Author Topic: "Direct" Alternative  (Read 60307 times)

Offline kraisee

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"Direct" Alternative
« on: 08/30/2006 10:44 PM »
I'm going to start putting information about "Direct" in this thread instead of spreading it around.

I'd appreciate constructive analysis and feedback into the concept.

I'll start by showing a modified version of the "Stumpy" drawing presented previously, but showing "Direct" and "Direct + EDS" for comparison purposes, and Ares-V too.

Ross.

EDIT: I will also add the three previous diagrams I had already posted.
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Offline yinzer

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Re: "Direct" Alternative
« Reply #1 on: 08/30/2006 11:36 PM »
Some areas to address, in no particular order.  Is this the same launch vehicle as LV 24/25 in the ESAS report (page 420)?  Is it going to need a support tower to withstand wind loads during rollout?  (the Cd for a cylinder is 0.6, the Cd for a flat plate is ~1, pitch seems to be the relevant axis, and it looks like Direct will have more bending loads at it's base than STS).  Can you sketch a rough budget sand-chart and manifest through first lunar flight?  It feels like this requires spending a lot of money up front for launch vehicle development and then carrying the subsequent large-ish operating costs during the EDS and LSAM development and shakeout periods when there will be comparatively low flight rates.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #2 on: 08/31/2006 12:01 AM »
Quote
yinzer - 30/8/2006  7:23 PM

Some areas to address, in no particular order.  Is this the same launch vehicle as LV 24/25 in the ESAS report (page 420)?  Is it going to need a support tower to withstand wind loads during rollout?  (the Cd for a cylinder is 0.6, the Cd for a flat plate is ~1, pitch seems to be the relevant axis, and it looks like Direct will have more bending loads at it's base than STS).

I think the basic "Direct" would have less problems than STS because the wings and stabiliser of the orbiters will "catch" substantially more wind forces from most directions than the cone on the top of a fairly regular stack IMHO.

But "Direct+EDS" needs to be studied to answer the wind/bending moments.   The unfuelled EDS with the maximum 35mT payload in a 5mT shroud on top would mass 60mT or so, on top of the 'ET'.   That is roughly half the mass of the yesterday's 115mT Shuttle hanging off the side during rollback with the payload still in the payload bay, so I suspect we should be okay.

Given that the SRB mounts are designed already to sustain the "twang" during STS launch and do so repeatedly in the case of test-firing of the MPS at the Pad, I'm thinking that the stack & MLP interface can sustain a *huge* amount of latteral force.

The interface between the Core stage and EDS might be a weak-point, but that can only be answered IMHO, with detailed analysis, and I don't have those tools.   I'd say that interface is still probably a lot stronger than the three connections to the orbiter though...

If it should require a stabiliser, a much thinner umbilical tower can be mounted on the MLP, nothing like as wide or heavy as the LUT being designed for the Ares vehicles.   Something closer to the Atlas-V umbilical tower would probably be able to offer sufficient stability gains to bring everything into the 'green'.


Quote
Can you sketch a rough budget sand-chart and manifest through first lunar flight?  It feels like this requires spending a lot of money up front for launch vehicle development and then carrying the subsequent large-ish operating costs during the EDS and LSAM development and shakeout periods when there will be comparatively low flight rates.

I have the detailed budget analysis done during ESAS, but not released.   I could do a comparative rough sketch perhaps, but it'll take some time to work it out.   Haven't done one of those before...

Ross.
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Offline yinzer

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Re: "Direct" Alternative
« Reply #3 on: 08/31/2006 01:16 AM »
The wings and the stabilizer are also much lower to the ground than the area above the ET, and so generate much smaller bending moments.  The Ares I is going to require a new MLP because of the weight of the LUT; the Direct has another million pounds of SRB on the MLP during rollout, so even a small LUT could push it over the limit.

The LO2 tank will have to be redesigned to be much stronger than it currently is to support the payload and shroud.  This isn't impossible, but will increase the dry weight of the tank, which trades 1:1 with payload.  But whatever - maybe the payload goes down to 65 or 70 tons from 73.

The cost and schedule are the really critical things.  Possibly saving $1B in 2020 is much less valuable than saving $1B in 2009; being able to fly the CEV in 2011 vs. 2015 has big influences for mission safety and political support, and so on.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #4 on: 08/31/2006 04:07 AM »
The ADFT-I-1 will not require a LUT, so I suspect the stability is not actually the issue.   The huge LUT on the Ares-I MLP appears mainly to be there to provide service access.   The umbilicals don't require anything like that size of tower.

Anyway, that's getting off the subject at hand :)

I don't think the tanking will overall require much mass change.   As I said earlier, it is currently designed that the LH2 tank has to support the 115mT of orbiter hanging on the side - and that is a far more difficult proposition from an engineering PoV than mounting something above a cylindrical tank structure.

The stresses involved in hanging something piggy-back-style, like the orbiter requires a lot of internal strengthening which can now be removed.   There will have to be re-design work done, but it will be one of those 'take from here (LH2 tank), give to there (LO2 tank)' things.   From what I've been able to research, there is actually a very good chance of a slight mass *decrease* overall with the in-line configuration compared to the side-mount one.   Not much, between 1 and 2 tons, but any advantage is better than a penalty :)

As for costs, there is no way Direct would cost more to develop or operate compared to Ares-I and Ares-V together.   It should actually cost no more than Ares-V alone.   In fact, for the same limited number of missions currently being planned, you save close to $2Bn per year from about the third year of CaLV development () onwards.

Using the break-down of CLV and CaLV costs as a guideline, I've got a *rough* estimate for total costs from development through operations...

I've re-created part of the graph from the ESAS Report for the original CLV and CaLV costs to give it some comparison...   CEV costs remain the same as ESAS.   LSAM and EDS costs are the same as ESAS, but are brought forward two whole years because they utilise monies previously being used to develop the CaLV.   This means Lunar missions can start flying two years earlier for less overall money.

Both costs assume 2 operational ISS missions per year thru 2016, and 2 Lunar missions every year from inception of Lunar flights.

Using the current Ares 1.5 launch solution:   First Lunar Mission (2018) total expenditure: $104.6Bn.

"Direct" saves over $30Bn to get to the first Lunar mission, and saves more than $2Bn every year after that, to do just the same schedule of flights.   First Lunar Mission (2016) total expenditure: $72.7Bn.

Alternatively, for the same annual budget as currently being planned, 3 to 4 extra Lunar missions would be possible every year.

Ross.
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Offline MATTBLAK

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Re: "Direct" Alternative
« Reply #5 on: 08/31/2006 08:08 AM »
On the face of it; it sounds good. You are a steely-eyed missile man!! ;)
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Offline kraisee

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Re: "Direct" Alternative
« Reply #6 on: 08/31/2006 07:51 PM »
I have a feeling that there's no possibility though.

Latest info I have is that all of the Ares-I's "concerns" are as good as 'fixed' already, and NASA just committed to building the new MLP's for the Ares-I.   That's a fair-sized chunk of cash to commit IMHO, so they're firmly on their current track from where I sit, with little motivation to change course.

Ross.
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Offline wannamoonbase

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Re: "Direct" Alternative
« Reply #7 on: 08/31/2006 10:44 PM »
I am not entirely sold on the CLV being the best option but its good to be moving forward with the MLPs and CEV contract.  We can't be sure its the best direction but it s a direction so  I will gladly take it.
Excited to be finally into the first Falcon Heavy flow, we are getting so close!

Offline kraisee

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RE: "Direct" Alternative
« Reply #8 on: 09/01/2006 12:37 AM »
Yes, I don't believe "perfection" is achievable in the modern climate of economics and politics.

But I think "effective" is possible, and I consider Ares-I and V to be "effective" in their roles.

"Direct" is a better solution still, and continues to fulfill all of the political objectives too IMNSHO. ;)

Ross.
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Online mike robel

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RE: "Direct" Alternative
« Reply #9 on: 09/01/2006 01:02 AM »
Another one of my Army lessons:  A piss poor plan executed aggressively is better than a perfect plan poorly executed.  :)

Lets just get flying (after having drunk 4  bourbon and cokes to console myself after LM wins the CEV.  ).

Offline simcosmos

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RE: "Direct" Alternative
« Reply #10 on: 09/01/2006 04:58 PM »
Quote
kraisee - 1/9/2006  1:24 AM

Yes, I don't believe "perfection" is achievable in the modern climate of economics and politics.

But I think "effective" is possible, and I consider Ares-I and V to be "effective" in their roles.

"Direct" is a better solution still, and continues to fulfill all of the political objectives too IMNSHO. ;)

Ross.

At very least, *Direct* should provide a funny Orbiter addon to play with ;)

António
my pics @ flickr

Offline braddock

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Re: "Direct" Alternative
« Reply #11 on: 09/01/2006 05:11 PM »
Shesh, you've already modeled it?

Offline kraisee

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RE: "Direct" Alternative
« Reply #12 on: 09/01/2006 06:37 PM »
António very kindly agreed to make an orbiter model to demonstrate the concept.   As you can see above, he's already well into the development and is doing a *FANTASTIC* job!

It's really wonderful to see the idea 'coming to life' there :)

Ross.
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Offline AndyMc

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RE: "Direct" Alternative
« Reply #13 on: 09/01/2006 07:58 PM »
Great stuff António. If only the real ones came as fast! How long until you release some of these 'toys'  ;)

I've been a bit busy with a few of my own, based on NASA's DRM - http://gltrs.grc.nasa.gov/reports/2002/TM-1998-208834-REV1.pdf

Some more details of the add-on: http://www.aovi93.dsl.pipex.com/my_orbiter_addons.htm

Anyone working on the Ares V to launch it?


Offline imfan

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Re: "Direct" Alternative
« Reply #14 on: 09/01/2006 10:34 PM »
there is ARES V by uwrumpe somewhere. but not sure if it can lift anything else than EDS+LSAM. like this report too. its been some time I read it last time, but seeing your model, there is probably time to read again. nice work

Offline Zachstar

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RE: "Direct" Alternative
« Reply #15 on: 09/02/2006 03:11 AM »
Quote
simcosmos - 1/9/2006  11:45 AM

Quote
kraisee - 1/9/2006  1:24 AM

Yes, I don't believe "perfection" is achievable in the modern climate of economics and politics.

But I think "effective" is possible, and I consider Ares-I and V to be "effective" in their roles.

"Direct" is a better solution still, and continues to fulfill all of the political objectives too IMNSHO. ;)

Ross.

At very least, *Direct* should provide a funny Orbiter addon to play with ;)

António

Woah SimC that is one beautiful rocket!!

I hope you are backing up these like what 20 different models now? Sounds like ALIENS is on the backburner again eh? Keep up the good work!

Offline simcosmos

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RE: "Direct" Alternative
« Reply #16 on: 09/04/2006 06:02 PM »
Hello all,

With a small delay but here go a few answers:


Quote
braddock - 1/9/2006  5:58 PM

Shesh, you've already modeled it?

Hehe braddock: making 3D models about launchers isn't usually too much complicated! The basic shapes are just cylinders or cones with a few holes here and there and I prefer to transfer some of the detail to the textures: this saves modelling time, brings the ability to radically change the visuals with just one simple texture update and increases FPS if the objective is to run the model in a simulator.

Making models for some spacecraft / launch support items might be equally easy: it all depends of how much details we wish to include and how we do the 3D / texture work.


In addition, a few of the Direct launcher components already existed due to the visual / performance update work going on with my NASA VSE SC addon. It was kind of easy - and quick -  to adapt things out for Direct purposes; examples:

a) the ET core's texture has been made having as source the new texture for my conceptual Ares I variant

b) the 4 segment SRB were "recovered" from my older archives and updated for Direct utilization (from some time now that I was just using 5 seg. SRB), etc.


The Orbiter physical implementation should also be somehow quick given that the numbers have STS as starting point (equal to say that are more or less *directly* applied) and, just to give another example, I have also studied the 4 seg. SRB thrust curve in the past.

All that and the fact that this is a smaller project and that it will all be implemented with Vinka's generic dlls (where the masses, "fuel", payload, performance data, etc are quickly implemented in a INI file that everyone can read with notepad) is helping for the quick progress.






Quote
AndyMc - 1/9/2006  8:45 PM

Great stuff António. If only the real ones came as fast! How long until you release some of these 'toys'  ;)


Thanks Andy: you also have nice work being done there ;)

The NASA_DirectSDLV will be a separated addon, with custom directory structure. It should be released much sooner than NASA VSE SC v2.0.

Now... How soon is "much sooner"?

Hummm, I do not like to write about release dates but... I'm trying to upload *something* within some days or a couple of weeks. The amount of direct 'toys' that will be available in such first addon version will depend of real life constraints (running out of free time these days) but, at very least, the interested orbinauts and nasaspaceflight readers will probably be able to play with the Direct CLV (and perhaps with the cargo variant). Components such as custom launch pad, EDS, lunar mission are not certain for the first release, yet (they require extra work)


Quote
AndyMc - 1/9/2006  8:45 PM
I've been a bit busy with a few of my own, based on NASA's DRM - http://gltrs.grc.nasa.gov/reports/2002/TM-1998-208834-REV1.pdf

Some more details of the add-on: http://www.aovi93.dsl.pipex.com/my_orbiter_addons.htm

Anyone working on the Ares V to launch it?


Regarding Ares V: another big side objective of Direct related work is to update the visuals of my planned heavy lifter versions for NASA VSE SC.

This means that:


  • Direct's engine pod will be rotated 45 degrees and will have 2 extra SSME.


  • Direct's core 3D model will be stretched and that the texture dimensions will be adjusted and reapplied to the new core.


  • The new updated parts of Direct's 4 segment SRB will be applied to the 5 segment SRB (already done).



Regarding the EDS, I will still need to make calculations but you can more or less see what I'm aiming for in this old preview:
http://www.flickr.com/photos/simcosmos/180666631/

Direct's EDS still needs to be modelled (using my updated J-2X): it might also later be used as a base to build other NASA VSE SC EDS although, for that my other addon, the basic EDS will probably be ~10m diameter.  

Bottom line: Andy, if you wish one heavy lifter more like the one in ESAS report  (see first variant in the above flickr link) I might do a custom job for your needs (like did for Mars For Less AresI preview - now outdated, btw) using the Direct meshes and textures to update NASA VSE SC heavy lifter's stuff (such update already started).  

Note: it is not in my plans to make a 10m diameter core and use core engines other than SSME derived hardware. If interested, maybe the best is to email me so that we can talk a little about the heavy lifter configuration you wish (beyond the 8.4m diameter / taller SSME powered ET core, you might have options for EDS, fairings and boosters)

If wanting the current (real life) Ares V design: I would be able to do it but, because it would be a different path than what I'm doing now, it would require extra time to research info, etc (I would prefer to spend the time with other projects instead). This to say that I can do it but would not be an higher priority.






Quote
Zachstar - 2/9/2006  3:58 AM

Woah SimC that is one beautiful rocket!!

I hope you are backing up these like what 20 different models now? Sounds like ALIENS is on the backburner again eh? Keep up the good work!

Thanks.

I still work in other projects (very slowly) but yes, my priorities have been more around NASA VSE SC, Mars-Oz and, most recently, these quick Direct 'toys' :)

All the three are somehow inter-linked in some aspects and have potential real life applications: that is why the Science Fiction addons are in the "backburner" from some time now (but not abandoned!) and also why, in part, my site is kind of needing updates (contents, forum still oflline, etc), except for the LivePics or my flickr address, where a few image updates are uploaded with some frequency.


To end this already loooong post: thanks to Ross for the interesting emails about Direct!

Work in progress ;)

António
my pics @ flickr

Offline kraisee

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RE: "Direct" Alternative
« Reply #17 on: 09/05/2006 02:02 AM »
Quote
simcosmos - 4/9/2006  1:49 PM

To end this already loooong post: thanks to Ross for the interesting emails about Direct!

António, you're the one doing me the favour!   My thanks to you for all the hard work you've put in on this already, and I can't wait to see the final results of your labours fly in Orbiter!

Thank-you.

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #18 on: 09/05/2006 07:29 AM »
Also posting this here.
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Online mike robel

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RE: "Direct" Alternative
« Reply #19 on: 09/06/2006 03:54 AM »
Ross,

I guess I forgot:  3 or 4 SSMEs in the core stage?

Why an ATV in your CEV/ATV launch diagram?  Why not just a cargo module that the CEV would deliver (or other self-contained space station module)?

I like the idea, it seems to have minimum change.  Agree with Jim that its a little overkill in terms of capacity for the CEV only, but we could orbit some whomping big cargo modules in additon to crew rotations, as well as have high capacity boosters for future projects.

Mike

Offline simcosmos

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RE: "Direct" Alternative
« Reply #20 on: 09/06/2006 12:33 PM »
Hello Mike

I guess than can answer and Ross will correct me as needed ;)

Quote
mike robel - 6/9/2006  4:41 AM
Ross,

I guess I forgot:  3 or 4 SSMEs in the core stage?

3 SSME (and later modified - expendable - 3 SSME or other equivalent thrust / ISP engine configuration) for the basic Direct launcher variants (ET core with equivalent STS propellants quantity and, at each side,  4 segment SRB)

5 engines whenever it would be time to increase the ET propellants capacity, 5 segment SRB, etc in order to have something more like Ares V (but still with STS ET diameter).

Quote
mike robel - 6/9/2006  4:41 AM

Why an ATV in your CEV/ATV launch diagram?  Why not just a cargo module that the CEV would deliver (or other self-contained space station module)?

I believe that the ATV in the picture is just an example, but one thing is more or less certain (for basic Direct CLV variants): the payload under the CEV would need at least some kind of RCS mini-module or even its own propulsion module (if a station module, it could be something like Russian ones) given that the CEV + payload would be injected into a sub-orbital trajectory (for safe disposal of the ET core, like in STS).

If the payload has some RCS capability, it would then be able to keep a given stable attitude and allow the CEV to dock with it and act as the payload's main propulsion. However, in order to avoid such delicate operation before the circularisation burn, perhaps it would be better if the payload had a powerful enough RCS module or even its own small expendable tug (at least capable of making it reach a stable low orbit) or if that payload and its tug were somehow connected to the CEV's SM bottom.

