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#20 by Jim on 18 Jul, 2014 13:04
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Another question, would the cost of storing those satellites on the ground be higher than launching them: Perhaps
Not perhaps, but it is.
I think clearly the cost of X years of storage plus a launch in year X+1 is higher than a launch in year 1, unless the cost of launch in year X+1 is enough lower than the cost in year 1 that it covers the storage cost. So Jim is likely right, because launch costs are not likely to come down. Ever. No matter what happens.
But I don't think that's the right question. The right question is to ask what is the total cost of ownership of the entire GPS constellation (as birds die and get replaced) over the next N (where N is some large number, say 50) years. And I think there the argument can be made that IF you have sufficient on orbit spares already, why launch another spare now? Assuming the on orbit life is not diminished by storage, launching way more birds now than you need means you need replacement birds sooner and your TCO goes up.
It costs more because all the IIF spacecraft are built but the design and build team has to be maintained until the last of the series is on orbit. The USAF operates the spacecraft on orbit and so the required support from Boeing is much less.
Right now, the USAF is paying for two separate design and build teams; IIF (Boeing) & III (LM) -
#21 by macpacheco on 18 Jul, 2014 13:30
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Macpacheco, weren't you the one saying that they were not replenishing fast enough and should increase the rate?
Its true that a faster launch pace will speed up making L2C / M-Code signal operational.
But the really critical signal, L5 (essential for a complete migration from ground based navigation to satellite based navigation, specially retirement of billions USD worth of aging+obsolete ground equipment), is still 18 launches away from being operational, requiring all ordered GPS IIIA satellites plus a bunch of not even ordered ones.
I was consistently whining back when not even one launch / year was being executed, but on the other hand 3 or more launches per year is a waste of money, unless the plan is to launch a few more and stop for a few years.
Launching new GPS satellites too fast equals wasting perfectly good IIR GPS satellites. Lets get rid of the IIAs, those are really old and are performing much worse than the rest of the constellation.
But after launching IIF-7 + IIF-8 the constellation should have 27 healthy birds even with all IIA birds retired. Performance spec is for 27 birds.
The sweet spot is two launches per year.
It's a juggling act (conflicting priorities) between sustaining the constellation and preparing for M-Code/L2C FOC (and future L5 FOC).
The main GPS challenge right now is getting OCX fully operational and the first IIIA launched. Both projects are facing delays and (F35 like) SNAFUs. -
#22 by grythumn on 18 Jul, 2014 15:04
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Launching new GPS satellites too fast equals wasting perfectly good IIR GPS satellites. Lets get rid of the IIAs, those are really old and are performing much worse than the rest of the constellation.
But after launching IIF-7 + IIF-8 the constellation should have 27 healthy birds even with all IIA birds retired. Performance spec is for 27 birds.
The sweet spot is two launches per year.
It's a juggling act (conflicting priorities) between sustaining the constellation and preparing for M-Code/L2C FOC (and future L5 FOC).
The main GPS challenge right now is getting OCX fully operational and the first IIIA launched. Both projects are facing delays and (F35 like) SNAFUs.
They could also be planning on using the upper PRNs if needed for the GPS IIIA birds, and both exceeding the performance specs and giving themselves more on-orbit redundancy (I imagine they weren't happy with that GAO report from a while back).
But this has drifted to general GPS policy instead of mission specific (I don't think there IS an active general GPS thread...).
-Bob -
#23 by macpacheco on 18 Jul, 2014 16:40
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There are two bottlenecks to use the upper PRNs:Launching new GPS satellites too fast equals wasting perfectly good IIR GPS satellites. Lets get rid of the IIAs, those are really old and are performing much worse than the rest of the constellation.
But after launching IIF-7 + IIF-8 the constellation should have 27 healthy birds even with all IIA birds retired. Performance spec is for 27 birds.
The sweet spot is two launches per year.
It's a juggling act (conflicting priorities) between sustaining the constellation and preparing for M-Code/L2C FOC (and future L5 FOC).
The main GPS challenge right now is getting OCX fully operational and the first IIIA launched. Both projects are facing delays and (F35 like) SNAFUs.
They could also be planning on using the upper PRNs if needed for the GPS IIIA birds, and both exceeding the performance specs and giving themselves more on-orbit redundancy (I imagine they weren't happy with that GAO report from a while back).
But this has drifted to general GPS policy instead of mission specific (I don't think there IS an active general GPS thread...).
-Bob
1 - AEP have a 31 PRN almanac limit
2 - AEP can't assign PRN33-PRN36
OCX block I remove both limitations.
But OCX can't manage IIA GPS birds, one of the reasons another 2 launches are very important (pave the way to have all remaining IIA GPS decommissioned for OCX block I activation)
With IIF-1 ... IIF-8 healthy, there will be 28 IIR+IIRM+IIF birds in orbit, minus SVN49 that has that L5 test payload problem, leaves 27 healthy birds, just enough to produce a 24+3 compliant constellation layout even with all GPS IIA retired (enabling OCX activation)
Plus without OCX block I online, IIIA GPS can't be fully managed (can't be added to the almanac nor can be set healthy) -
#24 by vapour_nudge on 20 Jul, 2014 05:09
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Does anyone know the Atlas/Centaur tail number for this launch? AV-0xx ?
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#25 by Lar on 20 Jul, 2014 06:15
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I think clearly the cost of X years of storage plus a launch in year X+1 is higher than a launch in year 1, unless the cost of launch in year X+1 is enough lower than the cost in year 1 that it covers the storage cost. So Jim is likely right, because launch costs are not likely to come down. Ever. No matter what happens.
