Author Topic: DIRECT v2.0 - Thread 3  (Read 1123390 times)

Offline BogoMIPS

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Re: DIRECT v2.0 - Thread 3
« Reply #300 on: 01/18/2009 09:33 pm »
Another theoretical question: how much Jupiter-120\232 can lift if it will use SSME?

Theoretical answer, based on CEPE spreadsheet (thanks PaulL):

J-120 with SSMEs lifts ~14% more J-120 with RS-68s.
J-232 with SSMEs lifts ~5% less than J-232 with RS-68s.

Remember... DIRECT's goal is to maximize the J-23x configuration, and then re-use it with as few changes as possible for the J-120.

Maximizing the J-120, then adjusting to maximize the J-23x later, costs more.  The higher-thrust, lower Isp RS-68 is a better first stage engine (probably the best hydrolox option available).  The lower-thrust, higher Isp SSME is a better SSTO engine, and would have made an outstanding air-start upper stage engine if they could have sorted that bit out.
« Last Edit: 01/18/2009 09:39 pm by BogoMIPS »

Offline spacenut

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Re: DIRECT v2.0 - Thread 3
« Reply #301 on: 01/18/2009 09:44 pm »
How much could the Direct Core with three RS-68 engines lift without the solids?  Can it do the same as the Delta IV heavy with 3 engines?  Would it need a second stage to complete the trip to orbit?

Offline Lee Jay

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Re: DIRECT v2.0 - Thread 3
« Reply #302 on: 01/18/2009 10:18 pm »
How much could the Direct Core with three RS-68 engines lift without the solids?  Can it do the same as the Delta IV heavy with 3 engines?  Would it need a second stage to complete the trip to orbit?

It would have a liftoff thrust-to-weight ratio right around 1 without a payload or upper stage.

Offline Khadgars

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Re: DIRECT v2.0 - Thread 3
« Reply #303 on: 01/18/2009 10:34 pm »

Also, there is no commercial market in space that needs a depot, what are you talking about?

Anyway, we are off-topic.

First, "in general" it is not off topic because it is part of the DIRECT architecture. See the AIAA paper.

Second, I said "create" the market. The benefits of a depot are indisputable, but the initial development and deployment/testing is cost prohibitive without a NASA contract to make it possible. Once operational however, there are several nations that will line up to take advantage of it because they cannot launch big spacecraft now because of the mass penalty of lifting all the mission propellant with the spacecraft. A single-launch Jupiter-232 mission that stopped at the depot before TLI for the mission propellant could easily triple the size of the mission hardware sent thru TLI to the moon. India, for example, could certainly send a really sophisticated lander/orbiter to Mars if it could fill its tanks in orbit before departing. Similar to you stopping at a gas station before heading out across country in your car. There will be lots of nations and corporations that will take advantage of the new availability of the "gas station" in orbit, and lots of commercial companies competing to deliver the propellant to the depot.

The DIRECT architecture isn't just the Jupiter Launch Vehicles. It is an entire approach to getting as many nations as possible out into the Solar System. It's about "enabling" mankind to take that step.

Why are you able to use propellant depots with Jupiter but not Ares?  Jupiter would be under the same law prohibiting it for commercial use.
Evil triumphs when good men do nothing - Thomas Jefferson

Offline clongton

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Re: DIRECT v2.0 - Thread 3
« Reply #304 on: 01/18/2009 10:47 pm »

Also, there is no commercial market in space that needs a depot, what are you talking about?

Anyway, we are off-topic.

First, "in general" it is not off topic because it is part of the DIRECT architecture. See the AIAA paper.

Second, I said "create" the market. The benefits of a depot are indisputable, but the initial development and deployment/testing is cost prohibitive without a NASA contract to make it possible. Once operational however, there are several nations that will line up to take advantage of it because they cannot launch big spacecraft now because of the mass penalty of lifting all the mission propellant with the spacecraft. A single-launch Jupiter-232 mission that stopped at the depot before TLI for the mission propellant could easily triple the size of the mission hardware sent thru TLI to the moon. India, for example, could certainly send a really sophisticated lander/orbiter to Mars if it could fill its tanks in orbit before departing. Similar to you stopping at a gas station before heading out across country in your car. There will be lots of nations and corporations that will take advantage of the new availability of the "gas station" in orbit, and lots of commercial companies competing to deliver the propellant to the depot.

The DIRECT architecture isn't just the Jupiter Launch Vehicles. It is an entire approach to getting as many nations as possible out into the Solar System. It's about "enabling" mankind to take that step.

Why are you able to use propellant depots with Jupiter but not Ares?  Jupiter would be under the same law prohibiting it for commercial use.

You are missing the point.
1. With Ares, there will never be a propellant depot. Ares costs too much to allow the funding to deploy one.
2. Using the depot as a customer is not the same as competing to fill the depot. Jupiter would BUY propellant from the depot and pay the commercial owner for the propellant. Jupiter would be a customer, not a supplier. If Ares costs were not so high, Ares could do the same thing.

A NASA Jupiter/Ares/Whatever can USE the depot by purchasing its product, but NASA cannot compete against the commercial launch services that are making a business out of propellant delivery. NASA is and must remain a customer, not a competitor.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Lars_J

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Re: DIRECT v2.0 - Thread 3
« Reply #305 on: 01/18/2009 11:12 pm »
You are missing the point.
1. With Ares, there will never be a propellant depot. Ares costs too much to allow the funding to deploy one.

Never? :D - Are you supposing that manned space flight will end in the next few years?? Let's have a *little* foresight here...

I personally don't see orbital fuel depots happening anytime soon, no matter what architecture is chosen for Moon flights. Ares doesn't need one. Direct doesn't need one. EELV/HLV doesn't need one. EELV doesn't need one.

In the *near* future, sending up multiple smaller and stackable and expendable departure stages will be cheaper. IMO again.

I don't think propellant depots will happen until there are commercially funded missions beyond Earth orbit. Why? Because government missions will always build a bigger launch vehicle if they need one, even if it makes no sense. A commercial enterprise will not develop a larger booster unless it has to, or it is cheaper.

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #306 on: 01/18/2009 11:36 pm »
Well here it is, my penultimate version of the J-232:

I think that's awesome.   I used to love my Lego sets!   I want one of those!!!   :)

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #307 on: 01/18/2009 11:41 pm »
If the answers come up jelly-side-down for DIRECT, is it safe to assume that cries of bias, incorrect figures, or incompetence would follow?

Point blank:   Even without Griffin at the reins, folk like Doug Cooke, Jeff Hanley and Steve Cook are still fully-paid-up members of Griffin's inner-circle.   If they have *any* way of influencing such a review it can not and will not be unbiased.   Period.

This is not a criticism of NASA as an agency.   There are an extremely large number of dedicated and skilled people within the agency whom are not biased, whom we would trust.   In point of fact, the bulk of the DIRECT Team is made from the ranks within NASA -- they *are* us.   Our key concerns focus on the cluster of people whom Mike Griffin placed in senior positions who all tow his particular chariot.   As long as these people, and a select group of others, remain in their decision making positions we feel that the rest of the agency is effectively being held hostage to a management team who have a track-record of doing everything in the book to discredit every other option -- ours inclusive.

Given the number of times each of those people has trash-talked both the DIRECT and the EELV solutions over the past three/four years, I have no faith what-so-ever that these people are capable of leading an unbiased study.   They may have been towing Griffin's line, or they may believe -- but there is just no way to differentiate.

Therefore I am willing to predict that the results *WILL* be called into question by one or more groups -- even if our isn't one of them.

This is why I believe Congress needs to order a fully Independent Study conducted outside of NASA and utilizing people who have no horse in this race.

Without that degree of true Independence, it is GUARANTEED that there will be cried of bias from whoever doesn't get selected.

Only if there is an Independent Review would all of the rival teams be able to accept the results -- even grudgingly.