It is in times like this that a Biconic CEV (or capsule with hole in the heatshield) would be very handy, hehe but we can find solutions for the current CEV configuration + basic Direct + extra payload. Anyway: there are some options / talks about the topic being considered by Ross and me in our emails ;)

Meanwhile, I have uploaded a new image in my LivePics page (later to be moved to the flickr photo set) as well uploaded past development images in the flickr url. For the interested, just click in the thumbnail or in the links that are in my forum's signature.

Work in progress... The first Orbiter simulator implementation should happen *soon*: the flight tests should then provide a few nice images and, if having time, will perhaps also do a clumsy demo - read development - video (not 100% sure yet)

António
my pics @ flickr

Offline Norm Hartnett

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RE: "Direct" Alternative
« Reply #21 on: 09/06/2006 06:10 PM »
Quote
kraisee - 5/9/2006  2:16 AM

Also posting this here.

Gads, that sure is a good looking vehicle. To bad NASA isn't going to develop it.

I don't think I ever saw a full costing on this. Are you doing one or did I miss it?
“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 kraisee

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RE: "Direct" Alternative
« Reply #22 on: 09/06/2006 10:01 PM »
Quote
mike robel - 5/9/2006  11:41 PM

Ross,

I guess I forgot:  3 or 4 SSMEs in the core stage?

Mike, António already replied, but I'll phrase it my own way too :)

The Phase 1 "Direct" Shuttle Derivative, would utilise 3 standard SSME's, and the exact same tank capacities used today.   It would basically do the same job as STS does right now, taking ~142mT of hardware up the hill on every flight.   The difference though, is the proportion of that mass which is useful payload.   The configuration change allows you to trade Orbiter mass for payload.   "Direct" launches 73.9mT of useful hardware to LEO instead of just 16mT using STS.

The intention is to replace the main engines with a cheaper alternative as soon as it can be developed.   Either 3 x RS-25e (no requirement for air-start, just chep production) or 2 x Hi-Isp (450s vac or better) RS-68 derivative can be utilised.   Rocketdyne/P&W would have to perform trades to confirm which is the best cost option to persue, and that's what we go for ultimately.


Quote
Why an ATV in your CEV/ATV launch diagram?  Why not just a cargo module that the CEV would deliver (or other self-contained space station module)?

I used it as a demonstration of utilising the extra capacity of the Direct.   It's only really a suggestion, but it does offer a number of advantages:   ATV is almost ready to fly right now and it requires no additional development money to be spent at all.   It neatly fits inside the SLA, and would be more than capable enough to provide cargo delivery at the same time as CEV flights.   Other options are possible, but they all require development $$$.


Quote
I like the idea, it seems to have minimum change.  Agree with Jim that its a little overkill in terms of capacity for the CEV only, but we could orbit some whomping big cargo modules in additon to crew rotations, as well as have high capacity boosters for future projects.

Exactly.

Ares-I can't offer any other capabilities other than CEV launches.   It isn't capable of doing anything else.

Direct can open up a lot of options which Ares-I can't, and saves a lot of time & money in the process.

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #23 on: 09/06/2006 10:07 PM »
Quote
Norm Hartnett - 6/9/2006  1:57 PM

Quote
kraisee - 5/9/2006  2:16 AM

Also posting this here.

Gads, that sure is a good looking vehicle. To bad NASA isn't going to develop it.

I'm putting together a proposal.   NASA has not done much yet on the Ares progrm which isn't helpful to Direct too.   It would not actually take a radical course correction to go this path.   With the right argument (saving $8Bn development and $2Bn per year operational), I think it could gather support.


Quote
I don't think I ever saw a full costing on this. Are you doing one or did I miss it?

Dang, sorry Norm.   I posted one on another thread, but forgot to include it here.   Let me amend that...

Ross.
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Offline rsp1202

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RE: "Direct" Alternative
« Reply #24 on: 09/07/2006 12:34 AM »
I agree; the crew launcher (Ares 1B?) has changed from a sow's ear into a silk purse. (Though I don't know why LM added the little button nose to the LES/boost protective cover.) Now, suggest a clever way of docking the CEV/LSAM to the EDS on the cargo hauler (Ares 1C?), and I'm sold. I also must have missed something: you're saving the Ares V for Mars?

Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #25 on: 09/07/2006 12:50 AM »
You dock the CEV to the LSAM. Your pilot gets into the LSAM and docks it to the EDS using some nifty adapters on the landing pads of the LSAM. Seems simple and "Direct" to me. :)

Thanks Ross you did publish some graphs in this thread on page 1.
I was looking for something more like a spreadsheet with a bit more detail.
“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 rsp1202

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Re: "Direct" Alternative
« Reply #26 on: 09/07/2006 02:22 PM »
Okay, at least it's a concept. Thanks.

But it's not that simple if you have to take time to move crew into the LSAM, power up its systems, and fly backwards with a big honkin' package stuck to your nose while making delicate docking maneuvers. Adapter also adds a degree of mechanical complexity, but whether that's marginal or not, I don't know. Then what; power everything down in the LSAM for coast phase, then power up again reaching Moon orbit? Mission timeline is effected, too; how long do you want to linger in Earth orbit doing things before TLI. There's also the change of philosophy, not using the CEV to control major maneuvers.

The two-launch Direct method is elegant in many ways, and perhaps these things by themselves are not that big a deal. I'm easy to convince, NASA maybe not so much.

Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #27 on: 09/07/2006 04:33 PM »
Yeah that was a simplistic answer and I'm no Rocket Scientist but I'll babble anyway.

Actually I would be more concerned about getting the CEV and LSAM mated than about getting them docked to the EDS. If the CEV initial orbit criteria are as they are now you would have a very limited amount of time to get mated and have the SM (presumably much bigger) get your short stack into a safe orbit or alternatively if your initial orbit criteria was defined by a need to safely dispose of the ET you would still have a limited mating time. A failure to launch the EDS would leave you the unpleasant choice of dumping the LSAM into the atmosphere.
Assuming all that happened you wouldn't be looking at "fly backwards with a big honkin' package stuck to your nose while making delicate docking maneuvers" Remember the LSAM is designed to land on it's feet. A better way of putting it would be "landing with a big honkin' package stuck to the top of your head while making delicate docking maneuvers" basically the LSAM is designed to fly that direction.
If NASA can have a truss screw itself...
to the ISS then I am sure there are any number of options for getting a hard dock to the EDS. Since at least one design for the LSAM has large solar arrays, power might not be an issue plus the Direct design may have enough margin for a fairly large SM able to supply consumables for both modules. All this is just me gassing of course.
“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 rsp1202

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Re: "Direct" Alternative
« Reply #28 on: 09/07/2006 04:48 PM »
No, good show. The devil's in the details, and this little one is critical to Direct operations. There are bound to be more. I was concerned about control laws for handling the stack, line of sight issues for the pilots, increased workloads, power consumption -- a whole bunch of conditions spiraling out from this one operation.

I'd like to see these things fly, but not if it's used as a political/cost excuse for cancelling Ares V down the road.

Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #29 on: 09/07/2006 05:03 PM »
Another thing that just popped into my mind. The Apollo capsule docking to the LEM/TLI stack (or the CEV docking to the LSAM/EDS) was a small mass bumping into a big mass. With Direct you have two dockings. A small mass bumping into a slightly bigger mass and then two more almost equal masses bumping into each other. Elastic collisions with near equal masses do not lend themselves to hard docks.
“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 HailColumbia

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Re: "Direct" Alternative
« Reply #30 on: 09/07/2006 05:36 PM »
Quote
Norm Hartnett - 7/9/2006  12:20 PM

If the CEV initial orbit criteria are as they are now you would have a very limited amount of time to get mated and have the SM (presumably much bigger) get your short stack into a safe orbit


What about using the LSAM to perform the burn to a safe orbit while still in the adapter? You would have to redesign the adapter probably, but, as its an imaginary adapter anyway, thats not a big deal.  (and of course you would lose precious decent propellent)
-Steve

Offline yinzer

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Re: "Direct" Alternative
« Reply #31 on: 09/07/2006 06:12 PM »
Quote
Norm Hartnett - 7/9/2006  9:50 AM

Another thing that just popped into my mind. The Apollo capsule docking to the LEM/TLI stack (or the CEV docking to the LSAM/EDS) was a small mass bumping into a big mass. With Direct you have two dockings. A small mass bumping into a slightly bigger mass and then two more almost equal masses bumping into each other. Elastic collisions with near equal masses do not lend themselves to hard docks.

Sure they do.  The ISS is rapidly approaching the weight of the Shuttle Orbiter, and they dock just fine.
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Offline yinzer

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Re: "Direct" Alternative
« Reply #32 on: 09/07/2006 06:26 PM »
And yeah, this is one of the problems with using the "Direct" launcher to carry large amounts of cargo to ISS.  Shuttle uses the OMS engines to do a two-burn ascent to LEO.  This requires less delta-V overall, and when one is carrying along a lot of non-payload weight, that's important.  Also, when the upper stage weighs 30-70 tons, you need to be much more careful about where it lands, which suborbital injection helps with.

But you need an engine restart to make it work and RCS for the between-burn coast period.  If you're using SSME for the ascent, that means you need separate circularization engines.  Not an insoluble problem, but if your launch vehicle is cheaper because you ditch all the Orbiter costs, except for the aft fuselage, and except for the GPCs, and except for the OMS/RCS pods... you can see where this leads.
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Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #33 on: 09/07/2006 06:41 PM »
Quote
yinzer - 7/9/2006  12:59 PM

Quote
Norm Hartnett - 7/9/2006  9:50 AM

Another thing that just popped into my mind. The Apollo capsule docking to the LEM/TLI stack (or the CEV docking to the LSAM/EDS) was a small mass bumping into a big mass. With Direct you have two dockings. A small mass bumping into a slightly bigger mass and then two more almost equal masses bumping into each other. Elastic collisions with near equal masses do not lend themselves to hard docks.

Sure they do.  The ISS is rapidly approaching the weight of the Shuttle Orbiter, and they dock just fine.

Oh good needn't worry about that then.
“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 kraisee

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Re: "Direct" Alternative
« Reply #34 on: 09/07/2006 08:27 PM »
Quote
HailColumbia - 7/9/2006  1:23 PM

What about using the LSAM to perform the burn to a safe orbit while still in the adapter? You would have to redesign the adapter probably, but, as its an imaginary adapter anyway, thats not a big deal.  (and of course you would lose precious decent propellent)

Hail, that is *precisely* the mode I have been assuming, and which sim is going to model in Orbiter for this.

And I'm toying with an idea of "topping-off" the LSAM's Decent tanks with LOX from the EDS after docking.   It's not necessary I don't think, but offers one growth option which would increase performance in the future.

As it is though, Direct can place about 13mT extra in LEO (IMLEO) at the start of the mission compared to the Ares-I and V together, so this is not necessary.

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #35 on: 09/07/2006 08:48 PM »
Quote
rsp1202 - 6/9/2006  8:21 PM

I agree; the crew launcher (Ares 1B?) has changed from a sow's ear into a silk purse. (Though I don't know why LM added the little button nose to the LES/boost protective cover.) Now, suggest a clever way of docking the CEV/LSAM to the EDS on the cargo hauler (Ares 1C?), and I'm sold. I also must have missed something: you're saving the Ares V for Mars?

Rsp,
My approach to this extra docking maneuver would be to keep the crew aboard the CEV - so they are permanently in their lifeboat, just in case.   Control the docking to the EDS from there IMHO.

There will be full suite of cameras and landing radar on the LSAM for Lunar approach anyway, so these can be used for this docking operation.   The crew won't be able to see the EDS during this approach because it will be obscured by the descent stage anyway, so it must be done by camera and instruments.   Further, the LSAM is being designed to perform completely autonomous Lunar landings, so the systems will already be set-up to be remote-controlled anyhow.   This should thus not impact the mass allocation of the LSAM in any way.

Here's a rudimentary drawing showing the basic approach...

I have a design for a simple mechanical release system (not pyro) which "lets go" of the entire cradle holding the LSAM in the SLA through it's launch.   The SLA separates from the core, with the LSAM still inside, and the CEV remaining on top.   LSAM then performs the circ. burn and the remaining section of SLA are then discarded.   The CEV then transitions and docks.   This approach has the benefit of fully testing the LSAM's engines and knowing they work even before the TLI occurs.

As I just mentioned, after docking with the EDS, the LSAM's descent stage tanks could be topped off by the EDS if additional performance is required, but the "Direct" approach already launches a larger LSAM and more propellant than Ares does, so this isn't actually needed.


Ares-V actually becomes unnecessary for Mars.   It sure would be nice, but if it's cancelled, the first launch vehicle you built, the CLV, is still capable enough still launch Mars missions in just five 90mT launches, placing 450mT in LEO!   Four launches of Ares-V also place about 450mT in LEO, but you still need to launch the crew on a fifth launch - so there is no real benefit to that approach.

*IF* the money still exists in 12 years time to grow the "Direct" into a really big launcher, you can easily make the original 27ft diameter ESAS CaLV design, which gives the same performance as Ares-V.  But the CaLV is taken out of the critical path, and even if it gets cancelled we can still go explore.   With just Ares-I, if Ares-V is cancelled we ain't going nowhere at all.

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #36 on: 09/07/2006 08:53 PM »
And Norm,
I'm continuing to develop the finite details of the cost structure.

I've got this updated comparison which includes the EDS costs in the totals for both Ares and Direct approaches.

I think you'll all agree this is quite an eye-opener.

Ross.
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Offline yinzer

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Re: "Direct" Alternative
« Reply #37 on: 09/07/2006 09:49 PM »
The ESAS report claimed that a 4-seg RSRB w/ 3xSSME core stage would require 3 launches to do the lunar mission - this is the vehicle that you are suggesting.  How do you enable the two-launch solution?

And if a 70-ish ton launch vehicle can do a two-launch solution, why not use the Atlas Phase 2, which can Lockheed says can lift 73 tons in a 3-body configuration while still being able to carry the CEV to ISS in a single-stick configuration, and being much more useful to the commercial and military launch markets by bringing economies of scale to Atlas production?

Round and round we go, I suppose.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #38 on: 09/07/2006 10:30 PM »
Yinzer - yes, the ESAS did exactly that.   But it did not factor in any EDS.

With the use of the EDS during the latter part of the ascent phase, like Ares-V does, you boost NET performance by 15mT and you get the 19mT of EDS in orbit in addition.   Two launches places 183mT in LEO at the start of the mission, which is 13mT more than Ares-I and Ares-V will launch together.

That firmly places this solution into the 2-launch category.

And I'm sorry, while "1.5 launch" sounds less, it isn't.   Count the number of launch vehciles they use...   Unless my math teacher "learned me bad"; 1 plus 1 still equals 2, not 1.5...

And frankly, running two launch vehicle operations instead of just one will cost a LOT more, not less.

And yes, Atlas Phase 2-Heavy (3 core) could also do this.   If NASA could get around the political crap-shoot which would follow all those job losses.   I could easily support that solution if the politico's could.

Ross.
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Offline rsp1202

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Re: "Direct" Alternative
« Reply #39 on: 09/07/2006 10:55 PM »
Re: Phase 2. It's also risky to trust future viability of offshore supply lines. Producing RD-180's here in the States should be emphasized, unless RS-84 development is pushed.

And Ross, I agree the CEV should control docking; using IFR and auto systems is mandatory, especially if the LSAM turns out to be one of the horizontal-design concepts rather than vertical as envisioned in ESAS.

Online mike robel

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RE: "Direct" Alternative
« Reply #40 on: 09/08/2006 01:19 AM »
Ross,

As you develop your alternatives, I ask you consider "Direct" approaches to Mars.  Throw the Mars Habitation Module directly to the surface of Mars so it lands  and is there before the astronauts.   Assemble as little in LEO as possible, increases reliability, decreases risk, etc, etc.

Mike

Offline zinfab

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Re: "Direct" Alternative
« Reply #41 on: 09/08/2006 01:56 AM »
Would LockMart lunar lander (SUV version 1) would fit in this approach? I really want that lander and this launch vehicle.

Since I'm dreaming anyway... Besides, we'll have all that extra cash from the single LV operations costs.

Offline rumble

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Re: "Direct" Alternative
« Reply #42 on: 09/08/2006 02:30 AM »
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zinfab - 7/9/2006  8:43 PM

Would LockMart lunar lander (SUV version 1) would fit in this approach? I really want that lander and this launch vehicle.
The LockMart "dual-axis thrust" lander?  Interesting indeed.  Its primary thrust unit (RL-10) would work well for the final kick to earth orbit.  And in this configuration, the CEV/SM would remain on top of the LSAM, sans shroud, but with an additional frame structure that would allow the SM to sit atop the LSAM.

In this config, the CEV could dock nose-first with the EDS, with the LSAM still attached to the frame structure.

So we use up some of the LSAM's fuel for EOI?  The LockMart SUV1 version's propellants would be the "cheapest" (weight-wise) to use up.  Cheaper than the SM's hypergolic.

Why isn't it that simple...  (I've got to be missing something)

Offline kraisee

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RE: "Direct" Alternative
« Reply #43 on: 09/08/2006 04:28 AM »
Mike, the way I figure it, 90mT launched per shot should be large enough to make almost any individual modules you're ever going to need for any Mars mission, be it combined into one spacecraft or multiple.

I tend to agree that having a working and checked-out Hab and supplies on the Martian surface before committing the crew to a mission is likely to be very sensible, but other good plans exist too and the final mission method has yet to be settled upon at this stage.

Ultimately though, I believe "Direct" can do virtually anything Ares-I & V can do, and do it cheaper.

Either approach, you need to launch 450mT from the surface of the Earth at a minimum to start any Mars-bound mission.   Even just to send an unmanned Hab, you're talking about at least 350mT IMLEO.

350mT requires three Ares-V's and one Ares-I (4 launches in total), or 4 "Direct" launches.

450mT requires either 5 Directs or 4 Ares-V's and one Ares-I vehicles.

Even 540mT can be launched on 6 of either type.


