49 AM
There are other things to feed NTRs... such as Ammonia, Isp of about 600 compared to 800 for LH. That would do for return propellant.
In that case they are better of with simply using chemical rockets. NTRs are borderline useful as it is with 800 s.

If NASA thinks about going nuclear then NEP presents much better option. But if they would develop electric propulsion system in MW range, they could even remove the need for nuclear reactor and go with SEP.
I have posted a reply to this over in a more appropriate thread. Let's try to keep on topic.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9905&posts=128#M263546
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Lampyridae

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Re: Griffin speech - EELV would not work for Constellation
« Reply #91 on: 04/01/2008 01:36 AM »
OK, back on track...

While LH, either for chemical engines or NTR, is a really good idea for propulsion but a pain to store, I still don't think it's necessarily a showstopper for an EELV solution. The same anti-boiloff technology, as others have pointed out, can just as easily be redirected to EELV. What I think is the real issue is the possibility of a LV failure and some critical component winding up in the ocean with a launch window 3 months away and the LV fleet grounded while the review board figures out what's wrong.

You are putting all your eggs in one basket with a big launcher, but unlike eggs you can't make a Mars ship omelette with 5 eggs instead of 6. ISS is a 4 egg omelette when it was meant to be 6, after all. And it's still not ready to be served.

That being said... (I hate it when I shoot down my own arguments) you can still have backup modules on the ground and only one extra LV waiting to go, as opposed to two complete Mars ships and one big LV ready for LON. But I don't think we will have the money for spare spacecraft anyway.

Now, with the Europeans and Russians, neither seem about to stump for a new, larger launcher but both are keen on the moon. The only approach I've ever seriously heard is along the lines of EELV.
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Offline neviden

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Re: Griffin speech - EELV would not work for Constellation
« Reply #92 on: 04/01/2008 11:50 AM »
Quote
Lampyridae - 1/4/2008  3:36 AM
You are putting all your eggs in one basket with a big launcher, but unlike eggs you can't make a Mars ship omelette with 5 eggs instead of 6. ISS is a 4 egg omelette when it was meant to be 6, after all. And it's still not ready to be served.
I don't get the egg omlette metaphor. Mars ship could be built like ISS. You would need quite a few pieces, but there is no reason why any single piece should have to weigh more then 20 mT empty.

The only reason why ISS is still not served is that NASA *must* use the Shuttle with its low flight rate and year long shutdowns following accident. If the 20 mT pieces that the Shuttle delivers to the ISS were built to be launched on regular rockets you would have built it ages ago. Even shuttle shutdown wouldn’t affect ISS construction since you could simply use any number of other 20 mT rockets on the market.

If you would go with “chemical only / use once” system you would initially need quite a lot of 20mT rockets. This number could be cut drastically with the use of depot, long term cryogenic storage, tugs, SEPs, ISRU,.. That way NASA would end up with reusable transportation infrastructure that could reduce costs in the long run, instead of moon littered with abandoned landers.

Quote
Lampyridae - 1/4/2008  3:36 AM
Now, with the Europeans and Russians, neither seem about to stump for a new, larger launcher but both are keen on the moon. The only approach I've ever seriously heard is along the lines of EELV.
It’s no wonder they don’t want that. They don’t want to repeat US experience of ending up with *very* expensive system that has no use beyond human spaceflight. Even human spaceflight for the sake of human spaceflight has a problem of convincing taxpayers that it’s good idea to spend money on it.

The only way European and Russian will end up on the moon is if their engineers develop cost effective solutions to do that. Big rockets are very useful and convenient, but they aren’t exactly cost effective.

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