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#300
by
yinzer
on 08 Nov, 2006 01:31
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bombay - 7/11/2006 5:16 PM
Well, I guess I had that coming! My apologies to all!
Admittedly, I'm weak in the Keplerian elements, but here goes for argument sake using the AV-001 launch listed above in the discussion.
The SV was 3905 kg and was placed in the transfer orbit mentioned on Atlas V. You claim that The Atlas III would not be able to place the 3905 kg SV in the same orbit. Here's my spin on things:
Lets assume the booster could only travel at max speed of 5300 mph as maximum dynamic pressure on the SV is achieved. After about T+4.5 minutes into flight, booster separation occurs and the Centaur then takes over for the duration of the T+30-35 minute flight.
Now, given that the Atlas III could handle a SV mass of 3905 kg and can travel at 5300 mph at Max-Q, upon separation at T+4.5, the Centaur and payload would be in the same relative location in space as with the Atlas V.
So the Centaur, not the Atlas, is the x-factor in achieving the perigee, apogee, and inclination that you listed.
You have no idea what the hell you are talking about. I mean this not as an insult, just as a statement of fact. The Centaur on the Atlas V is the same as the Centaur on the Atlas IIIB. Even the most basic internet searching and reading about the evolution of the Atlas will tell you this. I can't tell if you have no desire to learn, or have just very effectively internalized the advice that the best way to get information on the internet is not to ask questions but to make incorrect assertions.
Regardless, this is losing its entertainment value.
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#301
by
Nick L.
on 08 Nov, 2006 02:03
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bombay - 7/11/2006 7:16 PM
yinzer - 7/11/2006 1:13 AM
bombay - 6/11/2006 9:35 PM
I need some clarification here. To my understanding a supersynchronous orbit is achieved when the satellite becomes nonoperational. In other words, supersynchronous amounts to a junkyard for space debris that's out of the way of things to avoid collisions and such. The satellite isn't initially placed there, it manuevers itself there at the end of its useful life.
Maybe there's some logical reason behind placing $700 million satellites into the boneyard before serving their useful purpose in GTO, but I can't think of any.
For all of Jim's curtness, at least he doesn't pull the "I don't understand the field, but I'll claim that the people doing it are stupid anyway" move, as you are doing here.
You can actually "I'm Feeling Lucky" "supersynchronous transfer orbit" on Google and get something that explains what Jim is talking about. Or, you can think about how you might get more out of a launch vehicle when you are trying to get your satellite into geostationary orbit, and you don't want to have to restart the launch vehicle upper stage after a 7-hour coast.
Or, you could say "supersynchronous orbit? what's that?" without the hostility, in which case someone would say "ah, well, if you want to get more performance out of your LV without making your satellite bigger, you can have the LV put you into a transfer orbit with a higher apogee, which reduces the delta-V from the transfer orbit to GTO and saves satellite propellant, so you can either carry more payload or use your propellant for station-keeping rather than gross orbital maneuvering."
Also, since it's possible that some might not be convinced that Jim is right, let's look at the previously mentioned Atlas V missions. Initial transfer orbit data is available from Jonathan's Space Report here, and I have a copy of the old Atlas Mission Planner's Guide. We can't find the exact orbits, but once you get into serious inclination reductions the payload-vs-inclination curve straightens out, so it's easy to approximate.
AV-001: 3905 kg to 304km x 45349km x 17.5 deg - Atlas IIIB can do 3730 kg to 166km x 35786km x 18.0 deg
AV-002: 3250 kg to 403km x 84651km x 17.0 deg - Atlas IIIB can probably do 3167 kg to 166km x 85000km x 17.0 deg
AV-003: 4328 kg to 3815km x 35761km x 17.5 deg - Atlas IIIB can do 3730 kg to 166km x 35786km x 18.0 deg
AV-005: 4065 kg to 4820km x 35717km x 18.0 deg - Atlas IIIB can do 3730 kg to 166km x 35786km x 18.0 deg
So, indeed, none of the first five Atlas missions could have flown on an Atlas III.