If you want 630mT IMLEO, you save one Ares-V launch compared with "Direct", at a total NET saving of just $40m.   However your operations cost for the two different vehicles is still $1,120m per year more than Direct!   You do not get *any* NET operational savings using Ares vehicles unless you reach a launch-rate of TWENTY-EIGHT Ares-V's every single year!   And I think we'd all agree that's never going to happen.

"Direct" is significantly cheaper below that flight rate - and that does not even take into account the $20Bn or-so which you saved during the development cycle by choosing to only develop one vehicle instead of two - and that $20Bn is worth between 80 (w/ EDS) and 133 (w/out EDS) extra "Direct" launches right there.

Ross.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #44 on: 09/08/2006 04:38 AM »
Quote
rsp1202 - 7/9/2006  6:42 PM

Re: Phase 2. It's also risky to trust future viability of offshore supply lines. Producing RD-180's here in the States should be emphasized, unless RS-84 development is pushed.

And Ross, I agree the CEV should control docking; using IFR and auto systems is mandatory, especially if the LSAM turns out to be one of the horizontal-design concepts rather than vertical as envisioned in ESAS.

I don't *think* the RD-180 supply is an issue.   Kayla indicated that P&W did have a license to build RD-180's here in the US exclusive of the Russian manufacturing facilities.   The question does however remain whether P&W has the rights to alter the engine's specs independantly of the Russians - and that will be vital to man-rate the engine to NASA's preference.   I suspect the answer to that is yes - but there has not yet been any way to confirm that suspision.

And yeah, these guys are rocket scientists - they can figure out a way to do almost anything, heck, rumour has it these guys can even take people to the moon... ;)

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #45 on: 09/08/2006 05:59 AM »
Here are two different mission models to demonstrate a couple of the wide range of potential options which are possible.

There are other variants of these, and some completely different approaches too, but these simply demonstrate some of the available options.

A detailed engineering analysis is needed to work out which of the various options offers the best possible performance - and that analysis would be the mechanism for choosing the final method to use.

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #46 on: 09/08/2006 06:10 AM »
And here are some more of António's wonderful 3D renderings of the payload options for "Direct".

From left to right are:

CEV + 45,000kg 'ballast' module in empty SLA.
CEV + 22,000kg ATV ISS cargo delivery module
CEV + 45,000kg LSAM
LM-style CEV + 45,000kg LSAM
8.4m diameter, 16m long cylindrical, 24m long Center-Line generic Payload Shroud.

These have actually already been changed, but I thought you'd like to see the "work in progress"...

Thanks António!!!

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #47 on: 09/08/2006 06:13 AM »
And here are new adjusted costings graphs, with the $3Bn development cost for the 3-seg SRB's moved to the CLV from the CaLV, and a few tweaks to 'accurize' the Direct's development budget too...

R.

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Offline rsp1202

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RE: "Direct" Alternative
« Reply #48 on: 09/08/2006 01:42 PM »
Excellent graphics increase the demand for more. How about putting the Lockheed lunar lander under the shroud.

Poor Antonio, working under sweatshop conditions.

Offline simcosmos

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RE: "Direct" Alternative
« Reply #49 on: 09/08/2006 09:12 PM »
Quote
rsp1202 - 8/9/2006  2:29 PM

Excellent graphics increase the demand for more. How about putting the Lockheed lunar lander under the shroud.

Poor Antonio, working under sweatshop conditions.

haha :)

The idea of making the LM lander already crossed my mind but do not have time now to make that cool lander: I'm trying to focus in the final preparations required to start the conversion of Direct launchers and textures to the formats used by Orbiter but still have a few tweaks and verifications to make in the 3D editor before doing that (might leave some of those remaining tweaks for a later version and just close the eyes to the things that would need to be improved).

As for more eye-candy aka image updates about the ongoing development: when possible I will do them but my free time is really starting to be very limited and other projects are also calling my attention. So, do not strange (or worry about, hehe) with the lack of Direct  *demo images*: the work is continuing just fine in the backstage and I'm obviously anxious about placing these 'toys' inside Orbiter Simulator to do some flight tests (will probably transmit a few of those development sessions in my LivePics page, when the right moment arrives)

Work in progress, step by step :)

António

Note: just to give credits where credits are due, the ATV and the LSAM + big CEV displayed in the Direct_SDLV_20060807_Payloads-render.jpg were note made by me. Unless I'm messing up the correct references, the ATV is from Brad Hodges ( www.simnasa.org ) and the LSAM + big CEV are from Franz Berner aka francisdrake (from his ESAS CEV addon, that I will try to integrate with my Direct models). ATV, ESAS CEV and LSAM were imported to the 3D editor – with no materials info – just to be used as test articles. I'm the author of all the rest (Direct launchers models, CEV DAC2 model, etc).
my pics @ flickr

Offline kraisee

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RE: "Direct" Alternative
« Reply #50 on: 09/08/2006 09:40 PM »
Here are the latest cost table updates.

I have added the expected first launch dates for the first manned CEV, and the "Apollo 18" manned lunar mission.

I have then re-worked the budget for Direct to expedite both.   Staying within the budget limits for the current Ares budget, "Direct" can launch the CEV a whole year earlier, and can launch the Lunar mission 2 whole years early!

Enjoy...

Ross.

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Offline Zachstar

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RE: "Direct" Alternative
« Reply #51 on: 09/09/2006 06:16 AM »
Amazing work!!!

Just shows what good communication and getting goodwith SimC can get you :P

The more I look at this, the better it seems to be. The is the REAL safe...simple...soon that can be made. The current plan NASA is using is rather poor (Ok very poor) compared to this.

Thanks for the Continued efforts!!

Offline lmike

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RE: "Direct" Alternative
« Reply #52 on: 09/09/2006 12:56 PM »
Low granularity.  Too few launches.  Brittle (one launch fails the fleet is grounded forever) approach.

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RE: "Direct" Alternative
« Reply #53 on: 09/09/2006 01:02 PM »
practical, reduced complexity, heavy lifting, direct application for mars missions, a sound approach that would deserve to succeed

Offline lmike

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RE: "Direct" Alternative
« Reply #54 on: 09/09/2006 01:17 PM »
Quote
mong' - 9/9/2006  5:49 AM

practical, reduced complexity, heavy lifting, direct application for mars missions, a sound approach that would deserve to succeed

Reduced complexity? No.  You have to design the whole Mars bound spacecraft to fit into a launch.  Heavy lifting?  Nope.  500mt to LEO in one go would be heavy lift.  This is not going to work for Mars.  Therefore, it's not practical.  (edit: better to admit the failure and re-calibrate the architecture)

Offline rumble

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RE: "Direct" Alternative
« Reply #55 on: 09/09/2006 02:57 PM »
Quote
lmike - 9/9/2006  8:04 AM

Quote
mong' - 9/9/2006  5:49 AM

practical, reduced complexity, heavy lifting, direct application for mars missions, a sound approach that would deserve to succeed

Reduced complexity? No.  You have to design the whole Mars bound spacecraft to fit into a launch.  Heavy lifting?  Nope.  500mt to LEO in one go would be heavy lift.  This is not going to work for Mars.  Therefore, it's not practical.  (edit: better to admit the failure and re-calibrate the architecture)
I see a Mars crew compartments being several modules, so multiple launches shouldn't be too much of a problem.

I think ultimately, we need to see "Direct" or Stick/CaLV as just an interim architecture, and as such, I think it works.  I don't expect we'll be content using this VSE architecture for the next 50 or more years, but as a step, it's good.  Otherwise, I think you're correct.  At some point in the future (if we are to be space-faring beings), we'll need a vehicle that can either lift some REALLY BIG things into orbit, OR, a vehicle that's really inexpensive to operate combined with an increased ability to BUILD things in orbit.

You also mentioned that direct could be more easily grounded...  I'm not sure that's necessarily true.  If either CLV or CaLV have a problem, the mission is effectively grounded, regardless whether the issue affects only one of the two rockets.  Flying one without the other doesn't deliver a manned mission beyond LEO.  But on the other hand, if an SRB has an issue, doesn't that ground both rockets?  If a J-2x has a problem, the same thing.

Offline lmike

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RE: "Direct" Alternative
« Reply #56 on: 09/09/2006 03:05 PM »
Just a (admittedly pedantic) note, there is no VSE architecture.  The VSE is a (nebulous) goal as stated in a speech by Bush Jr.  The ESAS is a proposed architecture to fulfill the goal.  The argument is whether the ESAS does fulfill the VSE, or just some pockets.

Offline rumble

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Re: "Direct" Alternative
« Reply #57 on: 09/09/2006 03:48 PM »
heh heh...  ok.  My bad.  I keep trying to figure out ways to abbreviate CLV/CaLV (specifically stick + rs-68/SRB CaLV), as opposed to any of the proposed alternatives for accomplishing the CLV and CaLV tasks.  Thanks for the correction.

Another observation:  using the word "pedantic" automatically makes one guilty of being so.  :)   (that's always cracked me up)

M.

Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #58 on: 09/09/2006 04:25 PM »
Hey Ross, thanks, those numbers look really really good.

That LOC number would be a problem wouldn't it? As I understand it the Astronauts Office was a big factor in selecting the Stick.  

Edit: Opps appears my browser didn't pickup an entire page, never mind.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #59 on: 09/09/2006 04:39 PM »
Quote
lmike - 9/9/2006  8:43 AM

Low granularity.  Too few launches.  Brittle (one launch fails the fleet is grounded forever) approach.

I might even agree with that.   But with cost savings in the ball-park of $2Bn every year compared to Ares - I wonder if LM couldn't use that to also start work on a second-tier Atlas Phase-2 (AP2) LV system as well?   A 3-core AP2 can launch about the same as this, so all you'd need is a generic payload adapter...

Two systems, one SDLV, one EELV, would provide great backup for each other.

Ross.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #60 on: 09/09/2006 05:14 PM »
Norm, the LOC is still plenty above the 1:1000 which was the target NASA had for the new system, independant of the Astro Corps.

ESAS had the best EELV CLV (man-rated Delta-IV Heavy w/ new upper) at 1:1100, and it got a yellow mark.   The worst of the SDLV's was the Stick with 4 LR-85's @ 1:1429, and that was marked green.

"Direct" is between those, although much closer to the first.   I'd say it's probably acceptable.   Like all of the solutions, it's certainly a magnitude safer than STS - which is the main issue.   I think there's a lot to be said about flying a lot of the exact same hardware we're already very familiar with, with the minimum possible number of changes.   We know this hardware works well.   If we could only change the configuration into something better...

As for the numbers, yes, you're absolutely right.   Well spotted.   Attached is an amended table, and I've included the correction and your suggested additions.   Thanks.

I have also taken the liberty of costing the full-up price of a single hypothetical 500mT-minumin IMLEO Mars-mission too.   And I'm assuming that single mission absorbs all of NASA's Operations costs for a complete year in both cases.

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #61 on: 09/09/2006 07:31 PM »
Quote
lmike - 9/9/2006  9:04 AM

Quote
mong' - 9/9/2006  5:49 AM

practical, reduced complexity, heavy lifting, direct application for mars missions, a sound approach that would deserve to succeed

Reduced complexity? No.  You have to design the whole Mars bound spacecraft to fit into a launch.  Heavy lifting?  Nope.  500mt to LEO in one go would be heavy lift.  This is not going to work for Mars.  Therefore, it's not practical.  (edit: better to admit the failure and re-calibrate the architecture)

Mike, sorry, you seem to have the wrong end of the stick (no pun intended!) :)

Believe me, I've not been trying to promote any single-launch solution to Mars.   "Direct" is not going to be a Nova-class booster, but then again none of the realistic solutions we have seen were ever going to be (Ares, Direct, EELV derivatives etc).   I'd love that sort of system, but it's not practical - yet.


What I am trying to indicate is that Direct is considerably cheaper than Ares for launching a Mars mission.

And the slightly lower max payload of 90mT compared to Ares-V's limit of 123mT (plus EDS in both cases) is not going to prove to be much in the way of a hinderance.   There simply are no modules being planned for any of the Mars mission concepts of recent years which can't be built in 90mT "chunks" instead of 123mT "chunks".   A 90mT Hab is considerably heavier than SkyLab was, so that is not going to be a limit.   You're going to require multiple propulsion modules on Ares anyway, so while you may need one extra module, it is not a limit of payload mass.   Also, 3 x 90mT individual modules with an engine on each offers more performance than 2 x 123mT modules - approximately 10% more propellant (~24mT) is available.

The only really critical item at this conceptual phase would be the size & mass of the lander you bring with you.   And 90mT is still *far* more than any of the current Mars lander concepts which have been proposed.   Even if it were to somehow prove to be some sort of limiting factor, the ascent stage could be launched on a separate flight, or the entire unit could be launched 'dry' and the propellant be tanked in orbit.   Either approach (or both) allows for vast amounts of growth in the design, far beyond any Mars Lander concept currently conceived of.

The bottom line is that Direct can easily launch all of the same hardware as Ares can, with just a different launch sequence.   There are NO technical hangups to this approach at all.   That means it all comes down to the cost:performance analysis - and that's where Direct takes the clear lead...


Every serious Mars mission is going to mass somewhere in the 450mT to 500mT IMLEO ball-park.   That means that any Mars mission launched with the realistic vehicle alternatives we have (Ares, EELV derivatives or Direct) will have to be modular in concept.    And there is going to have to be some assembly required in Earth Orbit prior to setting off for all of them.

Now, the current Ares-I and Ares-V which NASA are planning to build, can launch 25mT and 123mT respectively to LEO.

This "Direct" concept can launch either 74mT or 90mT at a time, depending solely on whether you fly the EDS or not.   But the critical point is that it does so for *FAR* less money than Ares - and cost saving for using Direct far outweigh's the performance benefit of the larger Ares-V vehicle.


Let me demonstrate with just a hypothetical "500mT mission to Mars":

Ares-I and Ares-V together can launch 517mT in four launches of the big CaLV, and one CLV for the crew, for a total of 5 launches.   Total Fixed & Variable costs for those is $4.22Bn [.9+2.2+.12+(.25x4)]   That equates to $8,162 per Kg to LEO ($3,702 per lb).

Direct can launch 524mT on 6 flights.    Five of which have an EDS upperstage to boost performance.   Total Fixed & Variable cost for those 6 flights is $3.20Bn [1+.9+.15+(.23*5)]   Thats $6,107 per Kg to LEO ($2,770 per lb).


So, for each Mars mission, Direct saves more than $1Bn every time go.

And Direct does not preclude NASA from also building the Ares-V as well.   Direct should cost no more than Ares-I to develop.   If the money is still available after the "CLV" is built, NASA can still build the "CaLV" if it wishes.   But the "CaLV" is no longer in the critical path, because the Direct "CLV" opens up enough capacity to make Lunar and Mars missions possible right from the start.

Ross.
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Offline bad_astra

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Re: "Direct" Alternative
« Reply #62 on: 09/09/2006 08:33 PM »
Stands to reason that Direct could have pretty rapid launch times, with a surplus of RSRB's, much faster then STS, and with the reduced heighth perhaps a little faster then Ares V (the current Ares V "Longfellow" baseline)
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Offline rumble

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Re: "Direct" Alternative
« Reply #63 on: 09/09/2006 08:39 PM »
Ross, you keep using examples of Direct with or without an EDS (74 & 90mT to LEO each).  But they both have the same 1st stage.  Sans EDS, it's basically an SRB assisted SSTO.  With EDS, it's a classic 2-stage rocket.

Since the two versions will have different GLOWs (16mT difference in payload + whatever the EDS is), I assume there will be a fairly dramatic difference in how quickly the two jump off the pad.  What is the T/W ratio of the two at liftoff, and what's the difference between max G-forces for the two vehicles?  Additionally, will they have to fly different ascent profiles because of the T/W difference?  It may not be a significant difference, but I assume you have those numbers handy...

...and you may have published this before and I just missed it...

Offline kraisee

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Re: "Direct" Alternative
« Reply #64 on: 09/09/2006 08:47 PM »
Yes Astra,
It sure wouldn't need the month sitting out at the Pad.   I'd guess a week to ten-days would be required on the Pad.   And as long as the payload is integrated into it's shroud before being delivered to the Transfer Aisle, I see stacking in the VAB taking no longer than STS does today.   So my guess would be 4 or 5 weeks to turn around each flight.   Using two HighBays, two MLP's and both Pads you could realistically achieve 25 flights a year - assuming you had enough payloads to fly!

Of course, funding levels won't ever allow that sort of flight rate, but I'd say that ten per year would be easily feasible, and at that point economies of scale come into play, and the Fixed costs get spread much more thinly so I'd expect at a flight-rate of 10 per year you'd probably reduce the individul flight costs by 25% or so.   But I'm not accounting for economies of scale into any of my figures.

Ross.
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Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #65 on: 09/11/2006 03:54 AM »
I've been pondering what could be done with the extra 49mT on the CEV launch.

One possibility is mission modules consisting of a module SM plus module in various sizes depending on mission:

LEO Lab (various on orbit lifetimes could be contemplated)
LEO Satellite Service mission
GEO Satellite Service mission
Lagrange Libration point Satellite Service mission

That's all that come to mind but I'm sure there must be more.

Edit: Ah another just came to mind perhaps a second unmanned CEV combined with an EDS launch for lunar orbit rescue if a CEV fails in Lunar orbit? 25mT CEV + 25mT CEV still leaves you 24mT for something (oversize SM?)

“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 HailColumbia

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Re: "Direct" Alternative
« Reply #66 on: 09/11/2006 04:10 AM »
could you build a 49T EDS with enough power to do a TLI with just the CEV? (no LSAM)
If you can, you could do missions to near earth objects, that you wouldent nessessarily need an LSAM to land on. I am thinking some rudimentary legs with pitons attached to the CEV itself. This is sort of a hillbilly way of doing things, but seems like it would be doable and cheap.
-Steve

Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #67 on: 09/11/2006 04:13 AM »
Quote
HailColumbia - 10/9/2006  10:57 PM

could you build a 49T EDS with enough power to do a TLI with just the CEV? (no LSAM)
If you can, you could do missions to near earth objects, that you wouldent nessessarily need an LSAM to land on. I am thinking some rudimentary legs with pitons attached to the CEV itself. This is sort of a hillbilly way of doing things, but seems like it would be doable and cheap.

I like that, you could put the legs on the mini EDS for that matter.

