Author Topic: Atlas V and Centaur Q&A  (Read 212206 times)

Offline Prober

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Re: Atlas V and Centaur Q&A
« Reply #660 on: 02/12/2016 02:16 AM »
Apparently they traded balloon tanks even against composite and it still came ahead. But first stage mass isn't really that critical. Atlas I/II was a different issue because it was a 1.5 stage design.
But given the fact that Vulcan will use Centaur and then ACES, my bet is on raw cost as primary consideration for core tanking. Which probably will mean Al 2219 with composite interstage on Delta IV tooling.


well I sure hope they have upgraded ACES from the material released.  It's real old and can be done alot cheaper, and faster out the door then that plan submitted. ::)
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Online rayleighscatter

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Re: Atlas V and Centaur Q&A
« Reply #661 on: 02/15/2016 02:23 PM »
I must sheepishly admit I couldn't figure this out on my own... Why does the 5m fairing cover the second stage when the 4m fairing doesn't?

Offline ugordan

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Re: Atlas V and Centaur Q&A
« Reply #662 on: 02/15/2016 02:29 PM »
I believe because Centaur itself can't handle aero loads of more than 3 SRBs or such a wide area as a 5 m fairing presents.

Offline Remes

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Re: Atlas V and Centaur Q&A
« Reply #663 on: 02/20/2016 11:06 AM »
Apparently they traded balloon tanks even against composite and it still came ahead. But first stage mass isn't really that critical. Atlas I/II was a different issue because it was a 1.5 stage design.
But given the fact that Vulcan will use Centaur and then ACES, my bet is on raw cost as primary consideration for core tanking. Which probably will mean Al 2219 with composite interstage on Delta IV tooling.

For the sake of completeness I provide two links here from George Sowers:
https://forum.nasaspaceflight.com/index.php?topic=37295.msg1361982#msg1361982
https://forum.nasaspaceflight.com/index.php?topic=37295.msg1358078#msg1358078

I agree, that first stage weight is not that critical for performance. I'm thinking more of cost and reliability. Less different processes, less different trainings needed for personnel, less different QA/test procedures, less different materials, ...

Of course, the reliability can be as high with more different materials/processes/..., but it comes at higher cost.

Also, Convair/GD had production down to a pretty high level of efficiency using tooling of that era, which included automated welding jigs.  They built 100+ Atlas stages in 1962.  I'm not sure that robotics would improve on that much.
There are some great pictures about the production process of Atlas on L2, but I couldn't find them.They showed people unrolling stainless steel coils manually. One person was ultrasounding the steel manually. My idea would be really a full automation and pervasive testing:
- Coil goes into machine
- unrolling and cutting is done automatically
- ultrausounding 100% automatically for material inspection (so the state of every single square inch/cm is absolutely known)
- if there are no people around, do 100% x-raying
- butt welding, spott welding, ... all is done automatically
- welding current is monitored continually (if two segments are welded, how is the distribution of currents to the different segments, what is the expected value, ...)
- Flir cameras monitor the heat distribution and compare it permanently to expected values
- before and after a segment is unrolled, small parts of the material are cut and automatically put in a testing machine which tests for tensile strength (applying force and measuring the stretching on a micrometer level and comparing it to expected values, checking the reversive and nonreversive areas)
- The machine could test tensile strength of the unrolled part which goes into the rocket in the reversive region
- Small parts could be grinded away (talking about micrograms) and putting it into a mass spectrometer, checking for material composition

All points would be fully automated and fully monitored. All structural parts are welded automatically (e.g. thrust structure, interstage attachment, ...)

The fixture where the tank is produced allows for a (modular, highly automated) container grabbing the stage and providing an automatic enclosure holding the whole tank. The containers are removed shortly before the start. All elements such as dome/bulkheads should be joined automatically. Looking at youtube videos the atlas tanks had (despite welding rigs) a lot of moving/aligning/... in its production process. Aligning would be done with lasers, lidar, etc.

I wonder, if the high level of testing would allow to break up the history tracking from ore to orbit. Allowing to purchase stock material and testing it for compliance without requiring the costly certification of suppliers and their suppliers and their....

Quote
At any rate, the predominant cost of the stages is in the engines and electronics.

