Author Topic: Griffin speech - EELV would not work for Constellation  (Read 44532 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.  
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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.

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.

Online 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.

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