Author Topic: DIRECT v2.0 - Thread 3  (Read 1123359 times)

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #400 on: 01/19/2009 08:42 pm »
More unsubstantiated ad hominem that do not correspond to my personal experiences with him.

It sounds like you've been lucky to have good experiences with him.

But there are plenty of people out there who have seen the other side of the coin.   I've spoken with many who have been shouted at, berated for suggesting alternatives, who have been thrown out of his office and who have had threats handed down because of him.   I've spoken with 6 different people who actually lost their jobs due to him.

I have accounts from a lot of people on our team who have witnessed an unchecked ego in what should be a professional environment where it is completely innappropriate for ego to ever be allowed to run rampant.

The infamous "I'm the smartest person in the room" meeting -- I know three people who witnessed that and they all tell the same story of a guy on a total ego-trip.

I'm glad you got to see the nice side of him.   I'm glad there *is* a nice side.   But there are too many accounts otherwise for me to think that coin is single-sided.


But this isn't a useful subject to dwell upon.   He's gone.   None of this matters any more.   End of story.   We need to get focused on the future.

Ross.
« Last Edit: 01/19/2009 08:59 pm by kraisee »
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Offline jarmumd

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Re: DIRECT v2.0 - Thread 3
« Reply #401 on: 01/19/2009 09:11 pm »
We believe that due to its heritage to flying systems, that the Jupiter will fundamentally be at one end of that particular spectrum and that Ares-I will be at quite the other.


BTW, some of our engineers have already produced some low- to medium-fidelity Pro-E models of the Jupiter vehicles which they have been using for FEM work in aerodynamic and load analysis.   Exactly what & how, I don't personally know the details -- they've just told me that's what they've been doing.   I would hope that if we are ultimately selected, those models would quickly begin to 'do the rounds' so that all the other departments can start gathering some initial data just to get the ball rolling for the Pre-DAC, while higher-def versions are created.   Hopefully that will help to give everyone a step-up on the long road whenever the time comes.

Ross.

I suppose the distinction is in how much work you must do to a design to get it to work vs. that tool you use to do the design.  No matter what, our tools need updating regardless of chosen vehicle.  And as good as heritage is, as I said, the heritage models of the ET don't help you in analysis world, and many of the heritage SRB models have poor fidelity.  This means that even though they worked for shuttle (and under duress the could work for Direct), they really need to be updated to better represent the actual hardware.  Not to give you guys more ammo, but things on this side of the fence are really different from what many of you think... it can be scary how we even got this far...

(of course this is a detail, the real value to Direct is the heritage infrastructure needed to make these parts)

Without going into details, could you find out what parts they are making with pro-e and which parts they are using legacy FEM's for?  And if they are using an in-house code for loads analysis?

It's selfish, but if I know that your analysis was done well, that inspires confidence that there are no showstoppers in developing Jupiter.

Thanks, Marc

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #402 on: 01/19/2009 09:18 pm »
The happens, incidentally, with Jupiter 232 as well, if built. Both are going to be very difficult for a commercial launcher to compete with on a commercial launcher price determined by average cost plus profit.

But never the twain shall meet.   The Jupiter-232 won't compete with the EELV's -- it's illegal for a start.   Visa versa, the EELV's won't actually compete with the Jupiter-232 either.   It's not illegal, but it still won't happen, largely because there just isn't an existing EELV which can lift as much payload as a Jupiter-232.   They're in two totally different classes, so there is no competition anyway.   A pickup truck just isn't in the same class as an 18-wheel juggernaut.   They aren't rivals -- they actually compliment each other.

But nobody really cares because there will be more than enough work to keep everyone reasonably happy.

As my colleague Stephen Metschan said a while back;   This program shouldn't be about making any one company or even a small sub-set of companies 100% happy as was done with Ares.   It should be about making more than 80% of the industry more than 80% happy.

Everyone knows that a degree of compromise is healthy.   For example, Boeing knows that they won't ever get all the contracts.   They know that Lockheed and ATK are going to have to get a share too because the politics works behind the scenes and always will.   Visa versa all the other companies also know the same.   They know that they're fighting for the largest share they can possibly get of course, but they know there will be compromises and that the other companies are not going away.

What we're trying to do is work within that existing (largely political) framework.   We're trying to identify and present logical solutions where everybody would get a nice healthy share of the available business -- a portion they can each be happy and satisfied with, while all the others can also be happy too.

