Author Topic: "Direct" Alternative  (Read 73719 times)

Offline 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 »
Quote
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.
"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 #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.
"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 #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.
"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 #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.
"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 #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.

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

Offline mong'

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