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#120
by
bigdog
on 04 Mar, 2007 22:11
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edkyle99 - 4/3/2007 11:08 AM
Woulda, coulda, shoulda. It wasn't a DSP payload. The launch vehicle failed to meet the assigned objectives on this flight. There was a failure, a post-flight failure investigation, engineering changes to the vehicle design, etc.
- Ed Kyle
I won't continue the debate about Delta IV Heavy Demo but you make a point that I'd like to explore.
"failed to meet the assigned objectives"
Is it not the "assigned objective" of every launch to place the payload in a specific orbit (+ or - an allowable amount)? If so then how many flights of Delta, Atlas, Ariane etc. failed to reach the target orbit but were considered a "success" because the satellite was able to make up the shortfall?
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#121
by
Jim
on 04 Mar, 2007 22:22
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bigdog - 4/3/2007 6:11 PM
If so then how many flights of Delta, Atlas, Ariane etc. failed to reach the target orbit but were considered a "success" because the satellite was able to make up the shortfall?
They weren't called successes. The Delta II that carried a solid through the whole first stage flight was called a failure even though the spacecraft made it to orbit. Part of the success criteria is the spacecraft arriving on station with the projected lifetime fuel load.
so none for Delta and Atlas.
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#122
by
Jim
on 04 Mar, 2007 22:39
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D-IV was designed with propellant tanks sized too small. The Medium fails to meet the 10k kb to GTO requirement. So they had to save weight and therefore the CBC's were optimized for each configuration.
Atlas was overized to make sure it met requirements. They kept the CCB as generic as possible to save costs. The Heavy CCB would have kits to adapt it.
The SRM attach points extra weight is minor.
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#123
by
Jim
on 05 Mar, 2007 14:59
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bigdog - 4/3/2007 5:32 PM
Jim - 3/3/2007 6:38 PM
The Atlas V SRB cables are missions kits, which can be added and subtracted at will, therefore each CCB coming off the line can be used for any configuration.
You need to do the research and recheck the lack of your facts. I know they are different from experience
I will re-check my facts but it's not a lack of them. My facts came from people who actually work on the hardware and from experience. That info may be a bit dated so I'll double check but it would help me if you could explain how those parts of the CBC you speak of are not the same.
You say the tanks are different, how? Thinner/thicker, shorter/longer etc.?
If the 2 SRM CBC has mounts for 4 SRM's it would seem it only lacks the "mission kits" that Atlas does. How is it not the same?
Also how does the Atlas come off the line? No SRM Kits installed or the number planned for that mission?
I don't want to argue with you and did not intend to as you clearly know a lot about these vehicles. I look for your help to better undrstand your position. 
These are the numbers of different configurations of components of a D-IV CBC:
4 interstages
2 forward LO2 skirts
3 LO2 tanks
2 centerbodies
3 LH2 tanks
2 Aft LH2 skirts
6 Engine sections
The only two configurations that use the same CBC is the Med+ 5,2 and 5,4. The Med + 4,2 has a diffent engine section, not to mention the interstage
All three heavy CBC's are different.
Eliminate the heavy and there are still 3 different CBC's. The Medium shares nothing in common with the Med + 4,2
I will correct myself, Atlas has 2 CCB's types. One for the heavy and the one for all other configurations
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#124
by
kevin-rf
on 05 Mar, 2007 17:25
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Jim - 5/3/2007 9:59 AM
These are the numbers of different configurations of components of a D-IV CBC:
4 interstages
2 forward LO2 skirts
3 LO2 tanks
2 centerbodies
3 LH2 tanks
2 Aft LH2 skirts
6 Engine sections
The only two configurations that use the same CBC is the Med+ 5,2 and 5,4. The Med + 4,2 has a diffent engine section, not to mention the interstage
All three heavy CBC's are different.
Eliminate the heavy and there are still 3 different CBC's. The Medium shares nothing in common with the Med + 4,2
I will correct myself, Atlas has 2 CCB's types. One for the heavy and the one for all other configurations
So how does that work out?