The fundamental aim is to ultimately get a collection of of companies and political support, each of which can get behind this plan as a reasonable, profitable and sound solution for their company.   If we can get each company to look at it that way, we end up with a loose consortium of like-minded companies who are willing to cooperate together in common cause, and we don't leave anyone screaming from the sidelines.   There is nothing stronger than that in this business.


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Likewise, if NASA is using EELVs in large numbers to fill a depot, DOD is going to want NASA to pick up an appropriate share of their fixed costs.

That is already factored into every 'sale' already -- including all NASA flights.   The $136.2m contract to launch LRO on an Atlas-V 401 included a share to cover a portion of the fixed costs for Atlas too.   That's just SOP.

Ross.
« Last Edit: 01/19/2009 09:36 pm by kraisee »
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Offline Lobo

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Re: DIRECT v2.0 - Thread 3
« Reply #403 on: 01/19/2009 09:44 pm »
The big problem with the SSME is that it is expensive to just toss it away after each mission.
Is there any way to recover the SSME? Jupiter has all of that extra lifting capability, couldn't some type of recovery system be developed? I'm thinking along the lines of having the SSMES attached to a pod on the bottom of Jupiter that would then be jettisoned from the core.

I'm no expert is such things, but I think the major problem with this is not designing a rocket mount that could jettison so the rocket motors could be recovered, but is that by the time you'd jettison it, you are in LEO going 17,500 MPH.  With the shuttle, the SRB's jettison really at about suborbital level, then the SSME's continue to burn with the ET to get the Shuttle to orbital velosity.  So a detatchable SSME pod at the bottom of the new ET would just burn up upon rentry.  Trying to equip it with some sort of heat shield would obviously be impractical.  With the Shuttle, you knew you could retreave the engines so you could make a more complex, high-tech engine that was expensive.

The only practical I could see to do that is to go with liquid boosters that could be throttled with expendable rocket motors, and basically the core would be burning 100% to get suborbital, with the boosters throttled back to conserve fuel, then a SSME pod could be jettisoned, and the boosters turned up for orbital insertion.  But now you can't recover your boosters as they'd burn up on reentry, so you are back to square one.
Maybe that would be a little cheaper, but likely it'd be more like a wash, with the added complexity of jettisonable engines on the core.

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #404 on: 01/19/2009 09:59 pm »
it can be scary how we even got this far...

I've seen some of the SRB load analysis tools used for Shuttle.   It was a really old computer simulation which must have dated back to ~1980 or so and gads knows what computer was running it, some piece of arcane wizardry no doubt.   It was pretty low-fi, but was still a mesh which you'd recognize today.   I would bet it was state-of-the-art when it was produced, but today I'm betting its one of the 'scary' things you're referring to :)


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Without going into details, could you find out what parts they are making with pro-e and which parts they are using legacy FEM's for?

I've never seen it myself.   They're at MSFC, I'm in Florida.   I'm also probably not allowed to see it anyway.   But from extensive talks with the guys I understand they have worked up models for all the major elements; the SRB's, the Core Stage, the Interstage, the Upper Stage, Orion, LAS and a variety of different payload fairings too -- essentially everything we should need.   It's most definitely not detailed down to every nut & bolt, but is sub-element (LOX Tank, Intertank, LH2 tank).   Material strengths are based on current Shuttle structures, not modified ones (although the LOX tank structure is based on the LH2 tank).   My understanding is that this was done so they could get a baseline fixed in existing hardware.   They've talked me through what they're trying to do, so I 'kinda' grok it, but you probably understand the nuances of that far better than I.


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And if they are using an in-house code for loads analysis?

I don't even know what those are, so I'll have to ask for you.


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It's selfish, but if I know that your analysis was done well, that inspires confidence that there are no showstoppers in developing Jupiter.

I can understand that.   My only concern here is to ensure I don't give away anything which might accidentally identify them.   I don't think I have any such thing which even could, but protecting these people's identity has to be my #1 priority.   Hope you understand.

Ross.
« Last Edit: 01/19/2009 10:01 pm by kraisee »
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Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #405 on: 01/19/2009 10:07 pm »
The big problem with the SSME is that it is expensive to just toss it away after each mission.
Is there any way to recover the SSME? Jupiter has all of that extra lifting capability, couldn't some type of recovery system be developed? I'm thinking along the lines of having the SSMES attached to a pod on the bottom of Jupiter that would then be jettisoned from the core.