But I don't think that's the right question. The right question is to ask what is the total cost of ownership of the entire GPS constellation (as birds die and get replaced) over the next N (where N is some large number, say 50) years. And I think there the argument can be made that IF you have sufficient on orbit spares already, why launch another spare now? Assuming the on orbit life is not diminished by storage, launching way more birds now than you need means you need replacement birds sooner and your TCO goes up.
It costs more because all the IIF spacecraft are built but the design and build team has to be maintained until the last of the series is on orbit. The USAF operates the spacecraft on orbit and so the required support from Boeing is much less.
Right now, the USAF is paying for two separate design and build teams; IIF (Boeing) & III (LM)
Thanks for clarifying that, I hadn't thought about the support team aspect and reducing dups... What is the burn rate (yearly cost) on (each of) the teams, do we know off hand or is that proprietary? -
#26 by Galactic Penguin SST on 20 Jul, 2014 06:31
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Does anyone know the Atlas/Centaur tail number for this launch? AV-0xx ?
One website is reporting AV-048 (047 for Worldview 3?). -
#27 by edkyle99 on 20 Jul, 2014 15:43
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At what point do we stop using those designators if there actually are no more "tail" numbers on the vehicles themselves and if ULA does not use them in its press materials?Does anyone know the Atlas/Centaur tail number for this launch? AV-0xx ?
One website is reporting AV-048 (047 for Worldview 3?).
- Ed Kyle -
#28 by Jim on 20 Jul, 2014 16:53
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At what point do we stop using those designators if there actually are no more "tail" numbers on the vehicles themselves and if ULA does not use them in its press materials?
Because they are used in all engineering documentation. OV numbers were not "on" the vehicles visible to the public. There is a parts tag on the vehicle that does say AV-XXX. T -
#29 by edkyle99 on 20 Jul, 2014 19:15
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But that is the problem. By "we" I mean those of us outside the program, who don't see the engineering documentation. "We" have no way to identify these vehicles. If "we" start guessing, "we" are eventually going to get it wrong, which confuses future historians. Better, I think, to stop guessing altogether.
At what point do we stop using those designators if there actually are no more "tail" numbers on the vehicles themselves and if ULA does not use them in its press materials?
Because they are used in all engineering documentation. OV numbers were not "on" the vehicles visible to the public. There is a parts tag on the vehicle that does say AV-XXX. T
- Ed Kyle -
#30 by Jim on 20 Jul, 2014 20:39
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If "we" start guessing, "we" are eventually going to get it wrong, which confuses future historians. Better, I think, to stop guessing altogether.
Don't need to guess, the info will be provided. -
#31 by edkyle99 on 20 Jul, 2014 23:13
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Much appreciated, but still second-hand for those outside the gate. I would like to see ULA provide the information directly.If "we" start guessing, "we" are eventually going to get it wrong, which confuses future historians. Better, I think, to stop guessing altogether.
Don't need to guess, the info will be provided.
- Ed Kyle -
#32 by vapour_nudge on 21 Jul, 2014 15:00
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SFN references it as AV-048
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#33 by Galactic Penguin SST on 22 Jul, 2014 12:25
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The satellite (SVN68) will be launched into slot F3 to replace GPS IIR-2/SVN43 (launched July 1997); which in turn will be moved to slot F5 to replace GPS IIA-14/SVN26 (launched July 1992; 2nd oldest GPS satellite currently in service).
Source
The satellite's Boeing internal code name is Capella:
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#34 by BabaORileyUSA on 24 Jul, 2014 14:36
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Interesting. The star Capella, means 'Little Goat', and the goat is the animal associated with the constellation Auriga. The ULA mission patch, therefore, is a bit of an anomaly, and my question is simple: which goat at ULA doesn't know the difference between a GOAT and a SHEEP (ram)?!?! The constellation associated with sheep is Aries, but Capella is not in Aries....
I'm just sayin'....
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#35 by Jim on 24 Jul, 2014 16:01
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Interesting. The star Capella, means 'Little Goat', and the goat is the animal associated with the constellation Auriga. The ULA mission patch, therefore, is a bit of an anomaly, and my question is simple: which goat at ULA doesn't know the difference between a GOAT and a SHEEP (ram)?!?! The constellation associated with sheep is Aries, but Capella is not in Aries....
None of these are ULA patches. They are USAF patches.
The top one is the 5th SLS and bottom one is the 45th LCSS. -
#36 by Jim on 24 Jul, 2014 16:03
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The satellite's Boeing internal code name is Capella:
USAF's and not Boeing -
#37 by Galactic Penguin SST on 26 Jul, 2014 23:55
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Per ULA, due to constant delays with the Delta IV launch, this launch will slip to August 1 local time (August 2 GMT - should be 03:23 - 03:41 UTC IIRC).
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#38 by FutureSpaceTourist on 27 Jul, 2014 06:00
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Per ULA, due to constant delays with the Delta IV launch, this launch will slip to August 1 local time (August 2 GMT - should be 03:23 - 03:41 UTC IIRC).
Do we know if there are any range approved back-up slots if it doesn't launch on the 1st? -
#39 by Galactic Penguin SST on 27 Jul, 2014 16:47
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Per ULA, due to constant delays with the Delta IV launch, this launch will slip to August 1 local time (August 2 GMT - should be 03:23 - 03:41 UTC IIRC).
Confirmed by ULA (that is 11:23 - 11:41 pm Eastern August 1).
Here's the mission booklet:
