Author Topic: DIRECT v3.0 - Thread 1  (Read 714075 times)

Offline kraisee

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DIRECT v3.0 - Thread 1
« on: 06/01/2009 03:45 PM »
Now that DIRECT v3.0 has been shown at ISDC, it is time to open a specific thread for appropriate discussions here.

Over the course of today I will try to upload a variety of material to kick this thread off properly.

I will leave the v2.0 thread open for any continued discussion about the older variant of DIRECT, but this should now become the new primary discussion thread.


I will start this thread by uploading the latest animation sequences.

Ross.
« Last Edit: 06/01/2009 03:46 PM by kraisee »
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Offline Crispy

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Re: DIRECT v3.0 - Thread 1
« Reply #1 on: 06/01/2009 03:48 PM »

Offline Alpha Control

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Re: DIRECT v3.0 - Thread 1
« Reply #2 on: 06/01/2009 03:48 PM »
Great to be here, and congratulations on the new animation. Can't wait to get home and see it.  Chuck, I beat you to the thread! :)

Edit: so much for being first!  :)
« Last Edit: 06/01/2009 03:49 PM by Alpha Control »
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Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #3 on: 06/01/2009 03:49 PM »
MPEG 4 version.
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Offline Danny Dot

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Re: DIRECT v3.0 - Thread 1
« Reply #4 on: 06/01/2009 03:51 PM »
Your video says "LOX tank extension".  This implies a bigger mod than you might be doing.  Are you just changing the shape of the end of the tank?

You might make a note of this for your next release.

I would also be interested in the total weight on the pad of Shuttle and Jupiter 130.  Given they have the same engines and prop, the gross weight on the pad is probably the same.  This might be an easy way to show the performance of Jupiter 130 does NOT defy the laws of physics.

Danny Deger
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Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #5 on: 06/01/2009 03:52 PM »
WMV version.
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Offline Alpha Control

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Re: DIRECT v3.0 - Thread 1
« Reply #6 on: 06/01/2009 03:52 PM »
Ross, thanks for the link to the "The Space Show". Looking forward to tuning in tomorrow night.
« Last Edit: 06/01/2009 03:53 PM by Alpha Control »
Space launches attended:
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Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #7 on: 06/01/2009 03:57 PM »
Your video says "LOX tank extension".  This implies a bigger mod than you might be doing.  Are you just changing the shape of the end of the tank?

You might make a note of this for your next release.

It refers to the fact that the "barrel" section of the LOX tank is "extended" instead of using the Ogive section.


Quote
I would also be interested in the total weight on the pad of Shuttle and Jupiter 130.  Given they have the same engines and prop, the gross weight on the pad is probably the same.  This might be an easy way to show the performance of Jupiter 130 does NOT defy the laws of physics.

They're similar, but Jupiter is actually slightly lower.   We've done that because we are including extra margins.   While Shuttle is a mature system, Jupiter will be a new one and we would rather have greater margin, at least until Jupiter also matures.

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

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Re: DIRECT v3.0 - Thread 1
« Reply #8 on: 06/01/2009 03:59 PM »
Is there a summary of updates somewhere from 2.0 to 3.0?

Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #9 on: 06/01/2009 03:59 PM »
Here are some more "treats" from Philip...

Enjoy,

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

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Re: DIRECT v3.0 - Thread 1
« Reply #10 on: 06/01/2009 04:04 PM »
Love the detail in those renders. Very nice :)

Offline clongton

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Re: DIRECT v3.0 - Thread 1
« Reply #11 on: 06/01/2009 04:07 PM »
I never tire of watching that video
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline dougkeenan

Re: DIRECT v3.0 - Thread 1
« Reply #12 on: 06/01/2009 04:07 PM »
Wallpaper, yum!

Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #13 on: 06/01/2009 04:09 PM »
Is there a summary of updates somewhere from 2.0 to 3.0?

It's pretty simple really:

RS-68 main engines swapped for SSME's.

The higher efficiency of the SSME's on the Core allow for the Upper Stage to be made quite a bit smaller.

A smaller Upper Stage means that other engine choices can also be considered, like RL-10 and RL-60, not just J-2X.

While we aren't specifying any "final decision" on the Upper Stage engine selection yet, we are strongly recommending an RL-10B-2 solution be considered because that would mean that all the engines (4-seg SRB's, SSME's and RL-10B-2's) are all essentially "off the shelf".

That results in removing all of the highly expensive engine development programs which are usually the determining factor in the development schedule too.


In a nutshell, DIRECT v3.0 offers a solution needing no engine developments at all for supporting all of the ISS and Lunar objectives.


From there, the architecture is designed to fit that capability while providing nice healthy margins in all areas; performance, budget and schedule.

Ross.
« Last Edit: 06/01/2009 04:12 PM by kraisee »
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Offline ar-phanad

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Re: DIRECT v3.0 - Thread 1
« Reply #14 on: 06/01/2009 04:11 PM »
Fantastic, Ross. Thank you.

Offline renclod

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Re: DIRECT v3.0 - Thread 1
« Reply #15 on: 06/01/2009 04:11 PM »
Ross, very nice presentation.

Why is the "ET 8.4m Forward Skirt" there ? Is it a structural member to relieve the LOX tank from loads ? Why ? What are the implications ?
Is the LOX tank not a structural member ? (does not carry loads ?) Why ?

TIA.

 



Offline Alpha Control

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Re: DIRECT v3.0 - Thread 1
« Reply #16 on: 06/01/2009 04:12 PM »
Beautiful images. The detailing is excellent, especially on the SSMEs and the EDS. They almost look like photos of an actual kit buildup.
Now where can I buy one? :)
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Offline Danny Dot

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Re: DIRECT v3.0 - Thread 1
« Reply #17 on: 06/01/2009 04:13 PM »
snip

They're similar, but Jupiter is actually slightly lower.   We've done that because we are including extra margins.   While Shuttle is a mature system, Jupiter will be a new one and we would rather have greater margin, at least until Jupiter also matures.

Ross.

You do need more margin because of the significant changes to structure and new structures to be developed.  I would add 20% margin to all new structure.  This would not include the whole ET, just the part of the ET that was new.   Maybe a direct comparison of Shuttle and Jupiter gross weights on the pad would be useful.  This is rocket science even a congressman/senator can understand. 

Danny Deger
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Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #18 on: 06/01/2009 04:13 PM »
The Fwd Skirt actually comes in along with the 'foam' which covers the rest of the LOX tank.   Its just a visual thing.   They could be separated, but we wanted to keep the video short.

Ross.
« Last Edit: 06/01/2009 04:26 PM by kraisee »
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Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #19 on: 06/01/2009 04:25 PM »
You do need more margin because of the significant changes to structure and new structures to be developed.  I would add 20% margin to all new structure.  This would not include the whole ET, just the part of the ET that was new.   Maybe a direct comparison of Shuttle and Jupiter gross weights on the pad would be useful.  This is rocket science even a congressman/senator can understand.

Depending on how much heritage each part has, we have between 10% and 20% structural margins for every sub-element of the Core Stage design.   The Thrust Structure and Fwd Skirts are all-new, so those elements have full 20% margins.   In comparison, the LH2 tank domes are *very* similar to Shuttle's, so we're only using 10% margins for those structures.

And that is all in addition to meeting the basic 1.4 FS requirement.

FYI:   A standard Jupiter-130 CLV heading for ISS has a GLOW of 2,057,232kg.   It lifts 66,980kg of useful payload to 100x100nmi, 51.6deg.   Assuming a 20,185kg Orion, that leaves 46,795kg for additional cargo -- roughly equivalent to 3 ISS-bound Shuttle payloads worth.

Ross.
« Last Edit: 06/01/2009 04:25 PM by kraisee »
"The meek shall inherit the Earth -- the rest of us will go to the stars"
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