Med +4,2
unique engine section
unique interstage
Same LOX,LH,tanks,skirts,center bodies with others
Med +5,2
unique engine section
unique interstage
Same LOX,LH,tanks,skirts,center bodies with others
Med +5,4
unique engine section
unique interstage
Same LOX,LH,tanks,skirts,center bodies with others
Heavy
three Different engine sections, one for each CBC
unique interstage
Three Different LOX,LH one for each CBC
how do the LOX,LH skirts and center bodies fit into this?
How do we mix and match all the parts?
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#125
by
Jim
on 05 Mar, 2007 17:50
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bigdog - 4/3/2007 5:32 PM
Jim - 3/3/2007 6:38 PM
The Atlas V SRB cables are missions kits, which can be added and subtracted at will, therefore each CCB coming off the line can be used for any configuration.
Also how does the Atlas come off the line? No SRM Kits installed or the number planned for that mission?
I don't want to argue with you and did not intend to as you clearly know a lot about these vehicles. I look for your help to better undrstand your position.
I was wrong. All the single core CCB's have all the SRB wiring installed. There is no mission mods needed to add or subtract an SRB. An Atlas can be changed between a 4XX and 5XX as late as when the CCB is stacked in the VIF. Centaurs can be swapped out later.
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#126
by
Jim
on 05 Mar, 2007 17:50
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kevin-rf - 5/3/2007 1:25 PM
How do we mix and match all the parts?
The rest is left up to the reader
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#127
by
edkyle99
on 05 Mar, 2007 18:04
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bigdog - 4/3/2007 5:11 PM
edkyle99 - 4/3/2007 11:08 AM
Woulda, coulda, shoulda. It wasn't a DSP payload. The launch vehicle failed to meet the assigned objectives on this flight. There was a failure, a post-flight failure investigation, engineering changes to the vehicle design, etc.
- Ed Kyle
I won't continue the debate about Delta IV Heavy Demo but you make a point that I'd like to explore.
"failed to meet the assigned objectives"
Is it not the "assigned objective" of every launch to place the payload in a specific orbit (+ or - an allowable amount)? If so then how many flights of Delta, Atlas, Ariane etc. failed to reach the target orbit but were considered a "success" because the satellite was able to make up the shortfall?
As Jim noted, no Delta 2 or Atlas failures in recent years have left a satellite able to achieve its orbit by itself. The most recent example worldwide of this type of failure was on June 29, 2004, when Zenit 3SL-20 suffered a Blok DMSL upper stage failure that left the Apstar 5 payload short of its planned transfer orbit. The upper stage shut down 54 seconds early due to an electrical system failure that caused the engine to burn fuel too fast.
The insertion orbit was 722 x 21618 km versus the planned 756 x 35929 km. Apstar 5 was subsequently able to propel itself to GEO, reportedly with a minimal lifetime impact. As a result, many reports call this launch a success even though it clearly was not a *launch vehicle* success. The launch vehicle suffered an actual hardware failure that caused it to substantially miss its mark. In my book, this one goes down as a launch vehicle failure despite the relatively happy ending for the customer.
- Ed Kyle
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#128
by
Analyst
on 06 Mar, 2007 07:36
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edkyle99 - 4/3/2007 7:08 PM
Although the Apollo 6 mission was able to achieve some of its objectives, AS-502 was a launch vehicle failure, plain and simple. The S-IVB stage failed to restart. The SLA suffered a structural failure. Etc.
With DSP it *would" have achived GEO.
Woulda, coulda, shoulda. It wasn't a DSP payload. The launch vehicle failed to meet the assigned objectives on this flight. There was a failure, a post-flight failure investigation, engineering changes to the vehicle design, etc.
- Ed Kyle
Come on Ed, the world is not only black and white, there are grays. I fully understand a customer or insurance company classifies a lower than planned orbit as a failure of the LV. And I fully understand you were in need of a clear definition of failure for the
purpose of your book. But a definition can't be right or wrong, only useful with regard to a purpose. If its purpose is to compare LV problems, you need more than success and failure. You need the grays. Again, I don't want to talk the maiden voyage of the Delta IVH better than it was, but if you compare it to Ariane V, it was way better. And the fact DSP would have reached GEO is an indication for this.