Well, I guess I had that coming! My apologies to all!
Admittedly, I'm weak in the Keplerian elements, but here goes for argument sake using the AV-001 launch listed above in the discussion.
The SV was 3905 kg and was placed in the transfer orbit mentioned on Atlas V. You claim that The Atlas III would not be able to place the 3905 kg SV in the same orbit. Here's my spin on things:
Lets assume the booster could only travel at max speed of 5300 mph as maximum dynamic pressure on the SV is achieved. After about T+4.5 minutes into flight, booster separation occurs and the Centaur then takes over for the duration of the T+30-35 minute flight.
Now, given that the Atlas III could handle a SV mass of 3905 kg and can travel at 5300 mph at Max-Q, upon separation at T+4.5, the Centaur and payload would be in the same relative location in space as with the Atlas V.
So the Centaur, not the Atlas, is the x-factor in achieving the perigee, apogee, and inclination that you listed.
No, as Jim said it's the Atlas doing the work. You can see here:
http://spaceflightnow.com/atlas/av001/status.htmlthe Atlas V MECO (BECO, whatever floats your boat
) occurs at T+4:10.
Now compare to here:
http://www.spaceflightnow.com/atlas/ac206/status.htmlAtlas III's MECO occurs at T+3:09.
One minute makes a big difference to the energy being inputted into the Centaur, and therefore the payload capacity. This is where most of the payload gain of Atlas V vs. Atlas III comes from.
Remember only 17 seconds stood between the Delta IV Heavy and a fully successful mission.
Nick
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#302
by
bombay
on 08 Nov, 2006 03:18
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yinzer - 7/11/2006 8:14 PM
bombay - 7/11/2006 5:16 PM
Well, I guess I had that coming! My apologies to all!
Admittedly, I'm weak in the Keplerian elements, but here goes for argument sake using the AV-001 launch listed above in the discussion.
The SV was 3905 kg and was placed in the transfer orbit mentioned on Atlas V. You claim that The Atlas III would not be able to place the 3905 kg SV in the same orbit. Here's my spin on things:
Lets assume the booster could only travel at max speed of 5300 mph as maximum dynamic pressure on the SV is achieved. After about T+4.5 minutes into flight, booster separation occurs and the Centaur then takes over for the duration of the T+30-35 minute flight.
Now, given that the Atlas III could handle a SV mass of 3905 kg and can travel at 5300 mph at Max-Q, upon separation at T+4.5, the Centaur and payload would be in the same relative location in space as with the Atlas V.
So the Centaur, not the Atlas, is the x-factor in achieving the perigee, apogee, and inclination that you listed.
You have no idea what the hell you are talking about. I mean this not as an insult, just as a statement of fact. The Centaur on the Atlas V is the same as the Centaur on the Atlas IIIB. Even the most basic internet searching and reading about the evolution of the Atlas will tell you this. I can't tell if you have no desire to learn, or have just very effectively internalized the advice that the best way to get information on the internet is not to ask questions but to make incorrect assertions.
Regardless, this is losing its entertainment value.
As I stated, the scenario was for argument sake, not as a statement of fact. If you read the post, you would see that I said, "here's my spin on things". This should have been a clue that I wasn't stating fact. Both Jim and Nick L. recognized this and responded with some facts that told me my scenario held no water.
You might have also concluded that I am trying to learn something by creating a scenario based on intuition that I would expect others in the know to pick apart, which they did.
The scenario had nothing to do with a different Centaur, I don't know where you came up with that.
Your personal attacks on me are out of line. I may have a different point of view on things and will volley back and forth, but I don't blatantly attack anyones intelligence in a condescending manner. Consider following your own advise by not acting so hostile! I'm out.
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#303
by
Dexter
on 08 Nov, 2006 03:46
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yinzer - 7/11/2006 1:13 AM
For all of Jim's curtness, at least he doesn't pull the "I don't understand the field, but I'll claim that the people doing it are stupid anyway" move, as you are doing here.
You can actually "I'm Feeling Lucky" "supersynchronous transfer orbit" on Google and get something that explains what Jim is talking about. Or, you can think about how you might get more out of a launch vehicle when you are trying to get your satellite into geostationary orbit, and you don't want to have to restart the launch vehicle upper stage after a 7-hour coast.
Or, you could say "supersynchronous orbit? what's that?" without the hostility, in which case someone would say "ah, well, if you want to get more performance out of your LV without making your satellite bigger, you can have the LV put you into a transfer orbit with a higher apogee, which reduces the delta-V from the transfer orbit to GTO and saves satellite propellant, so you can either carry more payload or use your propellant for station-keeping rather than gross orbital maneuvering."
Also, since it's possible that some might not be convinced that Jim is right, let's look at the previously mentioned Atlas V missions. Initial transfer orbit data is available from Jonathan's Space Report here, and I have a copy of the old Atlas Mission Planner's Guide. We can't find the exact orbits, but once you get into serious inclination reductions the payload-vs-inclination curve straightens out, so it's easy to approximate.
AV-001: 3905 kg to 304km x 45349km x 17.5 deg - Atlas IIIB can do 3730 kg to 166km x 35786km x 18.0 deg
AV-002: 3250 kg to 403km x 84651km x 17.0 deg - Atlas IIIB can probably do 3167 kg to 166km x 85000km x 17.0 deg
AV-003: 4328 kg to 3815km x 35761km x 17.5 deg - Atlas IIIB can do 3730 kg to 166km x 35786km x 18.0 deg
AV-005: 4065 kg to 4820km x 35717km x 18.0 deg - Atlas IIIB can do 3730 kg to 166km x 35786km x 18.0 deg
So, indeed, none of the first five Atlas missions could have flown on an Atlas III.
Yinzer
Thanks for taking the time to offer a decent explanation. I sincerly appreciate it.
What you are telling me is that the advertised GTO mission and its capability as advertised in the Mission Planner's Guides is for a basic orbit with a high apogee and low perigee and that the excess performance in the rocket can be used to reduce the amount of energy required for the apogee burn. So this then becomes a trade similar to the discussion on GTO vs. GSO.
What I take exception to is the statement Jim made and I quote,
"A-III could not have done any of the missions that A-V flown."
It seems to me that any satellite weighing lesss than 9920 lbs can reach a GTO orbit on an Atlas 3 but will require more propellant on the apogee burn. So in my mind, the statement is incorrect.
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#304
by
yinzer
on 08 Nov, 2006 04:03
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Dexter - 7/11/2006 8:29 PM
Yinzer
Thanks for taking the time to offer a decent explanation. I sincerly appreciate it.
What you are telling me is that the advertised GTO mission and its capability as advertised in the Mission Planner's Guides is for a basic orbit with a high apogee and low perigee and that the excess performance in the rocket can be used to reduce the amount of energy required for the apogee burn. So this then becomes a trade similar to the discussion on GTO vs. GSO.
Exactly - "GTO" is an imprecisely defined term. And I am glad that I can help.
What I take exception to is the statement Jim made and I quote,
"A-III could not have done any of the missions that A-V flown."
It seems to me that any satellite weighing lesss than 9920 lbs can reach a GTO orbit on an Atlas 3 but will require more propellant on the apogee burn. So in my mind, the statement is incorrect.
Well... I think Jim is right. The initial Delta IV Heavy mission put its payload into a noticeably lower orbit than the customer wanted, and while an actual satellite might have been able to maneuver into the final orbit at the cost of a large reduction in on-orbit lifetime, the flight should still be considered a failure. Similarly, if Echostar wants their satellite put into a supersynchronous transfer orbit at 18 degrees inclination, and the Atlas III can only put it into a standard GTO at 27 degrees, Echostar will consider it a failure.