If a mini EDS doesn't give you enough deltaV you could use a full blown one and use a mission module plus CEV for NEO landing.
“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 meiza

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Re: "Direct" Alternative
« Reply #68 on: 09/11/2006 01:10 PM »
Wouldn't the more likely alternative for NEO missions be to use the existing LSAM since it already has the life support for the required time and can also provide delta v to the stack? You would then "land" with the CEV attached.

Offline HailColumbia

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Re: "Direct" Alternative
« Reply #69 on: 09/11/2006 01:50 PM »
Well it has to get there first, does the LSAM have enough thurst to perform a TLI (or uh TNEOI or whatever you would call it).  Clearly you are right that if you had an LSAM with you, the mission would be more robust. The "mini eds" mode allows you to do it in one launch.
-Steve

Offline bad_astra

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Re: "Direct" Alternative
« Reply #70 on: 09/11/2006 02:24 PM »
Depends on the NEO. But since the LSAM would already exist and would be good for the operation without too much modification, might as well use it. If territorial claims ever start being made in space, the LSAM would be a handy thing to have.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #71 on: 09/11/2006 02:29 PM »
Rumble,
Yes, the two GLOW's are considerably different, yet the liftoff thrust remains the same.

After some new information, the primary design for Direct has actually changed just recently.

In short, I've switched from the three SSME's to two RS-68 Regen engines instead.   It has roughly the same performance, but the costs are considerably lower, production difficulties are addressed completely, and the reduction in number of engines increases the safety numbers even more.

I'm re-working the simulations still and optimising the performance.   Initially, this configuration actually appears to be able to lift even more than the SSME variant - a few extra tons per flight :)

I'll have some simulation numbers soon, and I'll post the LEO performance, the GLOW and the liftoff T:W for both variants, but to put it in the ballpark, they're about 1.7:1 and 1.4:1.

Ross.
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Offline JIS

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Re: "Direct" Alternative
« Reply #72 on: 09/11/2006 03:14 PM »
Kraisee, why do you think somebody from NASA would ever listen to your ideas. These were considered few yars ago and find minor to current architecture. Ares 1 is going well so why would NASA consider expensive changes to their architecture?
To be honest I don't uderstand all these EELV fans as well. Does it have anythig to do with popular conspiracy theories in USA? Or is it some kind of psychosa?
'Old age and treachery will overcome youth and skill' - Old Greek experience

Offline kraisee

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Re: "Direct" Alternative
« Reply #73 on: 09/11/2006 03:25 PM »
JIS, I don't expect them to change at this stage - I do think they are well into the process, and that they have sufficient confidence that their current solution will work, so they have no reason to change.

However, I believe Ares isn't the best route from an economical, schedule or risk mitigation PoV.

Most significantly from the cost perspective, Direct completely removes the need to develop any second launch vehicle - and that alone saves $20Bn.   That's some serious cash which should raise some eyebrows.

Not to mention that the initial Direct CLV, does not incur the $4Bn which is having to be paid to develop the new 5-segment boosters.   That's a very hefty near-term cost benefit in Direct's favour too, and with NASA's budget as constricted as it is, this is a nice alternative to consider.

And most critical of all IMHO - the first vehicle opens up the moon.   If the second vehicle is cancelled at any time in the next 12 years in the current plan, we all lose the moon and Mars and will end up stuck with Ares-I launching CEV to LEO alone.   With Direct, the CLV can open up the moon straight away.

Also, having a CLV with 50 tons of extra lift capacity would open up a lot of alternatives which Ares-I will never be able to offer, such as lab modules after ISS is retired in 2016, or free cargo launch capability to ISS at the same time as CEV flights.   Ares-I could not bring up any replacement modules to ISS, or maybe to Hubble.   Direct CLV could.   In fact, Direct's CLV is capable of launching an new full-scale SkyLab if required - it has that much capacity without having to develop a dedicated CaLV.

Those are all enormous benefits over Ares, and while I can support the Ares approach, I think it is worthwhile pointing these benefits out.   And for the record, I know this particular idea has made it on to the desks of significant NASA people in recent weeks.

But I agree, to change tracks now would require something very considerable.   I just happen to think this might be worthwhile enough to do it.

Ross.
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Offline JIS

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Re: "Direct" Alternative
« Reply #74 on: 09/11/2006 03:45 PM »
To understand me correctly before ESAS my favourite SDV was inline configuration with 2xRS-68 under ET and 2x4seg SRBs. But after considering ESAS approach I've changed my mind. Current architecture is better from long term point of view.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #75 on: 09/11/2006 03:53 PM »
Quote
JIS - 11/9/2006  11:32 AM

To understand me correctly before ESAS my favourite SDV was inline configuration with 2xRS-68 under ET and 2x4seg SRBs. But after considering ESAS approach I've changed my mind. Current architecture is better from long term point of view.

Why?   What specific things made you change your mind?

R.
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Offline JIS

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Re: "Direct" Alternative
« Reply #76 on: 09/11/2006 06:02 PM »
Quote

Why?   What specific things made you change your mind?

R.

I've found out that CEV is not the most important stuff for VSE at all. The important tool to do something usefull is LSAM and Ares V.
Yes, it is important to launch people safely, but going safely to LEO or ISS doesn't make big difference. NASA is already there, they can go to ISS using STS or Sojuz twice a year and they don'd need to do more. If STS is not safe enough they cen go to LEO with Sojuz which is unbeatable on price and safety and Americans can buy it. Some commercial companies may soon (in 10years) get there as well.

I think there is no point for NASA to develop manned vehicle for LEO. I think its good idea to have vehicle which is optimised for Moon or close proximity of Earth beyond LEO. This vehicle should be optimised for use with LSAM and Ares V which Orion/Ares 1 really is.
Maybe even more important is to have capability to deliver some significant cargo to the Moon, libration points, close asteroids or Mars in one shoot. And its Ares V.  

Ares V really matters if you want to deliver some real hardware to the Moon not doing randezvous all the time. (Imagine robotic flight with Ares V/Cargo LSAM) That's the reason why I finally left the idea of direct SDV.

'Old age and treachery will overcome youth and skill' - Old Greek experience

Offline kraisee

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Re: "Direct" Alternative
« Reply #77 on: 09/11/2006 06:35 PM »
In some ways I agree.

In a pure clean-sheet environment, I would say build big initially and get going.   But that's not what we have here...

We need an interim solution for launching people as soon after STS is retired as possible, while retaining the workforce.

NASA is certainly leveraging the development of the Stick towards developing the Ares-V later, and that's a great approach.   But they can't get rid of the cost of that first vehicle after Ares-V becomes operational.   It's safety numbers are lower than 1 in 815 - which even the EELV solutions beat.   Look at LV 26 in the ESAS report to work out the safety of Ares-V, and then factor in the EDS on top of it as a complete extra stage.   I've done some analysis of the various options there, and I estimate that adding the EDS reduces the safety number by about 98 points over the basic LV.

So while it will be man-rated, Orion isn't ever actually going to be flying on the Ares-V because Ares-V doesn't reach the required 1:1000 barest-minimum safety standards.

At that point you're spending twice as much as Direct to get the same capability to go to the moon and Mars.

And Direct won't actually cost as much as Ares-I to develop either - you certainly save the cost of the $4Bn to redevelop the SRB's into 5-segment versions, and the rest is pretty-much equal: One stage dev, one engine re-dev, one facilities alteration cost etc.

And what happens if the next President, or either of the two after that, cancels the development of the moon rocket because they'd prefer to spend the money elsewhere?   Ares-I can't get us to the moon.

The "CLV" Direct could.

A single Direct can still launch missions to the moon.   A single Direct+EDS can send approximately ~43mT to the moon, compared to Ares-V's ~55mT.

And with the $20.1Bn you saved by not building a second vehicle at all, you can launch an extra 143 Direct's!

Or you can still use that same money and build Ares-V anyway, on the same schedule as planned already - assuming the political will hasn't dried up.   But if the will has gone, you aren't stuck in LEO.

Ross.
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Online mike robel

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Re: "Direct" Alternative
« Reply #78 on: 09/12/2006 12:13 AM »
Ross, do you percieve changing the ET from a side mount to an inline mount as easy?  It requires different structural requirements as well as the development of new plumbing.  Or Have I missed this as well in your on line posts?

Offline HailColumbia

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Re: "Direct" Alternative
« Reply #79 on: 09/12/2006 12:45 AM »
Quote
mike robel - 11/9/2006  8:00 PM

Ross, do you percieve changing the ET from a side mount to an inline mount as easy?  It requires different structural requirements as well as the development of new plumbing.  Or Have I missed this as well in your on line posts?

Don't we have to do that for ARES V anyway?
-Steve

Offline Norm Hartnett

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Re: "Direct" Alternative
« Reply #80 on: 09/12/2006 01:13 AM »
Hi Ross,

More questions :)

You are suggesting using the RS-68 Regen? I've searched the web and I do not see any indication that this engine has been tested (or built for that matter). I realize that is true for the "disposable" SSME but one of the pluses of Direct is using existing engines initially while the disposable is developed. By switching to the RS-68R don't you lose this advantage? Presumably there is going to be a need to "manrate" the RS-68R further delaying initial ops.
“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 rumble

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Re: "Direct" Alternative
« Reply #81 on: 09/12/2006 03:19 AM »
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kraisee - 11/9/2006  10:12 AM

JIS, I don't expect them to change at this stage - I do think they are well into the process, and that they have sufficient confidence that their current solution will work, so they have no reason to change.
Except for the rumor that the J-2x might delay the first manned flight...  Penning the J-2x's first flight for 2016, while using Direct for CLV opens up the time they might need.

I sure wish we could get them to change.  Think a case of whiskey might do it?  *sigh*

Offline kraisee

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Re: "Direct" Alternative
« Reply #82 on: 09/12/2006 05:40 AM »
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mike robel - 11/9/2006  8:00 PM

Ross, do you percieve changing the ET from a side mount to an inline mount as easy?  It requires different structural requirements as well as the development of new plumbing.  Or Have I missed this as well in your on line posts?

Changing the tanking isn't exactly easy.   It requires a full development cycle including new tanking, new thrust-structure, new payload interface, new avionics, wind tunnel and computer model testing and all the other things which are routinely involved in making any new stage.

But Ares-I U/S and First Stage both require a similar full development cycle, even though the U/S is considerably smaller.   In practice, the development costs are pretty similar no matter what size you're designing for, but Direct does not incur the $4Bn extra overhead for developing the 5-seg SRB's.

In point of fact, the ET-derived stage should actually be cheaper than the Ares-I U/S, simply because considerable tooling already exists for some of the key elements, such as the tank walls, the internal strengthening ribs throughout the tanks, both the upper and lower LH2 tank dome structures, the lower LOX tank dome manufacturing, much of the integrated plumbing for both tanks, and also the intertank structure.

The entire intertank could, I believe, largely remain unaltered, although the additional internal bracing for the Orbiter nose attachment can be removed if that's not too big a job.   The current design of intertank already includes all the forward SRB attachments and the internal bracing to support 4-segment SRB's, plus all the plumbing and integrated avionics bays.   None of that hardware has to be redesigned, it could be re-qualified "as-is".   A slightly more efficient "SLWT" version of the tank can be designed later in the program to remove any unnecessary mass from the structure, but that does not have to be incurred during the critical "lets get something flying ASAP after Shuttle is retired" period.   All the tooling and expertise exists right now to build all of those common elements, and that should prove beneficial to both costs and schedule.

By no means do I consider it 'easy', but it is no more complex, nor more costly, than the engineering being done right now for the all-new Ares-I.

Ross.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #83 on: 09/12/2006 06:11 AM »
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Norm Hartnett - 11/9/2006  9:00 PM

Hi Ross,

More questions :)

You are suggesting using the RS-68 Regen? I've searched the web and I do not see any indication that this engine has been tested (or built for that matter). I realize that is true for the "disposable" SSME but one of the pluses of Direct is using existing engines initially while the disposable is developed. By switching to the RS-68R don't you lose this advantage? Presumably there is going to be a need to "manrate" the RS-68R further delaying initial ops.

Norm, I originally thought the SSME would be the choice for exactly that reason, but I now understand differently.   The same reason why Ares-V went from SSME to RS-68 is what is driving this change:   The fact that production is overly complicated, VERY slow output, and highly costly on a per-unit basis.   I no longer believe that even the disposable SSME could be manufactured in the quantities necessary to support 6 Direct flights per year (18 units/yr), for a reasonable sum of money.

At that point, I had to change to something else.   RS-68 and it's derivatives are the most logical alternative, but I need higher Isp for Direct to perform at its best, and that means the Regen is the unit which fits the bill.

The RS-68 to RS-68 Regen development would be somewhat analogous to the work necessary to re-develop the Apollo-era J-2 into the J-2X today.   An advantage is that the original engine was certainly designed with this particular upgarde in mind for some point in the future, so PWR believe that the Regen version could be created fairly swifty by all accounts.

If however it can't be done as swiftly as we might like, there is always the fall-back option of man-rating the current RS-68 initially, and upgrade to the higher-performance Regen version a little later on - in a similar fashion to the way SSME was upgraded to the Block-II around STS-70 in 1995.   I'd perfer not to do this, as that means the initial performance for Direct drops to only 65-70mT to LEO, but if needs must, it is a stop-gap measure while the LSAM and EDS are being completed - which the budgets would indicate will take an additional 3-4 years after initial manned flights start.   During that period only ISS flights are necessary, so maximal payload capacity isn't so important.   This low-power initial variant of Direct would still launch at least 65mT to ISS, which is more than enough for a CEV and an ATV to fly together, or perhaps offer a means to fly some of the remaining unflown ISS modules to the station after STS has been retired.

The big improvement though, is that RS-68 Regen *can* be put into procduction in the quantities we need, and still will not cost anywhere near as much as SSME.   Per unit costs around $20-25m for the Regen versions should be possible in the quantities Direct uses them, and that doesn't even factor in the possibility that the Delta program could decide to upgrade too and would then share some of the costs.   This switch would drop the recurring cost of Direct from ~$150m per flight down to around $120m - which is roughly the same cost as Ares-I will be - yet even the initial low-power Direct will out perform Ares-I by a factor of 2.6 times the payload carrying capacity!

Further, due to the lower complexity of the RS-68, it is considered significantly safer than the SSME, even with SSME's long history.   Further, because there are now only two powerplants on the core instead of three, the safety is improved again due to lower overall system complexity.

Using the ESAS' own methodology to arrive with new LOC & LOM figures, this change appears to result in substantially improved numbers over the 1:1170 & 1:176 figures Direct had initially.   This new evolution of Direct appears to now be somewhere around 1:1355 LOC, and 1:184 LOM.   Compare those to the basic Ares-V [without the EDS] (ESAS LV#27 at 1:915 LOC, 1:124 LOM) and I believe you will find them very encouraging indeed.

This configuration also appears to slightly improve the overall performance by ~2-3mT to LEO over the previous design - which is nice! :)

Somehow, it seems that the cheaper option is in fact the safer and most reasonable one after all, amazing as it might sound.

Ross.
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Offline meiza

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Re: "Direct" Alternative
« Reply #84 on: 09/12/2006 01:10 PM »
This is what many people were trying to tell you, that RS-68R was still going to be soo much cheaper than a cheapified SSME. :)

I find this quote somewhat related, from the OV-10 story by W.H. Beckett:
"...the "system" will almost always accommodate additions, but never can anything be taken out. This is why all weapons grow in weight, complexity and price; and if something smaller is desired, you have to start over."

By NASA's numbers, the Direct vehicle is still going to be less safe than the Stick, it has two solids...

Offline yinzer

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Re: "Direct" Alternative
« Reply #85 on: 09/12/2006 07:41 PM »
Yup.  But there were computer models of the cheaper SSME, you know.  

I also think that you've hugely underestimated the payload hit; dropping from the 452 seconds specific impulse of the SSME to the 420 seconds of the RS-68 on a stage that has to perform as large of a delta-V as the Direct core stage looks like it should have a payload hit of more like 20 tons rather than 7.  The Ares V had to increase tankage volume by 40% to accomodate the change, and the presence of the EDS as a second stage means that the core stage has to do much less work.

And if you have to shut down the SSME program in addition to the OPF, and whatever conceptual design tools you are using have grossly underestimated the costs and difficulty of modifications to existing Shuttle hardware, maybe it's a good idea to go back and look at other (EELV) alternatives.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #86 on: 09/12/2006 09:50 PM »
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yinzer - 12/9/2006  3:28 PM

Yup.  But there were computer models of the cheaper SSME, you know.  

I also think that you've hugely underestimated the payload hit; dropping from the 452 seconds specific impulse of the SSME to the 420 seconds of the RS-68 on a stage that has to perform as large of a delta-V as the Direct core stage looks like it should have a payload hit of more like 20 tons rather than 7.  The Ares V had to increase tankage volume by 40% to accomodate the change, and the presence of the EDS as a second stage means that the core stage has to do much less work.

And if you have to shut down the SSME program in addition to the OPF, and whatever conceptual design tools you are using have grossly underestimated the costs and difficulty of modifications to existing Shuttle hardware, maybe it's a good idea to go back and look at other (EELV) alternatives.

I disagree.   The higher thrust of the RS-68 Regen means the rocket flies a noticably different trajectory from the SSME variant.   The different trajectories play to the strengths of each engine, and in this configuration the two '68s outperform 3 SSME's.   The Ares-V is not actually going to be flying an optimized design.   The optimal design actually includes a lot more propellant - 15-20% more.   With an optimal configuration (with larger tanking than being planned), Ares-V could loft about 170+mT.   It's going to loft 132mT, because it is actually 'short fuelled'.

The calculations seem to indicate that the Ares-V's design is actually a lot closer to a 4 x RS-68 config, which is logical because that's what you'd want in order to offer single engine-out capability from about T+60s up, which with so many engines is fairly sensible IMHO.

"Direct" actually runs very close to the optimal for 2x RS-68 "Regen" engines, and still offers engine-out from about T+180s up.

And the EDS on the Direct is smaller than the one on Ares-V.   Ares-V requires about half the propellant to be burned during the ascent.   Direct only requires 64% of that ascent propellant, and thus smaller tanking too.

