Sam Wormley
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 Posted: Sat Oct 11, 2008 2:24 am Post subject: Delaying the launch of the Delta II rockets until an indefin |
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GPS Insights — Early October 2008
http://mg.gpsworld.com/gpsmg/content/printContentPopup.jsp?id=556765
Delaying the launch of the Delta II rockets until an indefinite 2009 date is a problem
that needs to be resolved sooner rather than later. The IIR-M satellites designated
IIR-20(M) and IIR-21(M) are critical to the sustainability of the GPS constellation.
Oct 7, 2008
By: Don Jewell
If you follow the progress of the GPS even remotely then you are probably aware that, as
usual, some aspects of the GPS program are on track, but many are not. Therefore, I
decided to go to the ‘source’ for an update.
This month>s column will include an interview with the experts at the GPS Wing (GPSW) and
the Launch and Range Space Wing (LRSW), both from SMC (Space and Missile Systems Center)
at Los Angles Air Force Base (LAAFB), as well as some quick interviews and on the record
comments from several other GPS experts and program officials I have spoken with in the
last few weeks.
Now we face the proverbial coin flip –: do you want the good news or the bad news first?
Let>s start with the not-so-good news first, and that way we can end on a positive note.
As many of you know, the Lockheed Martin (LMCO) IIR and IIR-M birds have been performing
above expectations and have proven to be a very reliable and somewhat autonomous satellite
and payload. And yes, that is good news, but the not-so-good news is that there are two
IIR-M satellites sitting in the barn waiting for a ride into Medium Earth Orbit (MEO) and
they may be waiting for a while. The problems are, there are deadlines to meet and it is
not a good thing for satellites to sit around indefinitely in storage.
Launch Delay
Initially when I received the call from the GPS Wing concerning the IIR-M launch delays, I
was told that the launches would only be delayed a few weeks at most. Those few weeks
became a couple of months, from October to November, and then to December, and now the
date has been pushed out to the Spring of 2009. Now there>s a date you can hang your hat
on – or not. At that point, I decided it was time for a discussion with the experts.
Colonel Madden and the PA folks at SMC, especially Tina Greer, were very obliging, but
because of my travel schedule and the difficulty of getting us all together in the same
place, we accomplished what I like to call an e-interview. I asked the questions and they
answered, all via email. Colonel Madden and I did have a couple of brief conversations and
one face to face as we passed in the night, but the bottom line is, I think I have the
basic facts to relay.
My (DJ) first question to the LRSW was really an unexpected one, I>m sure.
DJ: What exactly is the problem that is causing the launch delay for the IIR-20(M) and
IIR-21(M) satellites?
LRSW: GPS IIR-M missions require a three-stage Delta II launch vehicle. This version of
the Delta II uses timers as part of the ordnance system that controls timing of the third
stage events, including rocket motor ignition and spacecraft separation.
These ordnance timers essentially operate like a burning length of fuse over a [specific]
period of time. The launch delay occurred after a functional test failure in the existing
supply of 40-second timers.
DJ: What exactly is being done to address the fuse problem?
LRSW: As part of the root cause investigation, multiple engineering tests have been
conducted to understand the failure mechanism. We are working closely with the ULA [United
Launch Alliance] to produce a replacement lot of hardware to support the last two GPS
IIR-M launches.
DJ: Will this problem go away after the switch from the Delta II launch vehicle to the
EELV [Evolved Expendable Launch Vehicle] or another way of stating it: is the problem
solely associated with the Delta launch vehicle?
LRSW: The Delta IV and Atlas V launch vehicles do not use ordnance timers. The problem is
only associated with the Delta II launch vehicles.
DJ: Why is the problem just showing up now, at the end of life of the military Delta II
program?
LRSW: The problem occurred during a lot re-qualification test of the remaining inventory
of 40-second timers.
You will notice that the LRSW does not really answer the question. The Wing took this
opportunity to emulate our Presidential candidates and engage in a little political speak.