My personal opinion is that CBO or GAO need to be given charge of the Review.   They have the ability to calculate the fiscal and the scheduling aspects.   They can bring in an independent company to calculate the technical aspects.   For that, we believe someone like RAND, Aerospace Corporation or Analex would be suitable.   SIAC is an option too, but they have had profitable contracts with both ATK and NASA regarding the Ares-I, so there are possible questions which can be raised regarding their impartiality.

Personally I would like a panel formed to perform the review, maybe using CAIB as a template.   I think there should be a representative on-hand from each of the factions within the panel.    As a check & balance they should be able to review the evidence of all the other teams to ensure nobody is playing unfairly and they should be able to flag any suspicious claims.   That's how I would do it if I could.

Ross.
« Last Edit: 01/19/2009 01:55 am by kraisee »
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Offline Integrator

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Re: DIRECT v2.0 - Thread 3
« Reply #308 on: 01/18/2009 11:57 pm »
MSFC Engineering proper is independent of the Ares and Constellation Project.  Let us have a crack at it and let NESC, GAO and IG keep them out of our knickers while we do our jobs. (Existing management hasn't dared to enlist us in that level of trade because they fear what will probably happen in that scenario.)
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Offline mars.is.wet

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Re: DIRECT v2.0 - Thread 3
« Reply #309 on: 01/19/2009 12:13 am »
If the answers come up jelly-side-down for DIRECT, is it safe to assume that cries of bias, incorrect figures, or incompetence would follow?

Point blank:   Even without Griffin at the reins, folk like Doug Cooke, Jeff Hanley and Steve Cook are still fully-paid-up members of Griffin's inner-circle.   If they have *any* way of influencing such a review it can not and will not be unbiased.   Period.

...

Only if there is an Independent Review would all of the rival teams be able to accept the results -- even grudgingly.

Ross.

Fair enough.  But if the new administration calls for or even allows HQ to run a transportation study, the likelihood of an indendent review in the next 12-24 months goes to just about zero.

And as many on this board have pointed out, even if DIRECT is selected by some outside group, it will have to be developed by many of those same folks and their hand-selected deputies.  Its not like 10's of Cx launch system managers will be released or reassigned to junior roles and more competent/friendly (by DIRECT standards) will be appointed.  You can't dispose of mid-level civil servants like Kleenex.

(although I'm sure everyone will say "first things first" ;-)

Offline mars.is.wet

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Re: DIRECT v2.0 - Thread 3
« Reply #310 on: 01/19/2009 12:14 am »
MSFC Engineering proper is independent of the Ares and Constellation Project.  Let us have a crack at it and let NESC, GAO and IG keep them out of our knickers while we do our jobs. (Existing management hasn't dared to enlist us in that level of trade because they fear what will probably happen in that scenario.)

See, everyone has their own version of "independent".  Well said!


Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #311 on: 01/19/2009 12:26 am »

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

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

And the one man who insisted it be done that way will no longer be there.

If I understand you correctly, you seem to be suggesting that Direct will benefit from a radical and coincidental change in how NASA operates, so that development costs will be much lower than the current model.

This seems unreasonable. The radical change may not happen. You yourself suggest that even if Griffin leaves, others of a similar mindset will remain.

And even if such a radical change happens, the benefits would not apply solely to direct. Savings in development costs will also benefit other approaches, such as Ares I/V. Or even keeping Ares I but avoiding a 100 ton to LEO HLV entirely.

If propellant depots are cost effective, then an uprated Delta or Atlas in the 27-50 ton to LEO range may be a better solution on a life cycle basis.

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #312 on: 01/19/2009 12:40 am »
If the answers come up jelly-side-down for DIRECT, is it safe to assume that cries of bias, incorrect figures, or incompetence would follow?

Point blank:   Even without Griffin at the reins, folk like Doug Cooke, Jeff Hanley and Steve Cook are still fully-paid-up members of Griffin's inner-circle.   If they have *any* way of influencing such a review it can not and will not be unbiased.   Period.

Ross.

And yet the Direct team repeatedly argues that the engineering judgement and experience of Lockheed and other contractors is superior to that of NASA, and should trump their conclusions. But why should we expect a disinterested and unbiased opinon from the very companies that would benefit from a particular decision?

Offline tnphysics

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Re: DIRECT v2.0 - Thread 3
« Reply #313 on: 01/19/2009 12:45 am »
Would it be possible to add strap-on boosters (in addition to the 2 SRBs) to the Core?

Something like a A5 CCB or a smaller solid.

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #314 on: 01/19/2009 01:16 am »
Clongton, I think that refueling PD by Ares-V will be cheaper than by 20mt LVs. Ares-V is how many Ariane-5`s? Seven?


If Ares-V costs $10 billion to develop and there are 100 flights (unlikely!) that's $100 million additional cost per flight.

Surely that makes it more expensive?

cheers, Martin

Current cost of Ares-V is more like $25-30 billion.

Current flight cost of Ares-V is more like $1,400m each.

Amortizing the development cost cross 100 flights will make Ares-V cost more like $1,650m each -- about twice the cost of Shuttle.

At a estimated cost of about $180m each for the Ariane-V's, you could afford 9 Ariane-V's.

Given the low flight rate of Ares-V I think it would take at least 25 years to achieve that flight rate though.

And this isn't how it actually works.   The development costs for Ares-V will actually have to be paid up-front before the first flights.

Ross.
« Last Edit: 01/19/2009 01:17 am by kraisee »
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Offline gladiator1332

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Re: DIRECT v2.0 - Thread 3
« Reply #315 on: 01/19/2009 02:27 am »
If the answers come up jelly-side-down for DIRECT, is it safe to assume that cries of bias, incorrect figures, or incompetence would follow?

Point blank:   Even without Griffin at the reins, folk like Doug Cooke, Jeff Hanley and Steve Cook are still fully-paid-up members of Griffin's inner-circle.   If they have *any* way of influencing such a review it can not and will not be unbiased.   Period.

Ross.

And yet the Direct team repeatedly argues that the engineering judgement and experience of Lockheed and other contractors is superior to that of NASA, and should trump their conclusions. But why should we expect a disinterested and unbiased opinon from the very companies that would benefit from a particular decision?

If I recall, the team has called for a review by an outside group...not connected to aerospace in anyway.

And they never said that Lockheed's judgement is superior to NASA, as there are also NASA engineers working on the Direct project.

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #316 on: 01/19/2009 03:07 am »
Why are you able to use propellant depots with Jupiter but not Ares?  Jupiter would be under the same law prohibiting it for commercial use.

One word:   Money.

Firstly, Ares-I and Ares-V together will cost over $30 billion to develop.   The two Jupiter's can be fielded for roughly half that figure.   That alone gives you a lot more resources to be able to fund other work.


Operationally there is also a large cost difference.   Just to meet the baseline requirement of 2 ISS, 2 Lunar Crew and 2 Lunar Cargo missions CxP requires a $3-4 billion increase to NASA's yearly budget.

That also assumes we've closed down ISS and redirected all of its ~$2bn/yr towards Lunar funding for FY2017.   If Congress mandates ISS is to be kept beyond 2016, NASA will actually need $5-6bn more every year to cover the planned costs of the Ares-based architecture.

Worse:   If that extra money doesn't turn up, we will not be able to afford to go *anywhere*.

To add development of a Depot on top of those major increases would require even more money -- The simple question is "where is that extra money to come from?


While I would love to see more money for NASA I don't think anyone seriously expects this to happen.   Congress has already refused -- for four years running now -- to supply the 'more money' which was actually promised for the VSE.   And, unfortunately, there is no sign of that changing either.


Now, during the campaign, Obama promised $2bn for NASA.   But people make the mistake of thinking that would be a yearly increase -- it isn't.   That is intended as a single one-time "shot-in-the-arm" to try to speed up Orion.