Ross.
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Offline rumble

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Re: "Direct" Alternative
« Reply #87 on: 09/12/2006 11:30 PM »
If the Ares-V switches to the RS-68 Regen at some point, where would that leave things (re: "optimal configuration" and payload to orbit)?

What defines "optimal configuration" as you're describing it?

Offline kraisee

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Re: "Direct" Alternative
« Reply #88 on: 09/13/2006 05:09 AM »
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meiza - 12/9/2006  8:57 AM

This is what many people were trying to tell you, that RS-68R was still going to be soo much cheaper than a cheapified SSME. :)

Actually, it's not the 'unit cost' which is the deciding factor.   It's the fact that 6 Direct's per year, requires a production line capable of churning out 18 units per year, and PWR just can't do that number with their current facilities.   The cost for building or expanding their facilities drives the set-up cost through the roof.   They can turn out about 10 per year maximum with what they've got right now - and that just ain't gonna be enough for this concept.   That's what messed up the SSME concept.

The new "Direct" spec, requires 12 RS-68's to be produced in an already under-utilised production plant, which was supposed to be producing about three times as many units as are being launched currently.

Ross.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #89 on: 09/13/2006 05:21 AM »
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rumble - 12/9/2006  7:17 PM

If the Ares-V switches to the RS-68 Regen at some point, where would that leave things (re: "optimal configuration" and payload to orbit)?

What defines "optimal configuration" as you're describing it?

I'm not actually sure, I'll have to model it some time...

My definition of 'optimal performance' ***in this particular very specific example ONLY*** is purely the maximum payload you can loft, given an optimal Core stage capacity.   The best possible performance for the entire Ares-V configuration (2x5-seg SRB, 5xRS-68 (std) Core, 1xJ-2X Upper), with a longer Core, can loft more payload to LEO.

However, moving stages between the VAB Transfer Aisle and the Highbay probably dictates the maximum limit for the Ares-V.   I would have to guess that's the limiting factor in their current configuration - certainly the Ares-V Core stage is considerably longer than the Saturn S-1C stage was.

If the VAB is not the limiting factor, and the Core stage could actually be lengthened, the 'sweet spot' actually comes with an even larger Core stage.

Ross.
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Offline rumble

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Re: "Direct" Alternative
« Reply #90 on: 09/13/2006 12:57 PM »
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kraisee - 13/9/2006  12:08 AM

If the VAB is not the limiting factor, and the Core stage could actually be lengthened, the 'sweet spot' actually comes with an even larger Core stage.
MLP & flame trench will already have to be changed...so changing the LV's footprint at this point doesn't cause a lot of additional pain.  Could the core stage expand beyond 10m?  ...easier than making the rocket taller...

Offline Jim

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Re: "Direct" Alternative
« Reply #91 on: 09/13/2006 01:40 PM »
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kraisee - 12/9/2006  1:58 AM

Norm, I originally thought the SSME would be the choice for exactly that reason, but I now understand differently.   The same reason why Ares-V went from SSME to RS-68 is what is driving this change:   The fact that production is overly complicated, VERY slow output, and highly costly on a per-unit basis.   I no longer believe that even the disposable SSME could be manufactured in the quantities necessary to support 6 Direct flights per year (18 units/yr), for a reasonable sum of money.

When did you have a change of heart on this?

Offline kraisee

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Re: "Direct" Alternative
« Reply #92 on: 09/13/2006 05:44 PM »
As you say, the MLP and flame trench will need extensive modification to support the 33ft diameter configuration anyway, also all the work platforms in the VAB, the checkout cells also in the VAB, the transportation barge from MAF, and all of the tooling there too - I don't believe any of the S-IC tooling still exists, or would still be usable.

Given all of that has to change anyway for Ares-V, there seems to be little reason why the stage couldn't be virtually any diameter you like - as long as it fits through the Highbay doors!   I don't see much difference in costs between 10m, 12m or even 15m wide.

The height would ultimately be dictated by the amount of propellant you want, and the height you need the interstage at in order to support the fwd SRB mounts.

The only *major* cost difference comes if you choose not to change any of what's there right now, and stick with 27ft - in which case you don't need to spend virtually any of that money at all.   There are big savings to be had that way, in the order of $2.5Bn when you also factor in the new MLP's specifically being designed for Ares-I, and the new Crawlers too.

Not to mention that 5 MLP's, each with a Launcher/Umbilical Tower, will require 2.5 times as much in annual maintenance costs as just two Fixed Service Structures permanently located at each Pad.

Ross.
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Offline kraisee

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Re: "Direct" Alternative
« Reply #93 on: 09/13/2006 06:09 PM »
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Jim - 13/9/2006  9:27 AM

Quote
kraisee - 12/9/2006  1:58 AM

Norm, I originally thought the SSME would be the choice for exactly that reason, but I now understand differently.   The same reason why Ares-V went from SSME to RS-68 is what is driving this change:   The fact that production is overly complicated, VERY slow output, and highly costly on a per-unit basis.   I no longer believe that even the disposable SSME could be manufactured in the quantities necessary to support 6 Direct flights per year (18 units/yr), for a reasonable sum of money.

When did you have a change of heart on this?

Jim, let me explain my thought process on this...

The figures for the regular RS-68 just don't work well with this concept (dropping payload for the basic variant to 67.9mT to 28.5d, 60x160nm), so I had always discounted those as ultimately workable - they would mean this concept would be a 3-launch solution, and I'd disqualify it myself at that point.   But in a discussion on here a few weeks ago, I agreed that higher Isp version of the RS-68 would probably be compatible.   That discussion got me researching the options, and the Regen looked possible, although SSME was still my preference due to lower development costs and faster availability.

Recent information indicated the limitations of the maximum possible production capability for PWR's SSME line would not be able to support the necessary 18 units per year to duplicate the ESAS missions (6 launches: 2 ISS, 2x2 Lunar/yr).   That instantly discounted the SSME from consideration right there and then, even though it had been the clear front-runner.   If we couldn't fly more than 3 launchers per year, it wasn't ever going to work!

So I was left with a high Isp version of the RS-68 as the lone alternative.   I was at first doubtful whether even the estimate of ~440 Isp expected from the Regen '68 would be sufficient, but I decided to perform the sims anyway, just reducing it a bit for 'safety'.

Even at around 432s vac Isp, the Regen '68 matches the performance of the SSME in this configuration of booster, and does so with 2/3rds as many engines as the SSME solution.   That's a "win-win-win" situation on all three key factors: cost, safety, production capacity!   How could I turn that down? :)

So I obtained some real figures on the RS-68 Regen concept from a few friends who work at PWR, and plugged them into my design. I'm not allowed to publish them, but I'll say the initial estimates were about right :)

The sims indicate that these engines would work extremely well indeed, and would exceed the performance of the 3xSSME variant.

One factor I've had to address is the fact that the Regen will take time to fully DDT&E - in the order of 5 years.   So my solution is to create a man-rated version of the current RS-68 which could fly considerably sooner in order to support the earlier missions which are only going only to ISS anyway, and don't require the maximum performance anyway - 67.9mT is certainly more than enough for any ISS mission!

By the time the EDS and LSAM are ready for testing, the Regen engines should already be flying.   And the qualification process for the basic man-rated RS-68 configuration would seriously benefit the qualifiaction program of the Regen later as many of the individual parts would be common between the two engines.

I'm not planning for DoD to share any of the costs for this though.   This is because I see even higher performance than I've assumed here being possible if the nozzle is designed specifically for higher altitude operation, instead of the high SL performance of the current RS-68 nozzle.    That sort of change would not offer any benefits to the Delta-IV at all, so I'm making a basic assumption that the Regen is exclusively for Direct, and that Direct picks up all the costs involved in its development.

I've now got to tie-down all of the costs, because the development and operating costs have all now changed and all my previous tables are no longer current.   I should have some preliminary new figures some time later this week though.

Ross.
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Offline kraisee

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RE: "Direct" Alternative
« Reply #94 on: 09/13/2006 11:52 PM »
I gave up working today, because I wanted to do this instead!   Bad Ross! :)

I've prepared some new Budget analysis figures for Direct.   Only preliminary at this stage, I still need to fine-tune things, but I actually think it's pretty close.

First is the Current Ares Budget.

Second is Direct planned fly the same dates as Ares will, which saves near-term money.

Third is an expedited development, within the same Ares Budget we plan to spend anyhow, but which (by removing the costs for developing a second vehicle) accelerates the first CEV flight by one year (to 2013), and the first Lunar flight by two (to 2016).

R.
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Offline rumble

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Re: "Direct" Alternative
« Reply #95 on: 09/14/2006 01:39 AM »
Quote
kraisee - 13/9/2006  12:56 PM

I'm not planning for DoD to share any of the costs for this though.   This is because I see even higher performance than I've assumed here being possible if the nozzle is designed specifically for higher altitude operation, instead of the high SL performance of the current RS-68 nozzle.    That sort of change would not offer any benefits to the Delta-IV at all, so I'm making a basic assumption that the Regen is exclusively for Direct, and that Direct picks up all the costs involved in its development.
So the "stock" RS-68 has isp ratings of 365 & 410 for sl & vac, respectively.  You mentioned a somewhat validated guess of the RS68regen's vacuum isp of 440.  Does that improvement cause the sea-level isp to suffer, and if so, by how much?  (or can you say?)

Losing some sea-level isp doesn't affect the LV nearly as much as missing some vacuum isp.  Sea level is where the solids shine, anyway, so let them help push us out of the atmosphere.

Offline kraisee

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Re: "Direct" Alternative
« Reply #96 on: 09/14/2006 03:41 AM »
Rumble,
   The numbers I've gotten so far are for a Regen version of the current nozzle.   It doesn't appear to hinder the SL performance at all, in fact the SL performance seems to rise by a similar percentage as the Vac number, not quite as much, but not far off.

   I assume this particular design its meant to be used as an upgrade option for Delta-IV.   Because of that, it is still more optimized for SL operation than for Vac.

   While I don't have any specific information to confirm it, there ought to be a performance increase above my current figures if the nozzle were to be custom-designed for Direct's application.

   But I have no idea what sort of performance gain might be achievable by doing that.   All I know is that the numbers I've used in my sims are without that increase factored in.

R.
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Offline simcosmos

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Re: "Direct" Alternative
« Reply #97 on: 09/15/2006 09:53 AM »
Hello

[side note]
In my virtual projects I always preferred the expendable SSME approach - when comparing with current RS-68 and possible derived engines - because, in virtual world, there are not the constraints of real world and the SSME path, for +/- obvious reasons and once removed those recently reported production constraints, would probably still be a better choice from the performance point of view (and allow the same ET diameter to be used, less VAB / MLP mods, etc)
[/side note]

However, looking at these expected / possible RS-68 upgrades and all other constraints I'm also starting to "change my heart" about the RS-68 vs SSME discussion (even for the virtual projects). Here go a few doubts / extra comments related with real world applications and Direct (please someone feel free to correct if I wrote nonsense):


1) Ares V, in its last known format, has a 10m main diameter mainly because of the lower ISP of the RS-68 that is expected to equip its core (when comparing with SSME variants), at least in the first missions. This means that if the RS-68 engines see a future upgrade where their ISP will be closer to the 440s or even about 450s we will then have a kind of bonus performance (more efficient engines, even more thrust for ascent trajectory options, more payload mass).

By other hand, if there could be a way of supporting the near-term (hummm… 6 to 10 years?) development of eventual "vacuum optimised / higher ISP" RS-68 derived engines, the AresV design could also be back to the ~8.4m STS ET diameter: this would allow for less modifications in the support structures, etc and the delivered payload would still be good although, having the bigger 10m diameter with upgraded engines (and even more payload potential) is also something to have in mind despite all other modifications required and the possibility of eventual first AresV missions using non fully optimised RS-68 engines.



2) Anyway, both J-2X and eventual RS-68R variants (regenerative nozzle and other upgrades) can virtually be considered as being new engines, despite their designations and heritage, yes? no?

Focusing in the RS-68R: would that upgraded engine be as easier and cheaper to produce when having in mind an expendable SSME or other eventual options?



3) Somehow related with the above question and the information in one of the previous posts, one doubt: if there would be a maximum production limit of 10 SSME per year how could the ESAS recommended approach be about the adoption of an expendable SSME for the CaLV and an also expendable but even more challenging (air-start capability) SSME for the CLV? (even considering the possible modifications of extra engines from STS program and the mention that some of the changes would be "easy" >>> hummm)

I mean, just for the CaLV and 2 missions / year = 10 SSME: this not considering the modified SSME for the original CLV and possible extra CaLV launches, if the conditions exist in a given moment. Was not ESAS team aware of those production limits?

I still have to re-check this but I guess that if the SSME path was chosen the production capability would have to be there or (re)created as necessary although I understand that such option seems much less attractive when looking at existing RS-68 production and upgrades potential.




Now back to Direct:

Ross, for the first addon release I'm thinking that it would be fun to include both versions of the ET core (SSME + RS-68R). This way people woul' be able to compare launcher’s performance, ascent trajectory tweaks, etc.

Regarding the RS-68R: made a clumsy and very simple model of it by adapting the previous (also simple) SSME work. Nothing too fancy or 100% correct (I do not wish to spend more than a given modelling / time budget with the engines) but it should be enough to visually difference it from the SSME based core: please see the current picture in my LivePics page (later to be moved to the flickr photo set, with respective comment added).


About the rest of the work in progress with the Orbiter simulator addon: as interested readers have noticed, the rhythm slowed down a bit and will continue that way (mostly a weekend progress now).

I already have the other components converted to Orbiter's 3D / texture format: just need now to finish the ET adaptations and convert them too (and there is also the alpha pad conversion). Then will come a slightly boring part: to build a good directory structure for all files (to avoid Orbiter default files to be overwritten and to allow for easier addon maintenance / upgrades) and to start assembling the rocket.

I should perhaps show some wip pictures about that in the LivePics... People will first see the pair of SRB in Orbiter's default pad39 (if meanwhile I do not convert my custom pad), then the ET core will appear in the middle, then either the cargo fairings or the SLA + CEV + LES and so on.

A much interesting phase will start once all that done: performance and guidance tests, some of them also planned to be transmitted "live" ;)

(slow) work in progress,

António
my pics @ flickr

Offline kraisee

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Re: "Direct" Alternative
« Reply #98 on: 09/15/2006 05:38 PM »
António,
Good to have you back with us :)

RS-68:
The RS-68 ultimately costs about one quarter of the cost of the SSME, in the same production quantities, up to about 10 units per year.   More than that, and the price sky-rockets for the SSME, but remains relatively constant for the RS-68.

The RS-68R (I like that way of refering to it) will cost about 1/3rd as much.

All I can do is roughly calculate the approximate prices using that guideline:   Assuming the $20m NASA figure for a man-rated RS-68, that means the SSME cost would be about $80m each, and the RS-68R would be about $26.5m each.

And yes, RS-68R would require a full development cycle, just like J-2X does.   Its slightly cheaper than building an all-new engine, but not much.   The real advantage is you know it is based on something which did work previously.


Direct:
Both version sound like fun to have avaialble in Orbiter, but could I ask you to prioritise the '68 version first, and then when it's finished, do the SSME version?

What you've got there right now is certainly close enough to the final configuration that it should demonstrate quite nicely how this beastie flies! :)


Ares-V:
There is currently no money going to be left over to allow the Regen to be developed for the Ares-V.   While it would certainly increase its performance too, if it can't be paid for, it doesn't matter.

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

Offline josh_simonson

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Re: "Direct" Alternative
« Reply #99 on: 09/15/2006 11:45 PM »
If simcosmos uses a standardized template for his Orbiter sims, you'll be able to plug and chug any numbers you want for thrust, isp and fuel capacity to simulate various direct LVs.  In fact any standard 2 stage rocket model can be used for this sim with decent accuracy.

Getting pretty pictures is alot more work than getting performance info out of orbiter.

Offline spacediver

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Re: "Direct" Alternative
« Reply #100 on: 09/16/2006 12:50 AM »
Hello Ross

Obviously there was pretty much business in this forum during my almost-two-week-swizerland-non-diving-due-to-illness-holyday... :)

It’s nice to see your direct scenario taking more and more shape, specially your switch from SSME to RS-68R!
I still see a problem in the mass of rendezvous and docking maneuvers necessary in earth orbit. The problem was discussed earlier in this thread.

I think it’s time to add my 2-launch lunar orbit rendezvous mission concept to your direct scenario. If you remember I mentioned this concept in the other thread but the discussion focused on the launch vehicle design and the different mission scenario was almost forgotten.

Here’s my proposal:
Keep the two launches but launch the LSAM and the CEV separately into the lunar trajectory. The LSAM would Launch first, would perform the LOI and wait in lunar orbit. Later (up to 60 days if necessary) the CEV would launch the same way, perform the LOI and dock with the LSAM for crew transfer. The rest of the mission would be the same as the ESAS scenario.

This would require a (smaller) EDS stage on both of the launches but would increase mission flexibility.
The propellant load on the CEV’s service module would have to be increased because it have to perform the LOI burn on it’s own. A delta-v-capability of about 2500 m/s should be sufficient.
On the other hand the propellant load of the LSAM can be reduced as it has to perform the LOI burn without the CEV attached.

The advantages:
- Lower mission complexity!
- No docking maneuvers in earth orbit necessary.
- No circularisation burn of payload stack necessary.
- The two launches do not need to be performed within short time. The LSAM can be designed to wait inactivated in lunar orbit up to two months.
- Same mission profile for unmanned one way LSAM flights. Just no CEV docking in lunar orbit!

The disadvantages:
- EDS stage needed on both launches.
- No lifeboat available for CEV during lunar coast phase.

I will run the numbers when I find the time!

Spacediver

Offline kraisee

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Re: "Direct" Alternative
« Reply #101 on: 09/16/2006 04:11 AM »
SD,
It's a concept I've considered, but I'm yet to be convinced.   I think it would have to go to a trade study to be properly compared, but in the absense of that - convince me! :)

Here are some spec's for what each Direct can actually do:-

EDS massing 19.0mT, including one J-2X and RCS.   Performance of the J-2X is assumed to be 448s vac Isp, and 294,000lb vac thrust.