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#305
by
Dexter
on 08 Nov, 2006 04:16
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Jim - 7/11/2006 6:36 AM
Dexter and Bombay
obviously, you both aren't in the industry or you wouldn't be having such a hard time understanding rocket science. Know something about a subject before posting again.
"Why would Lockhed build a standardized satellite and then have it not fit into a 4 meter fairing when a lot of the other ones appear to fit 4m fairings including Echostar 7"
The bus is not the only thing flying, there is a payload section (the part the customer really wants in space). The payload section is sometimes larger than the bus. There was a reason for the use of the 5m fairing, otherwise it could have flown on a 421 or 411. Either way, they still couldn't have flown on a A-III
Who made you king???
All the A2100AX satellites have flown on Proton, Atlas, Zenit, or Arianne (44L-H10-3)
The outside diameter of the Proton fairing is a little over 4m per
www.ilslaunch.comThe fairinings offered by Arianne on the 44L-H10-3 supplied by either Contraves or Long Spelda are 4meter fairings per Gunter's space page. The Zenit used by Sea Launch uses a 4 meter fairing
http://www.boeing.com/special/sea-launch/sllaunch_vehicle.htm#2Proton, Zenit(Sea Launch) and Arianne all launched A2100AX satellites with higher mass than Rainbow 1.
Astra 1kr was launched on an Atlas V 411 which was a heavier spacecraft mass than Rainbow 1 (Atlas V 521).
So I can draw several conclusion (they will probably be wrong of course
)
1) Rainbow 1 did not need the 5 meter fairing but Atlas chose to fly it to demonstrate capability.
2) Lockheed decided to build one satellite out of class from the rest of A2100AX family that was more volumous in spite not being the heaviest in the family (See Gunter's Space Page -
http://www.skyrocket.de/space/ )
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#306
by
Dexter
on 08 Nov, 2006 04:21
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How did we get way off topic?
30 days have passed since FTC decided to intervene and hold for public comment.
Nothing new on the FTC web site.
Maybe that Yahoo message board wasn't that far off the mark.
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#307
by
Dexter
on 08 Nov, 2006 04:31
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yinzer - 7/11/2006 10:46 PM
.... Similarly, if Echostar wants their satellite put into a supersynchronous transfer orbit at 18 degrees inclination, and the Atlas III can only put it into a standard GTO at 27 degrees, Echostar will consider it a failure.
I understand and agree with that. This is where the trade comes in on the cost of that performance versus on orbit life. Please note that the missions I cited were in fact lower in spacecraft mass than the advertised max for a 3B.
It would be intersting to know how much additional fuel is required for the apogee burn(s) and how much degradation would occur to on-orbit life as a result.
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#308
by
yinzer
on 08 Nov, 2006 06:01
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Dexter /11/2006 9:14 PM
I understand and agree with that. This is where the trade comes in on the cost of that performance versus on orbit life. Please note that the missions I cited were in fact lower in spacecraft mass than the advertised max for a 3B.
But it's the customer who makes that call. Or rather, if the customer wants 1000 kg of payload bolted to the bus and 15 years of on-orbit lifetime, the launch provider can go back and forth with the customer on how much of that should come from the launch vehicle and how much should come from the satellite. But with the Atlas IIIB, the LV provider would be saying "Well, we can give you 1000 kg of payload and 10 years of on-orbit lifetime, but it'll be cheaper. Maybe." It's different.
As for the additional fuel, the Atlas Mission Planners Guide has charts of payload vs. delta-V to GTO, and if you assume the specific impulse of the apogee boost motor is 320 seconds, you'll come close. DeltaV = ln(wet mass / dry mass) * specific impulse * 9.8 m/s^2.
Americanized RD-180, no one cares enough about it to pay for the work. The USAF and NRO claim to care, but by their failure to get Lockheed to take concrete action, I suspect that they are pretending to care to keep Congress of their back. I also suspect that NASA only claimed to care as a way to justify the Stick.
As for Rainbow 1, according to ILS, "The larger fairing was chosen to accommodate the satellite's sophisticated antenna array," just like Jim said.
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#309
by
Dexter
on 08 Nov, 2006 06:15
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Yinzer,
Once again, good post and thanks for the info.
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#310
by
Jim
on 08 Nov, 2006 11:38
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Dexter - 8/11/2006 12:14 AM
yinzer - 7/11/2006 10:46 PM
.... Similarly, if Echostar wants their satellite put into a supersynchronous transfer orbit at 18 degrees inclination, and the Atlas III can only put it into a standard GTO at 27 degrees, Echostar will consider it a failure.
I understand and agree with that. This is where the trade comes in on the cost of that performance versus on orbit life. Please note that the missions I cited were in fact lower in spacecraft mass than the advertised max for a 3B.
It would be intersting to know how much additional fuel is required for the apogee burn(s) and how much degradation would occur to on-orbit life as a result.
The mass AND orbit are what determine the LV capability. The end state of the LV mission varies. GTO and GSO are not the only ones. Some spacecraft ask for subsynchronous transfer orbits also. Or even 3 burn missions, like GOES-N, where the Delta -IV use excess performance for the 2nd stage to perform a 3rd burn at GEO altitude to remove inclination and raise perigee.
This is an extreme example, stating those missions could be flown by A-III is like saying Delta II could carry MRO because it can lift 5k lb to LEO
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#311
by
Jim
on 08 Nov, 2006 11:49
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Now after all that. A-III wasn't discontinued to eliminated "internal" competition. Customers were outgrowing (weight and size) it. And also even if there is no satellite weight growth, longer onorbit life wins trades with increased launch costs (i.e X more months onorbit is worth Y more in launch costs)
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#312
by
skywalker
on 09 Nov, 2006 03:51
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Wow a guy goes away for a couple of weeks and this forum goes ballistic, pun intended!
The Atlas V is really a Titan V, the Atlas program has been Martinized!
ULA is being formed because Lockheed and Boeing want out of the rocket business, the Air Force does not want to down select to either company - one with an under performing Delta IV or the other with a Russian engine & balloon upper stage Titan V, ULA is one company and thus the Air Force has down selected to one company.
ULA delays
Boeing Buy 3 still not resolved - Boeing still wants the government to pay a gazillion dollars for there mistakes
Boeing and Lockheed can not agree on what is 50-50, who brings what to the table.
Government knows
ULA will not save a dime and will be less reliable. National Security, well they are willing to accept that risk because the other option is no ULA and only one LV possibly none, at least one company will no longer put money into their program and possibly both will end it so what is the government to do, use Space X?
The reliability factor will be due to, Consolidation, the fact that key Boeing People will not move to Denver and key Lockheed people will not move to Decatur, so why consolidate? Well simple companies go into business to make money and ULA is no different. Quality of product and reliability do not really matter only profit once the contracts are set so is ULA. Upper management does not really care about anything except getting ULA started because of the MICP (Management Incentive Compensation Plan). They are actually hoping very few transfer to keep the payroll down (I know this is a small portion of the total cost) but less people improve share holder value.
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#313
by
Gus
on 09 Nov, 2006 03:54
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This has been quite an entertaining thread.
Keep in mind that IIAR was supposed to be scarred for solids as a IIARS for article three and on prior to redesignating it as the Atlas III. The edict to delete solids was shall we say not done in the typical manner that most engineering changes are done. Lots of analysis work went down the toilet. With Titan IV phasing out, there was a need to keep those folks busy. All of this, however, is water under the bridge.
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#314
by
Dexter
on 09 Nov, 2006 05:37
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Now that is interesting.
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#315
by
Dexter
on 09 Nov, 2006 05:43
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Getting this thread back on topic:
2 companies protest ULA; FTC decision expected soon on satellite rocket venture
http://www.decaturdaily.com/decaturdaily/news/061103/rocket.shtmlDown at the bottom there is this little gem,
"Lockheed has said the merger would add hundreds of workers here, although a recent article in the Denver Post quoted a Lockheed official as saying "only a couple of dozen" Lockheed workers would move to Decatur."