I'm no expert is such things, but I think the major problem with this is not designing a rocket mount that could jettison so the rocket motors could be recovered, but is that by the time you'd jettison it, you are in LEO going 17,500 MPH.  With the shuttle, the SRB's jettison really at about suborbital level, then the SSME's continue to burn with the ET to get the Shuttle to orbital velosity.  So a detatchable SSME pod at the bottom of the new ET would just burn up upon rentry.  Trying to equip it with some sort of heat shield would obviously be impractical.  With the Shuttle, you knew you could retreave the engines so you could make a more complex, high-tech engine that was expensive.

The only practical I could see to do that is to go with liquid boosters that could be throttled with expendable rocket motors, and basically the core would be burning 100% to get suborbital, with the boosters throttled back to conserve fuel, then a SSME pod could be jettisoned, and the boosters turned up for orbital insertion.  But now you can't recover your boosters as they'd burn up on reentry, so you are back to square one.
Maybe that would be a little cheaper, but likely it'd be more like a wash, with the added complexity of jettisonable engines on the core.

Unfortunately all these things reduce performance and that's hurts your mission effectiveness.

We've decided to use the existing reusable boosters because they're ready-to-go and don't cost any huge sums in development terms, and the rest is (relatively) low-cost disposable hardware designed to be disposable.   It's not as fancy, but it should be reliable & safe and is intended to be affordable enough to be used a reasonably healthy number of times each year.

It might be possible to come up with a good upgrade in the future to allow J-232 Cores to be recovered, perhaps.   But we don't have to have it, so we're keeping it as simple as possible for now.   But if some bright spark figures out a way to do it without hurting Lunar performance, bring it on.

Ross.
« Last Edit: 01/19/2009 10:09 pm by kraisee »
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Offline Lobo

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Re: DIRECT v2.0 - Thread 3
« Reply #406 on: 01/19/2009 10:08 pm »

Hi Lobo,
   Those diagrams were actually produced back around the v1.0 > v2.0 switch around in early 2007 IIRC.   They're not as up-to-date as they ought to be (I need a handful of 30 hour days!).   We were very interested in the possibility of a 2-launch LOR-LOR mission around that time, but when we ran the numbers through the computer we found that in practice, the performance wasn't so hot :(

   Essentially you lose quite a lot of total performance by having to drag the mass of the second EDS thru TLI as well.   You've got a fixed CEV mass, a variable LSAM which is dependent on the propellant/EDS mass in LEO and only a finite amount of propellant.   The extra EDS mass depletes the total payload throw mass thru TLI and results in a smaller LSAM inserted into LLO.

   There were a variety of compatible propellant transfer options to make maximum use of the throw-capacity, and there were even options considered for the EDS to perform the LOI burn in some instances (for CEV, if not for the LSAM).   But the total performance never quite reached the levels of the current connect-mode EOR-LOR approach and the LEO Propellant Depot arrangement blows its sock right off, so we set the LOR-LOR architecture aside.


   The place where that mission profile is still worth keeping in the back pocket is in case we ever develop a reusable Lander.   In that future scenario, the LSAM would be launched to Lunar Orbit by a single J-232.   It can then be used 'x' times before needing to be replaced.   It would be refueled (probably by Lunar ISRU) and so the only hardware which must travel from Earth is the Orion and whatever science packages the crew is bringing along.   Each of those missions can then also be launched on single J-232's too.

   Its just one of the many different paths which we could take in the future.   But the LOR-LOR work which we did would apply quite well to it.

Ross.

Thanks for the info Ross.  It's something I'd been thinking about, so was just wondering what the pitfalls of such an idea were.

Real quick, I keep hearing the "propellent depot" term thrown around, but must have missed the orginal discussion about it.  What's the Cliff's Note's version of that that is?  A fuel tank in LEO?  In Lunar Orbit?
Also, what are the difficulties in transferring fuel in space?  Is it done by pressure? (in which case you could only load until the tanks were equalized, leaving a lot of propellent in the source left).  Or with Turbopumps?  Would that add a lot of cost/complexity to the equipment?

The reusable Lander is an interesting idea.  No reason to expend that whole vehical every time you have a mission.  What's the status on an ISRU method of refuelling the LSAM?  A long way off?
If so, the fuel could still be brought from earth.  Perhaps the EDS could be design with enough extra propellent to refuel the LSAM upon LOR?
Meaning, if you were only boosting Orion to Lunar Orbit, would you have enough extra weight capacity on a J232 for extra tanks on the EDS for the LSAM in a single J232 launch?
That'd sure be a cost saving if you can do a full Lunar Mission with 1 launch instead of two.  And you'd forgo all LEO docking, and the whole uppersage of the J232 with EDS and Orion would boost right to LOR with the LSAM, fuel it, then jettison the EDS.
The process could be further simplified if you could fuel the LSAM through the docking ring on Orion.  Then you only need one docking maneuver on the whole trip (until returning from the surface anyway) 



« Last Edit: 01/19/2009 10:26 pm by Lobo »

Offline zapkitty

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Re: DIRECT v2.0 - Thread 3
« Reply #407 on: 01/19/2009 10:20 pm »
It might be possible to come up with a good upgrade in the future to allow J-232 Cores to be recovered, perhaps.   

Come on... you know you want to do it... you know it's the right thing to do... recycle the tanks on orbit to build a station/shipyard/depot combo near equatorial plane and scavenge the engines for reuse in orbit or to be dropped in dump boxes back to Earth... you know you want to do it...   :D

Offline zapkitty

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Re: DIRECT v2.0 - Thread 3
« Reply #408 on: 01/19/2009 10:34 pm »

Real quick, I keep hearing the "propellent depot" term thrown around, but must have missed the orginal discussion about it.  What's the Cliff's Note's version of that that is?

Yep. The point being that it generally takes all of the propellant of the final stage of a launcher to make LEO...
but if you had prop in orbit ready to refuel that stage then it, and your very expensive spacecraft on that stage, could go a lot further a lot faster and do a lot more... a value all out of proportion to the extra cost of getting the extra fuel in orbit in the first place.

It's a very old and very simple principle, and the space scientists of 60 years ago would be shocked that we're not doing it in the 21st century... just before they died of collective apoplexy upon realizing that we still build and test our interplanetary ships on the ground.

Offline MP99

Re: DIRECT v2.0 - Thread 3
« Reply #409 on: 01/19/2009 10:40 pm »
...there were even options considered for the EDS to perform the LOI burn in some instances (for CEV, if not for the LSAM).   But the total performance never quite reached the levels of the current connect-mode EOR-LOR approach and the LEO Propellant Depot arrangement blows its sock right off, so we set the LOR-LOR architecture aside.


Ross,

once you have a Propellant Depot, would you use this to push heavier loads through to the Lunar surface?

Would EDS then perform the LOI burn?

cheers, Martin

Offline MP99

Re: DIRECT v2.0 - Thread 3
« Reply #410 on: 01/19/2009 10:56 pm »
But this isn't a useful subject to dwell upon.   He's gone.   None of this matters any more.   End of story.   We need to get focused on the future.


Handing down anecdotes about behaviour to underlings is one thing, but you (DIRECT) are definitely more persuasive when you stay away from past tussles.

You needed to make your point regarding an independent review, but I think you've done that now.

cheers, Martin

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #411 on: 01/19/2009 11:01 pm »

This happens, incidentally, with Jupiter 232 as well, if built. Both are going to be very difficult for a commercial launcher to compete with on a commercial launcher price determined by average cost plus profit.

No commercial launcher will ever have to compete against either the Ares or the Jupiter. It is against the law for NASA to ever compete against any commercial launcher for any kind of commercial payload. None of the commercial launchers will ever have to concern themselves with this, no neither should we. It's just not in the mix and not worth bringing up.

NASA, however, is not prevented from delivering payloads to itself in LEO, and a good thing to at the current state of the art.

So NASA is still free to consider the tradeoffs between delivering propellant to a depot for its use by Ares V as opposed to other methods. If it uses the Ares V, it incurs the marginal cost. If it buys 15 Falcon 9s, it pays the price SpaceX can make a profit at, which is probably considerably more than the marginal cost of one Ares V.

EELVS will probably cost even more per ton of payload, but are operational today with demonstrated reliability, unlike Falcon 9.

This leave aside the question of tug operation between the depot and the payload delivered to LEO, which adds a lot to the cost of delivering payloads to ISS. It seems likely that 15 smaller tug missions cost more than one big one.
« Last Edit: 01/20/2009 12:59 am by Will »

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #412 on: 01/19/2009 11:11 pm »
Real quick, I keep hearing the "propellent depot" term thrown around, but must have missed the orginal discussion about it.  What's the Cliff's Note's version of that that is?  A fuel tank in LEO?  In Lunar Orbit?

In brief:   DIRECT's baseline mission profile uses a 'connect mode' profile in LEO.   It doesn't need any Propellant Transfer of any kind.

We plan an 'advanced upgrade' to take over as soon as the tech can be developed though.   That revolves around a Cryogenic Propellant Depot, located in LEO with a capacity somewhere between 300-400mT of LOX/LH2.

Effectively that removes the payload limitations for Lunar missions.   As long as there is sufficient fuel, you can launch more than 100mT of *dry* spacecraft on a single J-232 and fill both it and the EDS up at the Depot.   The theoretical throw-mass thru TLI is somewhere the silly side of 300mT and I can't foresee ever need the full capabilities.

But the Depot enables larger Lunar missions.   There are fair reasons to consider something like a 75mT or even a 100mT LSAM as a logical upgrade.

Better still, a Depot is a great enabler for Mars missions.   With a single Depot able to throw more than 200mT of payload at Mars, we have an architecture which will allow us to go there (and NEO's too) even before we develop any Nuclear Propulsion technologies.

Later, once we have such Nuclear Propulsion systems a slightly different Depot would be able to provide in-space refueling for them too -- allowing much greater re-usability for all the space hardware we develop purely for in-space use.   Transit Habs, Propulsion Modules, cargo containers etc. would all be reusable, not disposable.

And eventually, once we mature ISRU technologies to industrial scales, we can deploy Depot's to the moon so vehicles can top-off with LOX/LH2 there, or maybe to Mars where Methane/LOX might be a better combination.

Phobos also offers some very interesting ISRU opportunities too, and its close proximity to Mars would make it a reasonably good staging area too.


The Depot is really about creating the basic building blocks of a new infrastructure -- the National Highway System -- for accessing the entire Solar System eventually.


The best bit -- the International partners make valuable contributions by taking the costs of Propellant launches off of NASA's shoulders.   Yet the US doesn't ever have to relinquish any of the strategic 'car keys' to anyone else.   The partners all reap benefits too.   The space-faring ones in particular, also improve their own programs as well (which is their entire purpose) because they'll boost their own flight-rates too.   Everyone wins.


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Also, what are the difficulties in transferring fuel in space?  Is it done by pressure? (in which case you could only load until the tanks were equalized, leaving a lot of propellent in the source left).  Or with Turbopumps?  Would that add a lot of cost/complexity to the equipment?

Apollo Applications did a huge amount of research into this.   There are quite a few different methods actually.   Each has its own set of unique pro's and con's.

The one I personally like is a simple pressure-based system.   A little of the boiled-off gas inside the tank is bled-off to be used as extremely gentle thrust (0.004g) for propellant settling to place all the fuel at one end of the tanking.   The receiver tank is essentially de-pressurized.   The delivery tank is pressurized to just 4psi -- and is maintained using helium or boiled-off gas.   By placing the receiver tank 'below' the delivery tank (in respect to the low-g thrust) and by using just a 2" OD pipe (very small indeed), this is sufficient to transfer 100 metric tons of LOX and LH2 in roughly 60 minutes.

I love the simplicity of that approach.   It wastes a tiny bit of LH2 thru the thrusting, but the forces are so small they would be of no concern to something like a CanadaArm.


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The reusable Lander is an interesting idea.  No reason to expend that whole vehical every time you have a mission.  What's the status on an ISRU method of refuelling the LSAM?  A long way off?

Yes.   A long way off.   Got to get the outpost operational so they can handle all the maintenance.   Got to land the regolith sorting and storage
systems.   Got to land processing anf refinement equipment.   Got to land enough of all that so as we can make large quantities, not laboratory quantities.   Got to develop a method of getting the fuel off the Lunar surface cheaply, reliably and safely.   By the time all that is done, we can easily have the Depot ready and waiting in High Lunar Orbit.


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If so, the fuel could still be brought from earth.  Perhaps the EDS could be design with enough extra propellent to refuel the LSAM upon LOR?

Leave that to commercial operators to figure out.   They'll be very innovative and cost-effective with their solutions.


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Meaning, if you were only boosting Orion to Lunar Orbit, would you have enough extra weight capacity on a J232 for extra tanks on the EDS for the LSAM in a single J232 launch?

Probably not.   You could get the EDS to probably perform most, if not all, of the LOI burn though.   That's a potential efficiency to be examined more closely.


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That'd sure be a cost saving if you can do a full Lunar Mission with 1 launch instead of two.  And you'd forgo all LEO docking, and the whole uppersage of the J232 with EDS and Orion would boost right to LOR with the LSAM, fuel it, then jettison the EDS.
The process could be further simplified if you could fuel the LSAM through the docking ring on Orion.  Then you only need one docking maneuver on the whole trip (until returning from the surface anyway)

The LEO Depot enables that.   It still needs to be filled -- but that's no longer a cost which the US has to pay.   In fact, it ends up being a lucrative Foreign Trade which generates new income for the US.   What's not to like? :)

The Lunar Depot is really only useful when ISRU is fully operational.   Surplus could be sent from Earth, but it ought to be self-sustaining.

Mars Depot similarly.
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Offline Lobo

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Re: DIRECT v2.0 - Thread 3
« Reply #413 on: 01/19/2009 11:16 pm »

Ben, I need to correct a few bits there.

We propose building a 'cradle' which we refer to as an SSPDM (Space Shuttle Payload Delivery Module) which would be designed to carry one of the standard Shuttle/ISS MPLM's to orbit one last time.   The SSPDM may or may not have an integral RCS system -- specifically depending on Orion's capabilities.   The SSPDM would be a disposable unit for carrying any remaining Shuttle Payloads one last time.   Once the payload (MPLM in this case) is finished with, it would be taken away by the accompanying Orion and placed into a safe orbit where it would burn up in the atmosphere.   The Orion would safely return home alone.

The SSPDM is also planned to be the basis for launching a future Orion-based Hubble Servicing Mission somewhere in the 2014 time-frame too.   After that mission the SSPDM would either be disposed of safely, or would be fitted with its own guidance and control systems and would be placed into an orbit compatible with Hubble, but a few hundred miles distant.   There it would remain, along with all the tools needed to perform any future servicing missions, ready for an Orion crew to dock with and bring back to the telescope once again.

We always liked the idea of the un-crewed Orion being an option for cargo-only deliveries and cargo down-mass capabilities.   Theoretically at least, a cargo-only variant of Orion could still be produced -- although neither CxP nor DIRECT have a budget allocation for it in the plans at this time.   It remains an option though.

And currently our suggestion is to utilize the slightly larger Delta-IV Heavy Upper Stage for the Lunar Flyby mission in December 2013 (45th anniversary of Apollo 8).   The reason being that the DIVHUS has a greater propellant load than the Centaur-V1 and therefore a higher total impulse for that mission.   A side-effect of this choice to use the Delta hardware is that together with the human-rated RS-68's, the Jupiter would cover more than half the total costs of human-rating the Delta-IV Heavy for human use -- making it a very cost-effective option to consider.

Hope that helps clarify the situation a little.

Ross.

Ross,

Thanks for the SSPDM diagram.
Quick question, would the J120 have enough power to boost it directly to the ISS?  Or would Orion specifally have to flip, dock, and boost with it's engine?  Not that that'd be problem, rather it'd be required for certain misssion profiles.  Just wondering if Orion could get there with the whole J120 upperstage in tact, dock with the ISS, then open the shrowd and the ISS manipulator arm could extract the payload from the SSPDM.
For such a mission it wouldn't need the airlock or arm then?
Just wondering if it would be easier to eliminate a docking maneuver if you could for ISS missions.  For Satillite servicing missions it'd of course need the airlock and arm.  Save those costs on an expendable SSPDM "tray" if you can was my thought.
Or would Orion need a SM engine burn or otherwise need to shed the shrowd getting to the ISS? 

Offline Jorge

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Re: DIRECT v2.0 - Thread 3
« Reply #414 on: 01/19/2009 11:26 pm »

Quick question, would the J120 have enough power to boost it directly to the ISS?  Or would Orion specifally have to flip, dock, and boost with it's engine?

It is not an issue of "power." The J-120 is a launch vehicle, not a spacecraft. It lacks capabilities for relative navigation, rendezvous targeting, guidance, and the precise control needed to perform rendezvous and prox ops with the station. A spacecraft/tug with the above capabilities, such as Orion is required in order to bring the SSPDM safely into proximity with the station.
JRF

Offline mike robel

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Re: DIRECT v2.0 - Thread 3
« Reply #415 on: 01/19/2009 11:34 pm »
Well, I did a little bit of modeling,  assuming we want to fuel the Jupiter EDS with 248,000 pounds of fuel, assumeing that the Falcon 9H, Atlas 5H are now available, that the Soyuz Fregat launches from French Guina, and that the Delta II is still in service, that you could fuel the things with

1 Atlas V Heavy
1 Atlas V 551
1 Delta IV HEAVY
2 Delta 2 7920H
1 Airane v
1 Soyuz Fregat

At a launch cost of about 1.26 Billion dollars at current launch prices.  With a 15% profit, it would run you about 1.5 Billion bucks to send the fuel up.

the launch vehicles were chosen based on being able to rapid fire them to get them into orbit to minimize boil off, and minimizing the launches from one pad.

8 Falcon 9H + a Delta 7920H would cut that cost by about 1/2 billion dollars, but the launch campaign would probably require 8 Months, assuming a minimum of 30 day turnaround time.  Maybe with smart processing, it could be reduced to 4...

Just my thoughts.

Offline Lobo

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Re: DIRECT v2.0 - Thread 3
« Reply #416 on: 01/20/2009 12:04 am »

Quick question, would the J120 have enough power to boost it directly to the ISS?  Or would Orion specifally have to flip, dock, and boost with it's engine?

It is not an issue of "power." The J-120 is a launch vehicle, not a spacecraft. It lacks capabilities for relative navigation, rendezvous targeting, guidance, and the precise control needed to perform rendezvous and prox ops with the station. A spacecraft/tug with the above capabilities, such as Orion is required in order to bring the SSPDM safely into proximity with the station.

Well, what I mean is this.  Just from a boosting and velosity standpoint, will the J120 give the payload enough to get it to the ISS?  Or will it require extra burns to get it there?
If not, I was wondering if you could leave the whole Orion/shroud/SSPDM assembly intact as you catch up to the ISS.  Orion's OMS would still be able to opereate to make course changes and slow down when it gets in ISS proximity.  Then it could dock with the ISS and the CanadaArm could open the shrud and remove the payload Similar to how the Shuttle does it. (unless you need a second manipulator arm on the SSPDM to do this).

And the only reason I mention this is a curiosity of the complexity of an ISS mission to deliver a new module.  Otherwise, you'd have to jettison the shrowd (or open it like Apollo did when extracting the LEM), flip the Orion and dock with the SSPDM, then flip Orion/SSPDM assembly again so Orion can use the SM engine to perform a burn.  once at the ISS, Orion would have to undock with the SSPDM, and then redock with the ISS.  Meanwhile, the ISS arm can attach to the SSPDM or the payload, but not both.  So if it captures the SSPDM so Orion can undock and redock with the station, how do you get payload out of the SSPDM?
With the Shuttle, the shuttle docks so it's payload bay is hardlocked to the ISS, then the manipulator arms of the ISS and Shuttle can remove the payload.
Of Orion is docked to the ISS, it's no longer docked to the SSPDM.  SO it seems there'd be a desire to be able to harddock to the ISS, and have the SSPDM thus locked too, so the payload can be removed.  Then the SSPDM could be jettisoned.
Perhaps the shroud could be jettisoned before it reached the ISS, but the SSPDM would still be rigidly attached to Orion, so Orion could maneuver it into the ISS.  But that wouldn't work if a main engine burn from Orion was required to get it to the ISS.

Make sense? 

Another option would be a docking ring on the opposite side of the SSPDM that could dock with the ISS while the payload was removed.  But the astronauts would be stuck in Orion while that was going on.  Then Orion would have to back out the SSPDM, jettison it, then redock with the ISS.  Seems like a lot of maneuvers overall.  Seems like it's be easier if Orion could just "tow" (not accually towing because it couldn't fire it's main engine) it to the ISS rather than "push" it there.

I know Ross was mentioning earlier that with Ares 1, Orion would have to do a SM burn to get it to the ISS.  Didn't know if that's the case with the J120.

Offline Jorge

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Re: DIRECT v2.0 - Thread 3
« Reply #417 on: 01/20/2009 12:40 am »

Quick question, would the J120 have enough power to boost it directly to the ISS?  Or would Orion specifally have to flip, dock, and boost with it's engine?

It is not an issue of "power." The J-120 is a launch vehicle, not a spacecraft. It lacks capabilities for relative navigation, rendezvous targeting, guidance, and the precise control needed to perform rendezvous and prox ops with the station. A spacecraft/tug with the above capabilities, such as Orion is required in order to bring the SSPDM safely into proximity with the station.

Well, what I mean is this.  Just from a boosting and velosity standpoint, will the J120 give the payload enough to get it to the ISS?  Or will it require extra burns to get it there?

In terms of pure orbital height, I'm pretty sure it can, though it may depend on the mass of the payload in the SSPDM.