Configuration can carry NET 92.9mT of payload and fuel to fully circularised 160x160nm 28.5deg orbit or 94.4mT to 100x160nm 28.5deg.

Run the numbers and tell me what you think it can do in this configuration.

R.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline simcosmos

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RE: "Direct" Alternative
« Reply #102 on: 09/16/2006 12:18 PM »
Quote
josh_simonson - 16/9/2006  12:32 AM

If simcosmos uses a standardized template for his Orbiter sims, you'll be able to plug and chug any numbers you want for thrust, isp and fuel capacity to simulate various direct LVs
(…)
Getting pretty pictures is alot more work than getting performance info out of orbiter.


Yep, josh_simonson is right: what takes more time here is not the actual process of implementing the numbers (empty + propellants masses of the components, engines thrust, ISP or even to *code* some eye-candy features such as the engine's exhausts).

All that is quickly done (yes, I have already prepared standard files for that stuff from my NASA VSE SC addon v2.0 wip) and everybody will be able to easily have a look at those numbers because, despite having some programming experience, I never touched in c++: this means that the physical behaviour of Direct launchers will be implemented via an alternative *coding* approach called Vinka's Generic DLLs (in this case, multistage.dll from http://users.swing.be/vinka/ ). People will then be able to use notepad to simply open a structured INI text file where almost all parameters will be self-explanatory (will also add my own comments).


Doing the 3D models and textures is also something relatively quick here too (but some delays were added due to a few extra tweakings with the ET core + SRB updates): I'm trying to not exaggerate too much in the number of details and keep the visuals somehow simple but still with some *coolness* factor ;)


What is taking a little more time is really the conversion process, just because I'm very, very comfortable (after trying other options) with using the freeware Anim8or ( http://www.anim8or.com ) as my favourite 3D editor but, at least until now, it does not directly export to .msh (Orbiter's native 3D format) like some of those other options (gmax, blender, etc). This means the introduction of a middle step where I must first export to 3ds and from there to msh.

Also: some post-conversion and manual editions / tweaks to the meshes are needed (by opening the converted msh with notepad to, for example, add a few cool material properties). I also wish to prepare a more or less solid directory tree (instead of just droping all files into Orbiter's default sub-folders) plus, at the same time, start documenting all so that later addon upgrades (or addon uninstall) are easier to do: this is not a very common practice but there are several advantages (but it also takes more time to prepare all though).


So, in this moment, I have already converted all needed components to Orbiter msh format (including updated SSME and RS-68R ET core variants): next step is to build the directory structure and update the texture references inside the meshes (again, opening them with notepad). Then will build the launcher's INIs: not much extra work to do the SSME variant at the same time ;)


Quote
josh_simonson - 16/9/2006  12:32 AM

In fact any standard 2 stage rocket model can be used for this sim with decent accuracy.


Things are not so directly done when playing with solid boosters: there is the thrust curve simulation (that I didn't simulated in my previous and already kind of ugly and outdated NASA VSE SC v1.0). There are two ways of implementing such curves with multistage.dll: for Direct launchers I will use multistage's dll supported thrust curve feature (but with a max. limit of 10 points >> had to adapt a real life curve to that resolution) and reuse some of my past research (it requires a few tweaking to make it work more or less ok). But yes, I agree, if things are properly implemented and depending of the method, Orbiter is a very good tool to realistically simulate an entire mission (for example, there are people out there flying Apollo missions by the numbers) :)




About mission profiles for ISS, Moon, etc and also... possible Direct live tests!

Like Ross wrote, we talked a little about misson profiles in our emails. For now we are mostly trying to create some basic structure (the basic launcher configurations) and more or less follow 'standard' mission profiles to ISS and Moon (with the necessary changes regarding Direct) and also trying, as a starting point, to keep the CEV-LSAM more or less as per ESAS specs due to a number of reasons (one of them is the availability of a good addon with fully functional CEV and LSAM, by Franz Berner aka Francisdrake).


About lunar missions:

I still haven't exported an EDS but I agree: this requires some number crunching. As noted above, a split mission presents advantages (even from the simulation implementation point of view, hehe). However, to optimise the split architecture, some changes would probably be needed to the *standard* CEV-LSAM designs (I would have to make my own implementations of those designs, even using some recent public info but that would take more time than just integrating an existing addon). We can talk about that in a later phase.


That is why I can't wait for having the basic launchers and pad implemented inside Orbiter: the real fun will start once that done, with at least the development of automatic guidances for some ascent profiles and other funny things like TLI setups, middle course corrections, lunar orbital insertion...


Note: with extra work, almost all orbital procedures can be fully automated (another option is to just use the playback feature introduced in Orbiter2006)



About Live Tests!

Again, the really interesting part of Direct simulation is still to come (not counting with the addon's v1.0 release): if having time availability, will use my LivePics to share tests (images refreshed every 10s) and perhaps, hummm... Perhaps a few selected persons, if interested, might even have direct access to telemetry download (from my Orbiter session) and to live voice communications (like if seating in a Mission Control Center) but that is a matter for a future talk.

Warning: beyond the launch phase, space operations might be boring for most of the persons (even if using time acceleration during the coast phases).


Anyway, if any orbinaut / nasaspaceflight reader is around and knowing how to use virtual mission control…



...or wanting to host voice communications (Ventrilo, TeamSpeak) for live Direct test (to ISS, to start with), feel free to email me (please include Orbiter Direct Sim in the subject). Maybe we can prepare a simulated launch event (limited number of persons for telemetry feed and voice comms, unlimited for LivePics).


Ho Ross, by the way: if you still have that word document I sent to you, please update the masses + ISP + thrust + other eventual changes for the twin RS-68R core and send it in my way ;)

Work in progress... Maybe I can have something inside the simulator by today / tomorrow (else we all have to wait another week)

Thanks,
António
my pics @ flickr

Offline kraisee

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RE: "Direct" Alternative
« Reply #103 on: 09/16/2006 10:09 PM »
Looking forward to the Orbiter sims when they're ready.   In the mean time, here are some of the graphs from the calculations of the basic 75mT CLV launcher, going to 60x160nm (111x296km) 28.5deg:

R.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Online mike robel

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Re: "Direct" Alternative
« Reply #104 on: 09/16/2006 10:26 PM »
Ross,

Now that you have gone to RS-68s, I don't see much difference between this and Ares V, except that, if I understand things correctly, you are only going to use 2 RS-68s vice 5.  In fact, it looks like this alternative (as well as your original concept) was previously evaluated in the ESAS or Atlas Studies.  If you don't mind, as I seem to learning impaired following all this, please summarize the differences between Ares V, your original concept, and the Direct/RS-68 Concept.

Mike

Offline Zachstar

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RE: "Direct" Alternative
« Reply #105 on: 09/16/2006 10:51 PM »
SimC if wanting to do some live tests with the guys here I believe we ought to set it up on a schedule so that the people here will have a chance to look into this.

BTW Thanks alot SIMC!! Now I got the "long post" virus. Hehe

-------Voice Communication-------

When I was JPL in VUSSP (Its gone now) I quickly discovered that Teamspeak just aint gonna cut it.

#1 Its butt ugly.
#2 Uses lots of bandwith.
#3 That use of bandwith still means bad quality.
#4 Large problems with my soundcard because I usually leave DirectSound off (It causes my computer to hard crash and restart on games like Silent Hunter 3)

I love Vent! but it seems to not work all that well anymore.

-Google-

So obviously I go to google and start a big search this leads to what im about to talk about.

-Teamtalk-

http://www.bearware.dk/

I tend to prefer this to the others for many reasons.

#1 Extremely nice sound quality (Important when talking things like Direct details)
#2 Nice Looking!
#3 Extremely little bandwith use. (There seems to be no selection for quality but i've discovered it uses around 2.5 Kilobytes a sec for a single person talking.

-Teamtalk Server Hosting-

BigDas has been nice enough to set up a teamtalk server in the past. It diddn't work as nobody was really interested http://orbit.m6.net/Forum/default.aspx?g=posts&t=8106 (I could tell nobody bothered to try Teamtalk as it was just Teamspeak and Vent talk) So maybe we could contact him again to ask if he could host one for this type of event?

------VMC---------

VMC is getting an update!

http://orbit.m6.net/Forum/default.aspx?g=posts&t=2908

As you know VMC can take a bit of bandwith so I suggest people use at max 250ms update during the demo.

--- Final Thoughts ---

I am very lnterested in being in the room watching you fly this stuff. I can remember that time where you showed me your VSE work via MSN and that was great fun!

Looking forward to all this.

Offline kraisee

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Re: "Direct" Alternative
« Reply #106 on: 09/17/2006 12:09 AM »
Quote
mike robel - 16/9/2006  6:13 PM

Ross,

Now that you have gone to RS-68s, I don't see much difference between this and Ares V, except that, if I understand things correctly, you are only going to use 2 RS-68s vice 5.  In fact, it looks like this alternative (as well as your original concept) was previously evaluated in the ESAS or Atlas Studies.  If you don't mind, as I seem to learning impaired following all this, please summarize the differences between Ares V, your original concept, and the Direct/RS-68 Concept.

Mike

Actually, the EOR-LOR option discussed in the ESAS is based on the SSME variant of this - but nowhere in the ESAS report is a version of this with an EDS included.   An EDS is *never* accounted for, and that is why they dismissed it.

The basic ~75mT version of this could NOT launch a Lunar mission in just 2 flights, but when you use an EDS on one of the flights, you *CAN*.   In fact it lifts even more payload to LEO in the two launches as the 1.5 solution can!   Two Direct launchers can start a Lunar mission with approximately 188mT IMLEO.   Ares-I and Ares-V will start a Lunar mission with about 175mT IMLEO.

If you fly with an EDS on each of the Direct's your IMLEO climbs to 226mT, still in just two launches.

And for single launches, a single Direct can send 85% the same mass to trans-lunar trajectory as Ares-V can.

But the *BIG* difference is Direct costs less than half as much to develop, and less than half as much to operate annually as Ares-I and Ares-V together.

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

Offline simcosmos

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RE: "Direct" Alternative
« Reply #107 on: 09/17/2006 12:23 PM »
And another work in progress 'report':

As the regular visitors of my LivePics page noticed, I'm still doing a few tweaks in the alpha pad version for Direct but it is not quite ready yet for a first export and, because of that, will continue to use Orbiter's default launch pads for the first tests.

Regarding the launchers: a basic cargo variant (powered by twin RS-68R) is already flying inside Orbiter simulator. Also made a very early version of an automatic guidance (more or less based in the pitch table posted above). The results seemed acceptable for a first run but there is still a lot of space for optimising the guidance and also some aspects related with the numbers implementation (by the way, using 76000Kg as a test mass for the payload) and also space to tweak the eye-candy (the exhausts are not implemented yet).

Meanwhile, had to go back to the 3D editor to fix some aspects of the SRB and ET core(s): there were one or two rendering issues inside Orbiter but I think that will fix that. Also added a few more clumsy textures.

Still related with the first tests, I'm having a few problems with the dynamics of SRB and payload fairing separation (hummm, probably caused by a bad number or signal somewhere in the related configuration parameters… must re-read multistage.dll documentation… researching the issue)




Live Development Session

During today's afternoon (somewhere between 14:00GMT and the 18:00GMT, Portugal = GMT+1, http://www.worldtimezone.com/index24.html ) I might transmit some flight tests (not 100% sure yet)...

If doing so, it will be a development session and not a demo session: the difference is that a development session might be characterized by stopping the simulator several times, going back to notepad to tweak the guidance or launcher's configuration files, then back to the simulator, etc. Perhaps will also implement the Direct CLV (again, not sure yet).

So, if transmitting something today, it will then not be a demo session, where all would be simulated like if doing a proper mission or where all items would be already integrated in the simulator (like payloads, custom pads, etc).


Perhaps such proper demo session can be made by next weekend: it would then be a good time to:

  • use voice comms (I checked your link Zach, downloaded + installed the program, haven't tried yet but, by the docs, it seems ok and very easy to use)

  • transmit some live telemetry for a selected group of people

  • and, of course, LivePics for everybody



An ISS mission can be simulated in 1 or 2 hours (in real time, if using a very good launch window or if using time acceleration to skip the coast phases)

This gives about one week for all interested persons to download and try the voice program, if wanting to listen the launch / mission comments: any volunteers to host the voice comms? (better that communications are not hosted by the same person running the simulator and telemetry server)

Direct live telemetry will only be transmitted to persons I already 'know' and if requesting it (sorry about the limitation but Virtual Mission Control has a remote control feature and I do not wish that funny people mess up the simulation by playing with that :) )

All for now: if possible, will then try to show - via LivePics - some Direct stuff flying in Orbiter sim, later today ;)

António

Edit: uploading here two screenshots from today's non-continuous  development session. The basic Direct variants (RS-68R) are now more or less flying ok (models, textures, performance, etc) but there are still many details and tweaks to do (materials, guidance, payloads, some things related with eye-candy, payload fairing separation dynamics, etc).

More dev stuff (and perhaps new toys? hummm an EDS + launch pad would be cool) just by the next weekend, if all goes well. Bye for now ;)

my pics @ flickr

Offline Zachstar

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RE: "Direct" Alternative
« Reply #108 on: 09/18/2006 02:36 AM »
Is there a difference in the flame from an RS-68R compared to a classic RS-68?

[img=http://msnbcmedia.msn.com/j/msnbc/Components/Video/041221/n_delta4_launch_041221.275w.jpg]

[img=http://www.orbireport.com/Portraits/Delta_4H.jpg]

If not you might consider using Francisdrake's texture or invent your own. The blue has gotta go :P

Online MKremer

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Re: "Direct" Alternative
« Reply #109 on: 09/18/2006 03:16 AM »
The -68R is almost complete combustion. correct? That would mean shorter visual wavelengths for the exhaust, thus more blue (more like the shuttle SSMEs).

Offline rumble

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Re: "Direct" Alternative
« Reply #110 on: 09/18/2006 03:55 AM »
I had always assumed the stock RS-68's flame had that reddish tint (instead of clear w/the blue shock wave thingy like the SSME or J-2) because of the ablative nozzle, but that's only a guess on my part.

Offline kraisee

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RE: "Direct" Alternative
« Reply #111 on: 09/18/2006 04:00 AM »
António, that looks real sweet!

Thanks for all your hard work this weekend.   I have been unable to get online today, until now (>11:30pm EDT), but you've worked wonders on that simulation.

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

Offline Zachstar

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Re: "Direct" Alternative
« Reply #112 on: 09/18/2006 06:20 AM »
Quote
MKremer - 17/9/2006  10:03 PM

The -68R is almost complete combustion. correct? That would mean shorter visual wavelengths for the exhaust, thus more blue (more like the shuttle SSMEs).

Quote
rumble - 17/9/2006  10:42 PM

I had always assumed the stock RS-68's flame had that reddish tint (instead of clear w/the blue shock wave thingy like the SSME or J-2) because of the ablative nozzle, but that's only a guess on my part.

Great points!!!

I'm very curious about this as I hope to see direct as realistic as possible. So I have taken a photo and did some transparency and color work to test out this look. I have included several color variations but do not incude any shock cone stuff.

Hope this can engage minds and find out what a "realistic" look ought to be to get to SimC.

----Wiki Is Cool-------

Edit: I found this image on Wikipedia. shows a bit "cleaner" flame

[img=http://upload.wikimedia.org/wikipedia/commons/thumb/4/4d/RS-68_rocket_engine_test.jpg/250px-RS-68_rocket_engine_test.jpg]

http://upload.wikimedia.org/wikipedia/commons/4/4d/RS-68_rocket_engine_test.jpg

Offline Zachstar

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RE: "Direct" Alternative
« Reply #113 on: 09/20/2006 08:36 PM »
I hope I diddn't stall the topic. Any ideas about the flame look?

Offline simcosmos

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RE: "Direct" Alternative
« Reply #114 on: 09/22/2006 12:01 PM »
Quote
Zachstar - 20/9/2006  9:19 PM

I hope I diddn't stall the topic.


From this side of the Net I only make Direct updates on Fridays and/or weekend: almost impossible to make Direct related stuff during the regular week now.


Quote
Zachstar - 20/9/2006  9:19 PM

Any ideas about the flame look?

The exhaust texture in the LivePics screenie above is just one of Orbiter's default .dds. Unless someone working in the field gives more precise input about how the RS-68R flames could look like the objective here is to go with something *blueish* and semi-transparent (as also mentioned in previous posts).

I might also try to add some semi-transparent particle settings just to serve as a representation for the part of the flight in the lower atmosphere but it seems that, for some reason, I'm not being able to load all the textures I wish to create that effect with multistage2.dll.

So, for now, I just recompressed one of those nice textures made by mcwgogs...

http://www.orbithangar.com/searchid.php?ID=1494

... still must contact mcwgogs or perhaps even make my own custom texture (need to change a few texture visuals).

Meanwhile, fixed a few little things (such as payload fairing separation dynamics) but more tweaks and test flights are needed for the rest. This weekend will also try to convert a first alpha version of Direct's pad and perhaps also to implement one EDS.

Also updating the sounds: using the latest STS launch as inspiration for the final countdown (-20s) and new SRB sound wave. These will become my new default sounds for NASA VSE SC v2.X too (much better results than NASA VSE SC v1.0). Will probably also use other videos to extract sounds for extra key events such as SRB, LES / PLF and spacecraft/payload separation.

Another thing that must start doing is to clean the files and directory structure plus update documentation to keep track of all files.

I might produce a low quality demo video to show some of these features and temporarily upload it in my webspace (not sure).

Work in progress,
António
my pics @ flickr

Offline Zachstar

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RE: "Direct" Alternative
« Reply #115 on: 09/23/2006 04:02 AM »
Quote
simcosmos - 22/9/2006  6:44 AM

From this side of the Net I only make Direct updates on Fridays and/or weekend: almost impossible to make Direct related stuff during the regular week now.

Hey it's atleast somthing. Over the week you can think of ideas then friday-sunday you realize them! Works for me! This idea is starting to sound so real and realistic that it's really worth the wait! Apollo 9 Direct Style! Here I come!