Would you classify AS-502 a failure if only the SLA problem (and not the multiple engine problems) occured? There was no complete structural failure of the SLA, if it has been, the CSM could not have reached orbit. The SLA served its purpose of structurally connecting SIVB and CSM.
Analyst
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#129
by
edkyle99
on 06 Mar, 2007 14:47
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Analyst - 6/3/2007 2:36 AM
Come on Ed, the world is not only black and white, there are grays. I fully understand a customer or insurance company classifies a lower than planned orbit as a failure of the LV. And I fully understand you were in need of a clear definition of failure for the purpose of your book. But a definition can't be right or wrong, only useful with regard to a purpose. If its purpose is to compare LV problems, you need more than success and failure. You need the grays. Again, I don't want to talk the maiden voyage of the Delta IVH better than it was, but if you compare it to Ariane V, it was way better. And the fact DSP would have reached GEO is an indication for this.
If you were shopping for a launch for your hundreds-of-millions-dollars satellite, or if you were insuring such a launch, you would not be interested in "gray areas". A so-called "partial success" could cost you everything.
These "gray areas" and "partial successes", etc. are unfortunately used by some to essentially misrepresent what really happened. In my mind, it is more accurate and truthful to "round down" than to "round up" when accumulating launch vehicle reliability data.
Would you classify AS-502 a failure if only the SLA problem (and not the multiple engine problems) occured? There was no complete structural failure of the SLA, if it has been, the CSM could not have reached orbit. The SLA served its purpose of structurally connecting SIVB and CSM.
Analyst
If the SA-502 third stage had restarted and propelled the Apollo spacecraft to its planned injection orbit, and if no damage had occurred to the "payload", then I would have classified SA-502 as a launch vehicle success despite the SLA problem. A launch vehicle success is only registered when the launch vehicle injects its payload, undamaged, into or very nearly into the planned orbit.
Now the "AS-502" (Apollo 6 spacecraft/mission) question is not the same as the "SA-502" (launch vehicle) question. The Apollo 6 mission was able to achieve some, but not all, objectives, despite the failure of the launch vehicle.
- Ed Kyle
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#130
by
bigdog
on 08 Mar, 2007 23:56
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Jim - 5/3/2007 8:59 AM
These are the numbers of different configurations of components of a D-IV CBC:
4 interstages
2 forward LO2 skirts
3 LO2 tanks
2 centerbodies
3 LH2 tanks
2 Aft LH2 skirts
6 Engine sections
The only two configurations that use the same CBC is the Med+ 5,2 and 5,4. The Med + 4,2 has a diffent engine section, not to mention the interstage
All three heavy CBC's are different.
Eliminate the heavy and there are still 3 different CBC's. The Medium shares nothing in common with the Med + 4,2
Okay I will say that I was incorrect in saying the CBC's are the "same". They are different but not to the extent that I I felt they are not common.
For example:
Centerbodys for the strap-on boosters have less avionics. Other than that I can't find anything else.
Engine sections for strap-ons have unique attachments for connecting to the core and they are left vs. right. The 4,2 has an aeroskirt and different thermal shield and the strap-on shields contain the separation motors.
My take is the differences are piece parts required or not because of the ultimate vehicle configuration which drive different configuration part numbers at the final assembly level. Can you please be more specific about what's different in your list above? I'm just not sure the differences are a big deal in the big picture or that they make it less common.
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#131
by
Jim
on 09 Mar, 2007 01:48
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bigdog - 8/3/2007 7:56 PM
Centerbodys for the strap-on boosters have less avionics. Other than that I can't find anything else.
Engine sections for strap-ons have unique attachments for connecting to the core and they are left vs. right. The 4,2 has an aeroskirt and different thermal shield and the strap-on shields contain the separation motors.
My take is the differences are piece parts required or not because of the ultimate vehicle configuration which drive different configuration part numbers at the final assembly level. Can you please be more specific about what's different in your list above? I'm just not sure the differences are a big deal in the big picture or that they make it less common.
The centerbody differences are structural and have nothing to do with avionics.
Aeroskirts were not included.
The tanks and tank skirts (skin thicknesses, gage thicknesses) are different and can't be changed from one type to another just by the addition or subtraction of parts. The basic construction is different from day one of production. Can't swap components.
Let's eliminate the Heavy parts and see what is left.
3 interstages
2 forward LO2 skirts
2 LO2 tanks
2 centerbodies
2 LH2 tanks
2 Aft LH2 skirts
3 Engine sections
Per my other post, let's eliminate the medium parts
2 interstages
1 forward LO2 skirts
1 LO2 tanks
1 centerbodies
1 LH2 tanks
1 Aft LH2 skirts
2 Engine sections
Aside from the heavy CBC's, there are big differences in the the Mediums.
Atlas chose to make the interstage a field installation to allow the 5XX and 4XX CCB's to be the same. If Delta did this, there still is a difference in the Med + CBC's due to the engine section.
Going back to the Med, it was so underperforming that a light version of all the components was needed and it still doesn't meet the EELV specs.
P.S.
WRT Heavy strapon, Atlas V would have one version that can be used in any position
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#132
by
Nick L.
on 09 Mar, 2007 03:37
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So let me see if I've got this straight.
Interstages
Medium+(4,2) 4-meter
Medium 4-meter lightweight
Medium+(5,X) 5-meter
Heavy 5-meter with strap-on CBC attach points
Fwd LOX skirts:
Standard for all variants except Med.
Medium lightweight
LOX tanks
Medium+ standard
Heavy standard
Medium lightweight
Why are the Heavy LOX tanks different from the ones used on the M+ versions?
Centerbodies
Standard for all variants except Med.
Medium lightweight
LH2 tanks
Heavy standard gauge, no mount points
Medium+ standard gauge, mount points
Medium lightweight
Aft LH2 skirts? Where is this part on the vehicle?
Engine sections:
Heavy port, center, and starboard with respective mount points
Medium+ with 2 solids
Medium+ with 4 solids (I thought that this and the above were the same, the M+ with 2 solids seems to have the other two mount points)
Medium lightweight
Have I got all of this correct? I guess you learn something new everyday!
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#133
by
Jim
on 09 Mar, 2007 07:05
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the engine section for the Med + 4,2 is different than the Med + 5,X.
Remember the Med + 5,2 and Med + 5,4 are the only configurations that use the same CBC
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#134
by
publiusr
on 30 Mar, 2007 19:24
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Jim - 4/3/2007 5:39 PM
D-IV was designed with propellant tanks sized too small.
That's why some folks wanted Magnum/CaLV,ALS/NLS etc. Keep all your low-density, high volume LH2 in one very large tank with multiple engines burning off that.
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#135
by
Jim
on 31 Mar, 2007 00:32
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publiusr - 30/3/2007 3:24 PM
Jim - 4/3/2007 5:39 PM
D-IV was designed with propellant tanks sized too small.
That's why some folks wanted Magnum/CaLV,ALS/NLS etc. Keep all your low-density, high volume LH2 in one very large tank with multiple engines burning off that.
Undersized tanks.
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#136
by
fatjohn1408
on 07 Jul, 2013 19:26
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The answer just boils down to the following:
The European institutional market is a) not obliged to use the Ariane V and b) not big enough to keep its launch frequency at an acceptible pace.
The US institutional market is big enough and needs to launch domestically.
Therefore ULA does not need to hunt on the commercial market for unprofitable payloads and customers. Arianespace does need to do this and they can because Europe (ESA and CNES i think) have as a mission to provide access to space for Europe. That is the reason Europe has an accompaniment programme for Arianespace.
But at the moment Arianespace is quite close to break even on their commercial launches (read close to being profitable), while ULA is still not competing for the market (read: cannot be profitable on the market and thus choose to remain active only on the profitable institutional market, a choice Arianespace does not have.)
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#137
by
John-H
on 07 Jul, 2013 21:34
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If ULA charged government prices on the commercial market, would anyone buy?
If they charged commercial prices to the government, they would go broke.
If they charged two different prices for the same launch service, wouldn't they have severe problems with the government accounting office?
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#138
by
spectre9
on 08 Jul, 2013 01:55
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Nobody has asked ULA for a large enough bulk buy to get a discount.
At least there's no public knowledge of such an offer.
Inmarsat has used the Atlas V when they really needed to capture the market. They're my favourite satellite provider. They get things done.