If it works for tanks it should work also for engine parts. If I look at the tube design of an RL-10 I would immediately think of automatic the cutting, rolling, bending, welding, ... again with lots of testing which allows to use non space certified materials, but in the end having still the confidence that the material is perfectly fine.

Offline Jim

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Re: Atlas V and Centaur Q&A
« Reply #664 on: 02/20/2016 11:47 AM »

- before and after a segment is unrolled, small parts of the material are cut and automatically put in a testing machine which tests for tensile strength (applying force and measuring the stretching on a micrometer level and comparing it to expected values, checking the reversive and nonreversive areas)
- The machine could test tensile strength of the unrolled part which goes into the rocket in the reversive region
- Small parts could be grinded away (talking about micrograms) and putting it into a mass spectrometer, checking for material composition


I wonder, if the high level of testing would allow to break up the history tracking from ore to orbit. Allowing to purchase stock material and testing it for compliance without requiring the costly certification of suppliers and their suppliers and their....


No, because most that testing is destructive.  Testing is not going to be eliminated.  The aircraft industry still uses certified materials.

Offline Remes

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Re: Atlas V and Centaur Q&A
« Reply #665 on: 02/20/2016 12:48 PM »
No, because most that testing is destructive.  Testing is not going to be eliminated. 
My idea was:
- take the stainless steel roll and unroll 10cm from the coil, cut it, and test it destructively
- unroll 12m, test it nondestructively, ultrasonic, x-ray, testing for tensile strength withing the linear reversible region, weld it into the tank
- unroll 10cm and do again destructive testing
- also keep some specimen back, computer logs every force/deflection/..., laser scanner scan the final tank, etc

Quote
The aircraft industry still uses certified materials.
A long history of errors and failures have taught Space and Aerospace people not to make changes all the time. To pay utmost attention at any step and to test over and over again. That is currently the typical approach of e.g. the Ariane/Atlas/Delta and the track records speak for themselves. It's just a very costly process and technology has progressed.

Also the number of certified supplier who are really able to provide a gap free history is very limited. So there is not a really an open market competition. Given the high entry hurdles there is a small chance that new, more advanced companies enter the market.
« Last Edit: 02/20/2016 12:50 PM by Remes »

Offline Jim

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Re: Atlas V and Centaur Q&A
« Reply #666 on: 02/20/2016 01:41 PM »

- take the stainless steel roll and unroll 10cm from the coil, cut it, and test it destructively
- unroll 12m, test it nondestructively, ultrasonic, x-ray, testing for tensile strength withing the linear reversible region, weld it into the tank
- unroll 10cm and do again destructive testing
- also keep some specimen back, computer logs every force/deflection/..., laser scanner scan the final tank, etc


And how is that going to save money?
And what good will it do to use certified material when it keep getting rejected.  Anyways, the testing is done by the supplier before the material is delivered.
« Last Edit: 02/20/2016 01:46 PM by Jim »

Offline Jim

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Re: Atlas V and Centaur Q&A
« Reply #667 on: 02/20/2016 01:42 PM »
Given the high entry hurdles there is a small chance that new, more advanced companies enter the market.


Why would the new ones be anymore "advanced" than the existing one?

You have the wrong takeaway on the whole industry.

Offline Grandpa to Two

Re: Atlas V and Centaur Q&A
« Reply #668 on: 03/23/2016 12:35 AM »
Could someone explain what exactly is in the plastic/glass covered column on the left side of the booster? This is the first photo I've seen where I can see into it some. I figure it's electronics for motors and guidance am I correct? Is there more to it? Regards
"All truths are easy to understand once they are discovered; the point is to discover them" Galileo Galilei

Offline Jim

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Re: Atlas V and Centaur Q&A
« Reply #669 on: 03/23/2016 01:08 AM »
That is the booster avionics pod. It will be covered later in the flow

Offline Graham

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Re: Atlas V and Centaur Q&A
« Reply #670 on: 03/23/2016 02:23 AM »
During launches one of the common things I hear is "Body rates look good". Could someone explain what exactly that means?
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Offline Jim

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Re: Atlas V and Centaur Q&A
« Reply #671 on: 03/23/2016 02:27 AM »
During launches one of the common things I hear is "Body rates look good". Could someone explain what exactly that means?