Quote
The exhaust texture in the LivePics screenie above is just one of Orbiter's default .dds. Unless someone working in the field gives more precise input about how the RS-68R flames could look like the objective here is to go with something *blueish* and semi-transparent (as also mentioned in previous posts).

Sounds like a good plan but you might want to make it REALLY light blue and bright. The reason I say this is the SSME videos with ground cameras and SRB lookup cams show a really bright flame that has a hue of blue in it. I don't know if the RS-68R is similar but the flame ought to be similar for the effect.


Quote
I might also try to add some semi-transparent particle settings just to serve as a representation for the part of the flight in the lower atmosphere but it seems that, for some reason, I'm not being able to load all the textures I wish to create that effect with multistage2.dll.

perhaps a mix of paricles and textures can be called to also show a bit of a shock cone effect? Hope you get the texture problem fixed :(

[/QUOTE]

Quote
So, for now, I just recompressed one of those nice textures made by mcwgogs...

http://www.orbithangar.com/searchid.php?ID=1494

... still must contact mcwgogs or perhaps even make my own custom texture (need to change a few texture visuals).

I love those textures as they are very nicely made and adaptable.

Sounds like a great plan SimC! I hope he grants you permission.


Quote
Meanwhile, fixed a few little things (such as payload fairing separation dynamics) but more tweaks and test flights are needed for the rest. This weekend will also try to convert a first alpha version of Direct's pad and perhaps also to implement one EDS.

You have like 3 different EDS models right? Can you please show us a quick Flickr pick of the EDS you have chosen?


Quote
Also updating the sounds: using the latest STS launch as inspiration for the final countdown (-20s) and new SRB sound wave. These will become my new default sounds for NASA VSE SC v2.X too (much better results than NASA VSE SC v1.0). Will probably also use other videos to extract sounds for extra key events such as SRB, LES / PLF and spacecraft/payload separation.

*Drools* I just love that sound and am VERY looking forward to the results Direct will have with this updated efforts! Thanks alot!!

So now the rocket will REALLY seem alive!

Quote
Another thing that must start doing is to clean the files and directory structure plus update documentation to keep track of all files.

I can't thank you enough for doing this! I had to reinstall the Early ISS Missions pack because an add-on overwrote one of the payloads.

Quote
I might produce a low quality demo video to show some of these features and temporarily upload it in my webspace (not sure).

I request that you not have audio and show the great "sound" you have put into there. Id much rather have no sound then to hear what low quality sound will do to the mix you have done with the NASA videos.

However I am very much looking forward to the demo video! It will be very interesting to see this in action!

Quote

Work in progress,
António

As usual  ;) Btw Have you seen this "Orbiter Mesh Wizard" Program? http://orbit.m6.net/Forum/default.aspx?g=posts&t=9880 Might help with some alignment stuff or whatnot.

Offline simcosmos

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RE: "Direct" Alternative
« Reply #116 on: 09/23/2006 10:06 AM »
Quick answers:

Direct's work rhythm: yep, just weekends now and when possible (argh, having some heavy thunderstorms here during this weekend = power losses). Note: I still try to work a little in other projects during the week (such as MarsOz), but that is other kind of workload / requirements.

EDS model / performance: will produce a new one, just for Direct (that should be a matter of 5 minutes or so). Will reuse some of my previous work with the J-2S and add a nozzle extension, etc to represent the J-2X. Not 100% sure yet about the propellants quantity: have some input about this from Ross but will also try to do a few experiments. There are also a few size constraints in what regards the EDS length: will study all and come up with something. Then Ross and I will surely further fine-tune the design but what I prepare now should be good enough for a first version. Also have to create custom top fairings for the EDS (by cutting the standard PLF).

Flickr Photo Set: still have to upload previous development pictures that were available at my site's LivePics. The new EDS will first be shown in the LivePics and then moved to the flickr photo set as well.

Direct demo video (CLV): I'm delaying it because would also like to have the alpha launch pad ready and tweak a little more a few aspects of the automatic guidance, in particular the roll program and specific portions of the ascent / pitch program. I might produce a first version of the video with Orbiter's default launch pad though.

Regarding sound: I will include the new sound! The compression factor should not be that bad and this will just be a quickly made demo, nothing too much fancy (aiming for an image / sound quality similar to the SRB launcher demo video currently available in my LiveVideo page): of course that people will be able to have a better sound when playing with the released addon.

António

PS: MeshWizard: yes, I know about it (have included the reference in my development links page). I build my models with the correct scale and take the needed numbers from the 3D editor. MeshWizard can still be handy for other stuff (it would be great if could have the true material colours and texture representation).
my pics @ flickr

Offline Zachstar

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RE: "Direct" Alternative
« Reply #117 on: 09/24/2006 02:31 AM »

Thanks SimC for the updates!

---Good News for TeamTalk Users!---

The Orbiter TeamTalk Server is now online! This means now that you can connect and talk to SimC (Or anyone else) while he is showing of his awesome Direct Addon.

 
So get TeamTalk http://www.bearware.dk/ and be ready! I hope to see some of yall Orbiter (And SimC) Fans connecting!

---Connect Details---

Browser Direct  ;) connect link: tt://bigdas.no-ip.org (Note: Must have TeamTalk http://www.bearware.dk/  for this link to work. Just Click and it will open TeamTalk to connect to the server.)

Address: bigdas.no-ip.org

Ports: Use the default TeamTalk ports

No Password


-------------

Ok SimC you are all set for Voice comms! so I shall be looking forward to when you shall do a live demo!

Thanks Alot SimC! 


Offline Zachstar

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RE: "Direct" Alternative
« Reply #118 on: 09/24/2006 04:10 AM »
---Where are you kraisee?---

I have not seen you post in this topic in a dogs age! Any updates of your developments of this great idea?

Also: Will we see you during the live demo of the add-on?

---Shock Cones---
SimC I checked out orbithangar and found an impressive Shock cone texture http://www.orbithangar.com/searchid.php?ID=937 perhaps it can be adapted as well for lower atmosphere flight?

Offline simcosmos

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RE: "Direct" Alternative
« Reply #119 on: 09/24/2006 10:34 AM »
More quick answers:

TeamTalk Server: thanks! One less thing for me to worry about ("just" need to keep an eye in the telemetry server and another in the launcher / spacecraft controls now).

Exhausts: yep, I saw those and a few others too ;) For now will just stay with the current dds and try to pay more attention to other items. Will go back to the exhausts subject in a later development moment.

Flight Tests / WIP: due to the thunderstorms I got a bit behind the schedule for this weekend… In the moment I write these lines, the pad and EDS are not ready for export. Meanwhile, fixed a few visual glitches and implemented another version of an automatic guidance, this time trying to follow one *STSish* ascent trajectory by using the GPC MFD as rough reference for the trajectory tweaks.

Live Demo(?): not sure (due to weather constraints for a safe PC utilization) but I might try a live demo at +/- 16:30 or 17:00 GMT of today (24th September). Handy link: http://www.worldtimezone.com/index24.html .

Again: not sure if we have a GO for a live test today: if not, we always have the next weekend :)

António

PS: Zach, as far as I know (from a post in these forums >> Direct Pads thread), Ross is in *away mode* during this weekend (not expected to have computers / Internet around).
my pics @ flickr

Offline Zachstar

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RE: "Direct" Alternative
« Reply #120 on: 09/24/2006 06:44 PM »
Hello people!

We just had an amazing demo by SimC! Using his livepics page and TeamTalk in order to tell us about the stuff. Lots of interesting facts and issue notes were talked about during the flight. And the fact that he used STS sounds to help build the experience was amazing!

Also he gave us a great tour of all his "toys" Amazing stuff he has!

The next time he plans a live demo I do hope you will join us in the TeamTalk server! Till then good luck!

Image of "Direct's" launch attached.

Offline rumble

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Re: "Direct" Alternative
« Reply #121 on: 09/24/2006 07:18 PM »
Rats!  I missed it.  Is it difficult to do a video capture of a demo?  That would be super cool...  Doesn't need to be produced or narrated or anything.  Just video/audio capture of a demo running...

Offline Zachstar

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RE: "Direct" Alternative
« Reply #122 on: 09/24/2006 08:11 PM »
SimC was talking about making a video of it so I guess no worries.

But in the future I still prefer the Live Demos with TeamTalk.

Offline kraisee

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RE: "Direct" Alternative
« Reply #123 on: 09/25/2006 09:00 PM »
Quote
Zachstar - 23/9/2006  11:53 PM

---Where are you kraisee?---

I have not seen you post in this topic in a dogs age! Any updates of your developments of this great idea?

Also: Will we see you during the live demo of the add-on?

I was away for my birthday vacation with my better half.   I'm back now and fascinated to hear more about António's demo.

I'm going to be doing a lot of work over the next few days catching up with stuff for my company, but I'll also be updating the Direct info gradually at the same time.   So watch for updates.


*** António:   The EDS for Direct is not the same as the EDS used on the ESAS CaLV.

The calculations I've posted so far (94.4mT to LEO + EDS) assumes the same ESAS EDS is used, just with a single J-2 (and associated plumbing & t. structure removed also, reducing the overall mass by ~3,000Kg (~6,600lb)).   But on "Direct", the EDS phase of the ascent requires only 76,839Kg (169,402lb) of propellant to reach its 100x160nm initial orbit, compared to 120,061Kg (264,690lb) used during a CaLV flight to reach just 30x100nm.

This means smaller tanks will be required than the ESAS specification. Combined with a reduction to just one J-2 engine, reduces the dry mass considerably.   All my figures continue to assume 19mT for the dry mass, although I believe that could drop further to ~16-17mT.   This difference would translate 1:1 as an increase in final payload capacity above 94.4mT :)

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" Alternative
« Reply #124 on: 09/27/2006 11:53 PM »
I see by António's LivePic, that he's been up to some more on Direct in the last few days :)

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

Offline Zachstar

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RE: "Direct" Alternative
« Reply #125 on: 09/29/2006 06:22 AM »
Actually that was a pic from some test flight after the live demo ended. That was last sunday.

But it is friday so hopefully we get to see some magic soon!

Offline simcosmos

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RE: "Direct" Alternative
« Reply #126 on: 09/29/2006 09:07 AM »
Yep, you are correct Zach: the image currently loaded in the LivePics page - 20060924 timestamp, will soon move it to the flickr photo set - was from last weekend. I usually run a quick and extra Orbiter session, in the very end, just to upload a final beauty screenshot.

For this weekend will try to complete the goals left behind: launch pad and Direct variant with EDS alpha implementations and files / directory / documentation cleaning operations, all vital to start preparing a first public version or, at least, some private demo(s).

Will also try to produce a demo video but, if having to choose, will prefer to spend time with the 3D / Image editor and configuration files: the video will then look much better.


Talking about configurations and tweaks: Ross, I have a few comments / questions. Perhaps it would be nice if we could arrange one of those MSN meetings during this weekend to talk about stuff related with ascent trajectory options and also about some specific mass numbers (will need a more detailed sub-division of allocated mass for a few of the launcher components).


Moving on: next LivePics image should either show my first interpretation of the Direct EDS or, before that, perhaps will show the utilization of Direct's 3D and texture upgrades being used to produce a basic variant of an *ESAS CaLV* (that will be used on my other NASA VSE SC addon).

Regarding a LiveTest for this weekend: it will depend on how things go. Like mentioned above, if having to choose, I prefer to hold a bit the *public relations* updates (images / video, etc) and concentrate in some delayed stuff (for Direct and for other virtual projects).

And I think it is all for now, work in progress,

António
my pics @ flickr

Offline Zachstar

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RE: "Direct" Alternative
« Reply #127 on: 10/01/2006 07:24 AM »
Justed checked the Flickr page! It's a Mars-OZ party!! Nice work!!

----------------------

On a side note I noticed you are working on the ESAS VSE style Cargo Launcher Ares V. I am curious if you might allow Francisdrake to use it in order to improve his CEV addon? I surely hope so.

He had indicated to me in an email last july that he may return to addon dev in the fall. This will be supremely aided if you may be willing to provide mesh sources for the Ares V. Matter of fact it will make things tons easier by just open sourcing your meshes under the Artistic License. I have uploaded a TXT version of it for easy inclusion in any zip on my webspace.  http://test.virtualunitedairlines.net/Ref/OSIArtisticLicense.txt

I understand that you will likely also want to make a version in multistage. A version in Multistage will be fine until Franz returns. However frankly a DLL can normally outperform a Multistage version. Will hope you will consider the open source path.

---------------------

Now back to direct. Will be maybe be able to see a livepic of the smaller EDS today? Or will that kind of stuff have to wait till next weekend? I guess it matters little when im drooling over all this Mars OZ stuff.   ;)

THANKS! for the continued efforts!!

Offline kraisee

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RE: "Direct" Alternative
« Reply #128 on: 10/01/2006 05:21 PM »
I haven't had any chance to log on this weekend until now.   Even then, I've only got about an hour.

Let me know what you're after António, either here or by e-mail.   I have attached a lot of the info here.


Direct:
=======

Booster Stage:
==============               
                  
Standard 4-segment Reusable SRB:                  
Number of SRB's:      2.00               
Isp (SL):         237.00      sec      
Isp (vac):         268.00      sec         
Average Thrust (each):      1,086,353.73   kg   2,395,000.00   lb   10,657,130.06   N
Maximum Thrust (each):      1,511,097.62   kg   3,331,400.00   lb   14,823,867.68   N
                  
Max Action Time:      123.70   sec            

Total Average Thrust:      2,172,707.45   kg   4,790,000.00   lb   21,314,260.12   N
Total Maximum Thrust:      3,022,195.25   kg   6,662,800.00   lb   29,647,735.36   N
Total Propellant Mass:      1,002,934.46   kg   2,211,092.00   lb      
Total Burnout Mass:      175,208.22   kg   386,268.00   lb      
                  
Total Stage GLOW:      1,178,142.68   kg   2,597,360.00   lb      


Main Stage Configuration:
=========================                  
                  
Number of Required Engines:   2.00               
Number of Redundant Engines:   0.00               
Total Number of Engines:   2.00               
Mission Power Level:      100.00      %            
                  
RS-68 Regen (est):                  
Isp (SL):         383.25               
Isp (vac):         441.00               
Average Thrust @ 100% (each):   309,576.79   kg   682,500.00   lb   3,036,948.34   N
Maximum Thrust @ 100% (each):   354,697.35   kg   781,973.80   lb   3,479,581.00   N
Engine Mass:         7,260.00   kg   16,005.56   lb      
                  
Total Engine Mass:      14,520.00   kg   32,011.12   lb
Support Systems Mass:      3,258.81   kg   7,184.45   lb
Total MPS Mass:         17,778.81   kg   39,195.57   lb

Primary Body Structure Mass:   33,626.98   kg   74,134.80   lb   
Secondary Structures Mass:   1,237.44   kg   2,728.08   lb   
Total Structure Mass:      34,864.42   kg   76,862.88   lb      
                  
Separation Systems:      1,273.03   kg   2,806.56   lb   
TPS:            187.46      kg   413.28      lb
TCS:            1,754.75   kg   3,868.56   lb   
Power (Electrical):      954.29      kg   2,103.84   lb   
Power (Hydraulic):      589.16      kg   1,298.88   lb   
Avionics:         303.91      kg   670.00      lb      
Miscellaneous:         259.91      kg   573.00      lb      
Ancillary Systems Mass:      5,322.51   kg   11,734.12   lb      
                  
Total Dry Mass Without Growth:   57,965.73   kg   127,792.57   lb      
                  
Dry Mass Growth Allowance:   4,707.31   kg   10,377.84   lb   
                  
Total Dry Mass With Growth:   62,673.04   kg   138,170.40   lb      
                  
Residuals Mass:         5,975.64   kg   13,174.04   lb   
eserves Mass:         1,190.76   kg   2,625.17   lb   
In Flight Losses Mass:      93.88      kg   206.98      lb
Total Surplus Propellant Mass:   7,260.29   kg   16,006.19   lb      
                  
BURNOUT MASS:         69,933.33   kg   154,176.59   lb      
                  
Main Ascent Propellant Mass:   793,856.57   kg   1,750,154.15   lb   
Engine Purge Helium Mass:   89.94      kg   198.29      lb
                  
TOTAL STAGE GLOW:      863,879.84   kg   1,904,529.03   lb

Total Average Thrust:      619,153.59   kg   1,365,000.00   lb   6,073,896.67   N
Total Maximum Thrust:      709,394.70   kg   1,563,947.60   lb   6,959,162.01   N

Action Time:         495.00      sec


Upper Stage Configuration (Optional Stage):
===========================================            
                  
Number of Required Engines:   1.00               
Number of Redundant Engines:   0.00               
Total Number of Engines:   1.00               
                  
J-2X (May 2006 spec, NOT the expected 294K lb thrust variant):                  
Isp (SL):         345      sec            
Isp (vac):         448      sec            
Average Thrust @ 100% (each):   116,119.65   kg   256,000.00   lb   1,139,133.74   N
Maximum Thrust @ 100% (each):   132,902.56   kg   273,500.00   lb   1,303,774.16   N
Mission Power Level:      100.00      %            

Total Engine Mass:      1,400.00   kg   3,086.47   lb
Support Systems Mass:      2,934.32   kg   6,469.06   lb
Total MPS Mass:         4,334.32   kg   9,555.53   lb
            
Primary Body Structure Mass:   5,687.54   kg   12,538.88   lb
Secondary Structures Mass:   707.17      kg   1,559.04   lb
Total Structure Mass:      6,394.71   kg   14,097.92   lb
            
Separation Systems:      90.26      kg   199.00      lb
TPS:            143.79      kg   317.00      lb
TCS:            672.22      kg   1,482.00   lb
Power (Electrical):      640.93      kg   1,413.00   lb
Power (Hydraulic):      183.25      kg   404.00      lb
Avionics:         195.04      kg   430.00      lb
Miscellaneous:         59.42      kg   131.00      lb
Total Ancillary Systems Mass:   1,984.92   kg   4,376.00   lb
            
Total Dry Mass Without Growth:   12,713.95   kg   28,029.45   lb
            
Dry Mass Growth Allowance:   1,632.48   kg   3,599.00   lb
            
Total Dry Mass With Growth:   14,346.42   kg   31,628.45   lb
            
Residuals Mass:         2,407.90   kg   5,308.50   lb
Reserves Mass:         284.63      kg   627.50      lb
In Flight Losses Mass:      26.76      kg   59.00      lb
Total Propellant Mass:      2,719.29   kg   5,995.00   lb
            
BURNOUT MASS:         17,065.71   kg   37,623.45   lb
            
Main Ascent Propellant Mass:   76,839.27   kg   169,401.60   lb
Engine Purge Helium Mass:   23.59      kg   52.00      lb
            
TOTAL STAGE GLOW:      93,928.57   kg   207,077.05   lb

Prop. Used during Launch Phase:   76,839.27   kg   169,401.60   lb
            
Action Time:         259.00      sec      
            

Payload Configuration without EDS:
==================================

To 100x160nm 28.5deg Orbit:

Payload Shroud:         4,772.70   kg   10,522.00   lb
Payload:         75,628.17   kg   166,731.57   lb


Payload Configuration with EDS:
===============================

To 100x160nm 28.5deg Orbit:

Payload Shroud:         4,772.70   kg   10,522.00   lb
Payload:         94,428.34   kg   208,178.86   lb



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" Alternative
« Reply #129 on: 10/01/2006 06:01 PM »
And here are some diagrams of the trajectory for the Direct without EDS:
"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" Alternative
« Reply #130 on: 10/05/2006 08:12 PM »
Been busy this week, but I'm back now.   Am working to update the budget, pad design and optimising the payloads further over the comming days.   Looks like performance numbers are actually going to climb slightly more :)

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

Offline simcosmos

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RE: "Direct" Alternative
« Reply #131 on: 10/06/2006 09:54 AM »
And we are in that moment of the week that is best for me to give a few answers / extra updates

Quote
Zachstar - 1/10/2006  8:07 AM

Justed checked the Flickr page! It's a Mars-OZ party!! Nice work!!