Couple of dozen would be 12 x 2 = 24. That doesn't seem like a lot of people needed to build one of these things.
Why do they cost so much?
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#316
by
Propforce
on 09 Nov, 2006 05:46
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skywalker - 8/11/2006 8:34 PM
Wow a guy goes away for a couple of weeks and this forum goes ballistic, pun intended!
The Atlas V is really a Titan V, the Atlas program has been Martinized!
ULA is being formed because Lockheed and Boeing want out of the rocket business, the Air Force does not want to down select to either company - one with an under performing Delta IV or the other with a Russian engine & balloon upper stage Titan V, ULA is one company and thus the Air Force has down selected to one company.
ULA delays
Boeing Buy 3 still not resolved - Boeing still wants the government to pay a gazillion dollars for there mistakes
Boeing and Lockheed can not agree on what is 50-50, who brings what to the table.
Government knows
ULA will not save a dime and will be less reliable. National Security, well they are willing to accept that risk because the other option is no ULA and only one LV possibly none, at least one company will no longer put money into their program and possibly both will end it so what is the government to do, use Space X?
The reliability factor will be due to, Consolidation, the fact that key Boeing People will not move to Denver and key Lockheed people will not move to Decatur, so why consolidate? Well simple companies go into business to make money and ULA is no different. Quality of product and reliability do not really matter only profit once the contracts are set so is ULA. Upper management does not really care about anything except getting ULA started because of the MICP (Management Incentive Compensation Plan). They are actually hoping very few transfer to keep the payroll down (I know this is a small portion of the total cost) but less people improve share holder value.
Finally, a straight shooter around here and not a mouth piece for the customer.
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#317
by
R&R
on 10 Nov, 2006 01:33
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Dexter - 9/11/2006 11:26 PM
Getting this thread back on topic:
2 companies protest ULA; FTC decision expected soon on satellite rocket venture
http://www.decaturdaily.com/decaturdaily/news/061103/rocket.shtml
Down at the bottom there is this little gem,
"Lockheed has said the merger would add hundreds of workers here, although a recent article in the Denver Post quoted a Lockheed official as saying "only a couple of dozen" Lockheed workers would move to Decatur."
Couple of dozen would be 12 x 2 = 24. That doesn't seem like a lot of people needed to build one of these things.
Why do they cost so much?
They are making more of the Lokheed statement than what it really is. Maybe only a couple dozen people will move to Decatur, can you blame the rest? But the number of people does not mean the number of Jobs. I don't know how many they have in Denver now but I'd guess 200 or more jobs will go to Decatur. Less the couple dozen that means a lot of jobs to fill. Unfortunately those that fill them probably won't have a tenth of the experience base.
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#318
by
R&R
on 10 Nov, 2006 01:40
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Speaking of the Decatur Daily article...
SpaceX is complaining because they want to play ball but don't have a bat so like all their other attempts to stop ULA it won't go anywhere.
NG I don't understand. They are worried about ULA/Boeing/LM stealing Satelite data but that didn't seem to be a concern with Boeing and LM all by themselves? I think the requirements by the FTC will put this one to bed also.
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#319
by
Propforce
on 10 Nov, 2006 02:49
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R&R - 9/11/2006 6:23 PM
NG I don't understand. They are worried about ULA/Boeing/LM stealing Satelite data but that didn't seem to be a concern with Boeing and LM all by themselves? I think the requirements by the FTC will put this one to bed also.
I don't understand NG's complaint neither. Essentially NG (TRW) satellites are being launched by either LM or Boeing now, so how would the formation of ULA be any different. It would actually be safer as ULA is a separate company from LM or Boeing (Bo-Mart?).
In addition, existing fire-wall is already in place now between the launch side and the satellite mfg side at Boeing. I am sure it's that way also with LM.
As far as adding workers in Decatur, I don't see existing workers that busy. I can see "cross-training" so they can assemble the Atlas V vehicles as well.
) occurs at T+4:10.