The angular rates of the vehicle
« Last Edit: 03/23/2016 02:28 AM by Jim »

Offline shooter6947

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Re: Atlas V and Centaur Q&A
« Reply #672 on: 03/23/2016 03:24 AM »
Watching the feed tonight I finally got a sense for how underpowered the RL-10 is on the Centaur.  Acceleration was only around 6 m/s^2 and the lofted trajectory had it falling for most of its burn, with huge vector losses.  Hence the 2-RL-10 plan for Starliner launches, I presume.

Online Stan Black

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Re: Atlas V and Centaur Q&A
« Reply #673 on: 03/28/2017 11:03 AM »
So can someone help me understand this, please?

Quote
The outsized cargo payload to be transported by Volga-Dnepr from North Island NAS to Denver will consist of one LMSS Centaur III Launch Vehicle Upper Stage (AVC014)
http://www.airlineinfo.com/ostcarrier/volga2006.html

Is the AVC014 designator just a tail number, not the actual serial number?
And what were Centaur upper stages doing in North Island NAS?

Offline edkyle99

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Re: Atlas V and Centaur Q&A
« Reply #674 on: 03/28/2017 05:25 PM »
So can someone help me understand this, please?

Quote
The outsized cargo payload to be transported by Volga-Dnepr from North Island NAS to Denver will consist of one LMSS Centaur III Launch Vehicle Upper Stage (AVC014)
http://www.airlineinfo.com/ostcarrier/volga2006.html

Is the AVC014 designator just a tail number, not the actual serial number?
And what were Centaur upper stages doing in North Island NAS?
Very interesting.  They are discussing a move from San Diego to Denver during February 2006 to allow LMSS to meet a September 2006 shipment date to the Cape.  (Centaur structures were built in San Diego then.  I'm not sure if this is still true.)   The interesting thing is that AV-014 launched on April 14, 2008 with ICO G1 from the Cape.  I don't think the time-line for "AVC014" matches what I would expect for the AV-014 launch campaign.

Here's the launch history during 2006-2008.


01/19/06 Atlas 5-551  AV010 Pluto New Horizons    478  CC41                     HCO
04/20/06 Atlas 5-411  AV008 Astra 1KR            4332  CC41  6212x37786x23.97   GTO+
03/09/07 Atlas 5-401  AV013 STP-1 (OES+)         1400  CC41  560x560x35.4       LEO
06/15/07 Atlas 5-401  AV009 NROL-30R                   CC41 [842x1186x63.35]   [LEO](2)
10/11/07 Atlas 5-421  AV011 WGS-SV1              5770  CC41  477x66847x20.1     GTO+
12/10/07 Atlas 5-401  AV015 NROL-24 (SDS?)             CC41  261x16776x60       EEO/M
03/13/08 Atlas 5-411  AV006 NRO L-28                   VA3E  1200x39000x63      EEO/M
04/14/08 Atlas 5-421  AV014 ICO G1               6630  CC41  187x35925x22.7     GTO


I will offer up this speculation.  The document describes the stage to be a "Centaur III Launch Vehicle Upper Stage (AVC014)".  By the end of 2005 there had been four "Centaur III" flights on Atlas IIIB rockets and six on Atlas V rockets.  If we assume that "AVC014" refers to the 14th "Centaur III" stage*, and also assume that these stages flew sequentially (iffy), then the June 15, 2007 AV-009 launch of NROL-30R (the one that faltered short of its planned orbit**) seems a strong candidate for the stage being described in the Volga-Dnepr filing.  I suppose the AV-013 STP-1 launch is also a good candidate.

Upon further review of these transport filings, I see that AVB014 (Atlas) and AVC014 (Centaur) were flown from Denver to the Cape during early November, 2007.  This corresponds to the AV014 launch of ICO G1 on April 14, 2008.  The "September 2006" shipment deadline thus doesn't seem to have ended up applying to AVC014.  AVB013 and AVC013 were shipped to the Cape in August, 2006, just before that deadline, and I'll note that there was a gap in Atlas V shipments from February to August, 2006 for some reason.

 - Ed Kyle

* Notice that later filings discuss movement of the much larger "AVB008" stage, which must mean the Atlas   first stage.  Indeed, there are a whole slew of Atlas and Centaur stage movements described.
** Interesting coincidence?
« Last Edit: 03/28/2017 07:22 PM by edkyle99 »

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