But the ISS program establishes two boundaries, the Approach Ellipsoid and the Keep-Out-Sphere, within which visiting vehicles are not allowed until they meet certain requirements. And one of those requirements is that, starting with the first burn that takes the trajectory into the Approach Ellipsoid, all burns must be actively guided. That means the Orion, and not the J-120, must perform those burns. There are also rules about debris hazards that would preclude jettisoning the shroud while in proximity to ISS. So my take on it is that the shroud must be jettisoned prior to entering the approach ellipsoid.

Quote
If not, I was wondering if you could leave the whole Orion/shroud/SSPDM assembly intact as you catch up to the ISS.  Orion's OMS would still be able to opereate to make course changes and slow down when it gets in ISS proximity.

I don't think that's possible. The drawings I've seen from the DIRECT proposal is that the SSPDM would be mounted below the Orion OMS in the shroud. Therefore it would not be possible for the Orion to perform OMS burns until it has jettisoned with the shroud, transposed, and docked with the SSPDM.

Quote
  Then it could dock with the ISS and the CanadaArm could open the shrud and remove the payload Similar to how the Shuttle does it. (unless you need a second manipulator arm on the SSPDM to do this).

And the only reason I mention this is a curiosity of the complexity of an ISS mission to deliver a new module.  Otherwise, you'd have to jettison the shrowd (or open it like Apollo did when extracting the LEM),

I think you have that backward. The Apollo SLA panels only hinged open on flights without the LM. On all the LM flights the SLA panels were jettisoned to prevent them from interfering with LM extraction.

Quote
I know Ross was mentioning earlier that with Ares 1, Orion would have to do a SM burn to get it to the ISS.  Didn't know if that's the case with the J120.

It will be the case with the J120. Regardless of launch vehicle, all rendezvous burns would be performed by the Orion.
JRF

Offline Will

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Re: DIRECT v2.0 - Thread 3
« Reply #418 on: 01/20/2009 12:56 am »
The big problem with the SSME is that it is expensive to just toss it away after each mission.
Is there any way to recover the SSME? Jupiter has all of that extra lifting capability, couldn't some type of recovery system be developed? I'm thinking along the lines of having the SSMES attached to a pod on the bottom of Jupiter that would then be jettisoned from the core.

Something like this is possible, but it's difficult to make it cost-effective. Something similar was proposed for Boeing's original EELV bid.

Making the pod separable adds mass. Adding a heat shield for the pod to survive reentry adds mass. So do parachutes. Recovery equipment to survive a salt water splashdown or allow mid-air recovery add mass. All these reduce payload.

Recovering the pod and reconditioning it for a new flight add nontrivial costs.

A recoverable pod also make development more complex and costly.

If flight rates were high enough it might pay, but no launcher company has yet been convinced that it works for them.

HLV launchers like Jupiter and Ares V will find it particularly diificult to justify high flight rates.

Offline clongton

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Re: DIRECT v2.0 - Thread 3
« Reply #419 on: 01/20/2009 01:36 am »
The Jupiter-120 has the ability to do either:
1. Execute MECO while still "barely" suborbital with Orion doing the final orbital insertion, just like shuttle. This allows for atmospheric disposal of the ET without a de-orbit burn on the ET. This is fine if there is no payload, such as the SSPDM. But if there is, this is problematic because Orion would only have a matter of minutes to detach, translate, dock with the payload module, extract the payload module, translate again and ignite the SM engine to do the orbital insertion burn. This can certainly be done but it is on the hairy edge of timing and would need perfect execution.
2. Insert itself and the spacecraft directly into a circular orbit of the correct altitude and inclination. This gives Orion all the time it needs to detach, translate, dock with the payload module, extract the payload module and translate again before doing a translation burn to catch up with the ISS. Ulage motors can then fire on the ET to de-orbit it for atmospheric disposal, the same as Saturn.

The SSPDM has an airlock on the end where it attaches to Orion, with a docking collar at 90 degrees to the spacecraft centerline. This is what would be used to dock to the station in exactly the same manner as Shuttle does now. Payloads would be extracted from the module in exactly the same way as they are done currently with the station arm.

When the mission is over, Orion departs the station, executes the de-orbit burn, and then jettisons the SSPDM and the SM prior to re-entry, the same way Soyuz decouples. Unlike Soyuz however, explosive bolts are not used. This is a docking collar that essentially only needs to be unlocked and pushed away with springs. That's how it is envisioned. How NASA would actually design and use the SSPDM is up to them.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

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