Thanks: yes, should have more Mars-Oz previews in the next weeks.


Quote
Zachstar - 1/10/2006  8:07 AM

On a side note I noticed you are working on the ESAS VSE style Cargo Launcher Ares V. I am curious if you might allow Francisdrake to use it in order to improve his CEV addon? I surely hope so.

He had indicated to me in an email last july that he may return to addon dev in the fall. This will be supremely aided if you may be willing to provide mesh sources for the Ares V. Matter of fact it will make things tons easier by just open sourcing your meshes under the Artistic License. I have uploaded a TXT version of it for easy inclusion in any zip on my webspace.  http://test.virtualunitedairlines.net/Ref/OSIArtisticLicense.txt

I understand that you will likely also want to make a version in multistage. A version in Multistage will be fine until Franz returns. However frankly a DLL can normally outperform a Multistage version. Will hope you will consider the open source path.

Will not go open source regarding my models because of a number of reasons. However this does not mean that I do not accept c++ contributes or that I do not provide my models for specific projects as long as things are properly talked about (and yes, I already thought in the past about providing my launchers to Francisdrake's specific ESAS addon but we never really discussed that, maybe in a later moment).


Quote
Zachstar - 1/10/2006  8:07 AM
Now back to direct. Will be maybe be able to see a livepic of the smaller EDS today? Or will that kind of stuff have to wait till next weekend? I guess it matters little when im drooling over all this Mars OZ stuff.   ;)

Hummm, a little late answer but here it goes anyway: I have the old ESAS EDS on the top of Direct launcher but still haven't 100% produced / integrated the version for Direct.

Meanwhile I decided to focus in the launch pad + MLP implementation: these are still early alphas (3D and textures not quite ready) that I imported yesterday because was really getting tired about launching Direct from Orbiter's default pads :)

Direct's pad / MLP design will be tweaked in a later moment but, for now, their import also served three important goals:

  • to prepare the directory structure and all required files for Direct's custom Solar System definition


  • to properly place the pads (+ fixed tower) in the right spots; same for the MLP and support tower (MLP defined with a separated and very simple cfg so that it can be easily removed from the scenario)


  • perhaps the preparation of a clumsy demo video, anxiously expected by some fellow readers ;)



Related with Direct eye-candy: Orbiter had a new patch and I have been playing with attachment points, the new Atlantis, multistage2.dll and payload definitions via scenario (with Atlantis being fully functional during launch with multistage automatic guidance and cool SRB smoke). McWgogs also kindly gave me permission to use his textures or derived work in my projects. This to say that a few of that eye-candy work that I have been doing with STS will be also used with Direct.


Ross: just sent a new email in your way, thanks again for the info (will prepare pics during the afternoon)


António

PS: not sure if there will be a LiveTest this weekend. I will probably meet online with Ross to talk about several details. Maybe we can prepare another funny live event, do not know(?) Work in progress...

my pics @ flickr

Offline kraisee

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Re: "Direct" Alternative
« Reply #132 on: 10/06/2006 09:26 PM »
Posted these over in the other thread.   Thought I should link them here too :)

http://65.33.118.71/Public/Direct/NASA_DirectSDLV_DEVWIP20061006simcosmos_00.jpg">

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline kraisee

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RE: "Direct" Alternative
« Reply #133 on: 10/09/2006 07:01 AM »
For anyone interested, I just worked out the logical growth option for DIRECT...

What happens if you upgrade it to 5-segs?

Optimizing the design, you also need to Barrel Stretch the core by 31%, and the best performance came from adding a third RS-68 Regen.

Basic CLV performance climbed to 94.5mT to 60x160nm 28.5deg, and with an optimized EDS (32.8% increased capacity, 3mT heavier tanking), the performance climbs to higher than Ares-V's:   137.5mT to 60x160nm.

And none of that costs more than Ares-I and Ares-V together, just removes the near-term costs, and keeps annual fixed costs to a single LV program instead of two.   Saves about $1Bn per year...

R.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline rumble

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Re: "Direct" Alternative
« Reply #134 on: 10/09/2006 01:07 PM »
What do max g-forces grow to without EDS?

Designs will need to be careful to avoid/minimize pogo in that center RS-68.  Ares V will have the same issue to engineer around.

Offline kraisee

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Re: "Direct" Alternative
« Reply #135 on: 10/09/2006 02:23 PM »
Quote
rumble - 9/10/2006  8:50 AM

What do max g-forces grow to without EDS?

Designs will need to be careful to avoid/minimize pogo in that center RS-68.  Ares V will have the same issue to engineer around.

Rumble, below are the full trajectory graphs for this "Growth Option" DIRECT CLV.   As you'll see, it's a 4g max profile.   Max-q dynamic pressure climbes to 28825 pascals, which is 602lb/ft2 without throttling the mains at all.

This all still needs to be run through something like POST to officially confirm the findings of course...

And yes, pogo-suppression hardware is potentially required.   I've already been toying with the idea of sacrificing about 9mT of capacity in a trade for a fourth RS-68R with all it's associated plumbing.   That would offer 100% engine-out capacity from T-0 to MECO and locate all the engines away from the centerline.   It's just one of many potential solutions if the design has any issues like that.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline kraisee

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RE: "Direct" Alternative
« Reply #136 on: 10/09/2006 07:26 PM »
António has expertly prepared his first 5 minute video demonstrating the DIRECT CLV's launch.

It's 11.4Mb in size, and hosted on a fairly slow server, so please be patient.

I think it looks wonderful, but I'm most definately biased ;)

Enjoy!

Primary Site: http://65.33.118.71/Public/Direct/NASA_DirectSDLV_20061008wip_simcosmos.WMV

Mirror Site: http://simcosmos.planetaclix.pt/temp/NASA_DirectSDLV_20061008wip_simcosmos.WMV

Spec is a basic 25mT Orion CEV flight to ISS, with a 45mT mass simulator 'disc' inside the SLA, which never detatches from the Core stage (you can see it after CEV sep).

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline simcosmos

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Re: "Direct" Alternative
« Reply #137 on: 10/09/2006 09:34 PM »
-------------------------------------------------------------------------------------------------------------------------------------
!EDIT: Mirror of Direct's demo / wip video (October2006) moved to:
http://simcosmos.planetaclix.pt/temp/Direct/NASA_DirectSDLV_20061008wip_simcosmos.WMV

-------------------------------------------------------------------------------------------------------------------------------------

My pleasure Ross ;)

Just a small note to all downloading and having a look at the video:

Fellow nasaspaceflight reader,

Please do not pay too much attention to the details. Despite the video had some evident production care when regarding the capture and editing of the sequences + sound this is a demo of the work in progress (read: weekends progress). This to say that people should look at this as when looking at the development pictures posted in my flickr space or LivePics.

Being more specific, any less correct stuff going on in this demo video is probably caused by one of the following 3 reasons:

  • still very early addon implementation and lots of tweaks / tests / other stuff to do

  • some limitations of what can be done also exist (these can be removed with extra time, updated tools and/or new collaborators)

  • my PC is starting to get old (PIIIat600Mhz, 384SDRAM, GeForceFX5200 is not exactly the best configuration for things such as to record video of development files without messing up with things like the automatic guidance, etc)



This little remark done, I hope people have fun with the video: the interested will be able to have this toy at home and   "play" with it.. one day :)

Despite what I wrote above, feel free to make any comment / suggestion / question, if you wish

Thanks,
António

PS: please, just do not ask for release dates or I will be forced to answer "Whenever is ready" or, the also famous in some circles, "On Tuesday" (and then you will have to keep an eye on every Tuesdays of the year).
my pics @ flickr

Offline Mark Dave

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Re: "Direct" Alternative
« Reply #138 on: 10/10/2006 07:07 PM »
I found this comparison pic, even though it's for scale modelling, it may as well fit in here http://www.ninfinger.org/~sven/models/vault2006/Ares1%20and%20V%20Dimensions%20at%20144%20scale.jpg

I just got a book with bonus dvd called Saturn by Apogee books that explains alot on the Saturn V. I was wondering why not use similar engines for the core of Ares V? The F-1?

Offline Jim

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Re: "Direct" Alternative
« Reply #139 on: 10/10/2006 07:11 PM »
They don't exist anymore

Offline Mark Dave

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Re: "Direct" Alternative
« Reply #140 on: 10/10/2006 07:45 PM »
I know. My question was why not use engines just as powerful for AresV?

Offline Jim

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Re: "Direct" Alternative
« Reply #141 on: 10/10/2006 11:04 PM »
Because the RS-68 exists and therefore cheaper.  No development program

Offline meiza

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Re: "Direct" Alternative
« Reply #142 on: 10/10/2006 11:56 PM »
In a way, the shuttle solids are F-1:s successors, and provide the low-isp high-t/w bulk thrust for the early flight.

Offline kraisee

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Re: "Direct" Alternative
« Reply #143 on: 10/11/2006 09:30 PM »
Meiza, its a bit of a stretch, but I know what you mean.

They do the same basic job, getting the second stage up to speed and altitude to do it's work, but they allow the second stage to be lit on the ground - which ought to be safer.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline pierogoletto

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Re: "Direct" Alternative
« Reply #144 on: 10/12/2006 09:50 PM »
Quote
JIS - 11/9/2006  7:45 PM


I think there is no point for NASA to develop manned vehicle for LEO.
Maybe even more important is to have capability to deliver some significant cargo to the Moon, libration points, close asteroids or Mars in one shoot. And its Ares V.  


Although LEO or Moon may be stepping stones to go beyond, that's not at all the base idea of ESAS.

Piero Giuseppe Goletto

Offline kraisee

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RE: "Direct" Alternative
« Reply #145 on: 10/20/2006 07:14 PM »
A question for someone more familiar with LM's proposals (maybe Kayla?), but I'm wondering about the performance benefits of using a "Centaur approach" to making an EDS...

In short, the Centaur basically works by being a very light-weight stage, which only flies in space.   Because it doesn't need hardware to support atmospheric flight, it can be built down in mass to the barest possible minimum.

Normally a Centaur stage will fly inside the payload shroud to provide it with protection during the atmospheric phase of a launch.

Now, obviously DIRECT would need something plenty bigger than an existing Centaur, but the same approach might result in performance benefits.

What I'm really asking is this:   If there were something like a 7.8m diameter Centaur, with a single J-2X engine, fitted inside the DIRECT's 8.4m diameter payload fairing, what sort of benefits could that offer over the "aero-EDS" approach currently being proposed?

Currently the aero-EDS increases performance from 70.9mT to 98.2mT to 60x160nm 28.5deg insertion orbit.   Would this approach be able to improve performance significantly?

TIA for any explanations.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline Jim

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Re: "Direct" Alternative
« Reply #146 on: 10/20/2006 07:54 PM »
The Centaur is only in the fairing because it is only 10' in diameter and the spacecraft is bigger, not because it needs protection.  The Centaur for the 4m fairing  (which is outside) is the same as the one inside the 5m fairing.    Atlas did this to keep the number of configurations down (only one is needed).  A fatter Centaur just like the Atlas V Phase two options, using the same diameter as the booster is better.  It has less surface area and the equivilent fairing is shorter and therefore lighter.   Also the ground ops is easier and less with less work with the wider stage (don't have the extra steps of encapsulating the stage)

Offline kraisee

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Re: "Direct" Alternative
« Reply #147 on: 10/21/2006 05:12 AM »
Jim,
   Little wonder then why I was continually scratching my head to figure out why it wasn't being looked at ;)

Ross.

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Offline rumble

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Re: "Direct" Alternative
« Reply #148 on: 10/21/2006 10:00 PM »
Ok.  Let's combine them then.

Would the centaur design transfer to a stage as wide as, say, the ET?  If the engine used was a J-2X instead of an RL-10, would it still be a centaur?

It makes some sense to me for LM to build the US/EDS for DIRECT and just use a J-2X as the power plant instead of a cluster of RL-10's or RL-60's.

How would a centaur-based design differ from something MSFC would create?

Offline Jim

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Re: "Direct" Alternative
« Reply #149 on: 10/21/2006 10:11 PM »
EDS is only bigger than the Centaur or the D-IV second stage.  Either design can be used

Offline simcosmos

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RE: "Direct" Alternative
« Reply #150 on: 10/22/2006 10:32 AM »
Yes, that is my goal when making the EDS for NASA VSE SC and Direct SDLV Orbiter addons ;)

From my flickr photo set (please click image to directly load the specific EDS page / description):

EDSwip - simcosmos


The above EDS still needs work in several components and, for Direct use, I might still have to change its dimensions (to accommodate extra propellants).

I used Apollo / Centaur and also First Lunar Outpost images as inspiration to model it:

Already widely known in these forums, but here goes a link for a page where people can read more about Lockheed-Martin studies regarding Centaur Extensibility to Long-Duration In-Space Applications


Specific FLO image that used as inspiration for the external look (although it seems that its EDS design would not have a common bulkhead):
http://aerospacescholars.jsc.nasa.gov/HAS/cirr/Images/flo2.jpg

See:
http://www.abo.fi/~mlindroo/Station/Slides/sld051f.htm
http://www.astronautix.com/craft/firtpost.htm


Also used a few pre-ESAS images, like:
New Cryo US for CaLV
New Cryo US for CLV

(both from SDLV/CEV - JULY AIAA Joint Propulsion Conference Document)


To end, a clumsy photo where I'm playing with the EDS internal layout, just for *rough* visualisation purposes; it might not be 100% correct. Just went to one of the previous pictures and made a bit of copy+paste to size the tanks for a given amount of hydrogen / oxygen, please see attachment)

António

 
my pics @ flickr

Offline rumble

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Re: "Direct" Alternative
« Reply #151 on: 10/22/2006 04:01 PM »
Excellent stuff.  I think the common bulkhead design makes all kinds of sense on an EDS for weight AND cryo storage purposes.

Concern with your last image on the page:  The RCS nozzles look dangerously close to the interstage...  I know you're just working on concepts (work in progress), but I see it being possible the interstage could slide off "less than perfectly" and damage one or more of those nozzles, and possibly that entire RCS structure.

Thanks for sharing all your visual work...

Offline simcosmos

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Re: "Direct" Alternative
« Reply #152 on: 10/22/2006 04:12 PM »
Thanks,

Yes, still playing with RCS (and other parts :) ). There are about 2 or 3 options for the RCS:

a) in the bottom of the EDS, +/- like in the previous pictures (but still have to fine tune a good position / attachment method when thinking about control and clearances)
b) internal, I mean, something similar to some of the recent CLV representations  (RCS for upper stage / interstage)
c) external pods, like in Apollo

All approaches should have its advantages and disadvantages: I would prefer to make them in the bottom and/or somehow *internal* (at least from a purely cosmetic point of view :) ). Still have to better research about the subject as well how it is (or would be) done in Centaur derived hardware.

António
my pics @ flickr

Offline kraisee

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Re: "Direct" Alternative
« Reply #153 on: 10/23/2006 01:21 AM »
I would suggest integrating them into an 'aft skirt' area.   There will have to be one anyway for the lower umbilical connections to be attached to.   I would use the basic design from the Ares-V myself.

Can you calculate the real-world volumes of the individual tanks?

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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Offline simcosmos

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Re: "Direct" Alternative
« Reply #154 on: 10/23/2006 09:30 AM »
Quote
kraisee - 23/10/2006  2:04 AM

I would suggest integrating them into an 'aft skirt' area.   There will have to be one anyway for the lower umbilical connections to be attached to.   I would use the basic design from the Ares-V myself.

Will try to introduce some alterations in that regard (must first study umbilical connections).

Quote
kraisee - 23/10/2006  2:04 AM
Can you calculate the real-world volumes of the individual tanks?

It is a bit harder for common bulkhead designs, much easier if assuming separated tanks: for common bulkhead I kind of *visually* extrapolate from separated tanks volumes / shapes. The above EDS is 8.4m width (other dimensions can be known by comparison, short in time now to take the dims from the 3D model) for a total propellant quantity (LH2+LO2) of about 105.2mt / 106mt or so. Still need to do some flight tests / math. Depending of a few hardware / mission design assumptions Direct might (or not) need a bigger EDS (will also implement something like the "official" EDS Direct numbers and something in-between and then compare results between the 3 versions, maybe next weekend)

António
my pics @ flickr

Offline publiusr

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Re: "Direct" Alternative
« Reply #155 on: 12/22/2006 07:43 PM »
Your artwork just keeps getting better and better.

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