We might still get that 'shot' if we're very lucky.   But you'd have to be seriously naive to think we're ever going to get the sort of money CxP needs.

What Ares is setting up is "Apollo-Redux".   The very best scenario CxP is creating right now is a short-lived funding of Lunar missions for a few years.   The initial landings will be a big deal, but they will be followed by the inevitable fall-off in public & political support (just as we saw during Apollo) and then the questions will be raised why we are funding a program which launches only 8 Lunar astronauts, yet costs $12 billion every year.   That argument is not a winnable one: Apollo teaches us this lesson very clearly, but Ares proves some people have failed to learn the lesson.


So what we really *NEED* is a program which can afford to place 48 Astronauts on the Lunar surface every year, but which costs just $8 billion per year.   That would create a far more politically justifiable program.   Most especially if 24 of those Astronauts are from other countries.   *THAT* capability would give the US a helluva lot of political "soft power" with other world governments.



And on an $8bn budget, the Human Spaceflight Program could still afford to develop other technologies too:   Depot's, new engines, Nuclear Propulsion Systems, ISRU technologies, NEO missions and Mars missions are some of the more obvious candidates to direct funding towards.

Ross.
« Last Edit: 01/19/2009 03:42 am by kraisee »
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Offline Jim

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Re: DIRECT v2.0 - Thread 3
« Reply #317 on: 01/19/2009 03:11 am »

And yet the Direct team repeatedly argues that the engineering judgement and experience of Lockheed and other contractors is superior to that of NASA, and should trump their conclusions. But why should we expect a disinterested and unbiased opinon from the very companies that would benefit from a particular decision?

Because LM's (ULA) work speaks for itself.  NASA hasn't design a launch vehicle in over 30 years

Offline Marsman

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Re: DIRECT v2.0 - Thread 3
« Reply #318 on: 01/19/2009 03:13 am »
Just clarifying Ross' point above. Basically, the reason Jupiter can develop the depot is because it saves so much money versus Ares (on the order of ~20 billion thru 2020). Some of this extra money will be redirected towards the propellant depot and other sectors of NASA (Aero, Science, etc)

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #319 on: 01/19/2009 03:17 am »
And yet the Direct team repeatedly argues that the engineering judgement and experience of Lockheed and other contractors is superior to that of NASA, and should trump their conclusions. But why should we expect a disinterested and unbiased opinon from the very companies that would benefit from a particular decision?

Will, you haven't done your research properly.   You're making incorrect assumptions.

If you were to check the archives you will see that we have talked about this a number of times previously on the various NSF DIRECT threads.   You would also see that we have *NEVER* proposed contractors like Boeing or Lockheed-Martin be the ones performing such a review -- everyone knows that wouldn't be "Independent" either.

Everybody's work needs to be Judged fairly.   We are asking for a fair Judge to be appointed.   Any Judge with ties to Ares, EELV or DIRECT needs to recuse him-/her-self from the proceedings entirely or this simply can not be fair.

My complaint with NASA performing the review is that many people in NASA's Upper Management today have proven themselves to be in one of those camps and viciously opposed to all the others.   Therefore they are proven to be biased.   Therefore they can not be involved, or this will be patently un-fair for all involved.   If this happens it will be a dreadful waste of tax-payers money and a total waste of time for everyone involved.   In the full meaning of the phrase:   We need an "Independent Review".


Will, you should not assume such things or try to put words in our mouths.   Doing so only makes you look like one of those 'antagonists' which I talked about previously.   Unless you want to be one of those, please refrain from jumping to such conclusions in the future.

You would be better-off trying to asking us what we mean when we say such things -- get the information from the horses mouth, as it were.   The Team have generally thought these issues out very thoroughly and have almost certainly got an answer for you if you bother to ask.

You're welcome to challenge the facts, in fact I hope people will.   But challenging false assertions like you did above, does nobody any favors.   Be careful, because people will quickly get the wrong idea about you if you do it too often.

Ross.
« Last Edit: 01/19/2009 03:51 am by kraisee »
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

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