So why is the problem just showing up now? By way of explanation, the Delta II has been
one of the most successful rockets in the history of the space launch program, and I have
it on good authority that the military three-stage version of the Delta II has always used
these ordnance timers or fuses. They are designed nominally to burn for 40 seconds exactly
and in the past this has always been the case. But sources tell me that recently the
machine that originally crimped these fuses for the last couple of decades ceased to
function and could not be repaired. A new machine using pneumatics crimpers instead of
hydraulics was put in place to produce the fuses and therein lays the real problem. Since
the new pneumatic machine has been put in place, the test fuses have been burning
erratically and that is not a good thing.
My first reaction was that it seems crazy to use a centuries-old technique, a burning fuse
– great shades of the Perils of Pauline on the railroad tracks – but, on the other hand,
it is a technology that until now has been extremely reliable for the Delta II,
three-stage program. But as a senior vice president from a related rocket program told me
the other day, "…… when you make a major change in producing a critical subsystem, in even
the most successful program, your risk factor goes through the roof and you are asking for
trouble, and trouble is exactly what the Delta II program has right now."
I could not agree more, and although the experts at SMC and the ULA (a 50/50 joint venture
between Boeing and Lockheed Martin concerning all launch matters) and others that should
know are all confident that the problem will soon be resolved, and it needs to be resolved
sooner rather than later. The IIR-M satellites designated IIR-20(M) and IIR-21(M) are
critical to the sustainability of the GPS constellation.
You may remember that in an interview with Colonel Madden late last year he made the
statement that several – up to nine, in fact – of the satellites in the current
constellation of 32 satellites are single string, or on their last legs, and could fail at
any time. Indeed, he indicated that although none of the problems were common across the
constellation, the worst-case scenario was that up to nine of them could fail by October 2009.
Now fast-forward about 12 months and the good news is that many of those satellites have
not failed. But what Colonel Madden did not plan on, in his worst-case scenario, is that
the last two IIR-M satellites are in danger of not being launched anywhere near on
schedule. So consequently the 2SOPS is doing everything in their power to keep the current
constellation healthy, but one thing they can>t do is broadcast the L5 coded signal, and
unless the IIR-20(M) with the L5 demo payload is launched and transmitting the L5 signal
by August 26, 2009 the U.S. government loses the allocation for that frequency .
Since many of our future plans for GPS are based on that signal structure and frequency,
this would be a huge blow to the future of the GPS program. Now back to the interview, and
the Launch and Space Range Wing (LRSW) is still answering the questions.
DJ: What exactly are the new launch dates for the IIR-M satellites? The Spring of 2009 is
not very exact. Can you give us a more definitive date?
LRSW: Officially the IIR launch dates are indefinite while the Delta II team works
corrective actions for the third-stage ordnance timer issue.
New launch dates are being coordinated at this time. We expect coordination to be complete
by the end of September [editor>s note: As of October 6 there were still no new dates
announced]. Given this delay, we are taking advantage of the situation to finish some
ground segment testing and operational installations. The program is working diligently to
get the first IIF satellite delivered in early CY09 for final test and launch integration.
IIF launch and IIR-M launches still need to be synchronized. The LRS Wing continues to
assess the schedules for both IIR-20(M) and IIF-1, both hosting an L5 payload, to ensure
the U.S. meets the August '09 International Telecommunications Union (ITU) spectrum
deadline. The Aerospace Corporation performed simulations of the projected lifetimes of
the on-orbit constellation and believe the launch delays will not impact sustaining GPS
services.
DJ: What happens if the launches are delayed further? [editor’s note - the GPS Wing is
answering the questions at this point in the e-interview.]
GPSW: When launches are delayed, the GPS Wing undertakes any contracting options needed to
ensure we can execute the delayed program and assesses operational impacts to determine if
actions are needed to sustain GPS services. We have reviewed the projected lifetime of the
on-orbit satellites and believe the projected delays will not impact service delivery. We
are also monitoring the launch schedules for IIR-20(M), which will carry the L5 demo
payload, and IIF-1, which will carry the operational L5, to ensure the U.S meets the
August 2009 ITU spectrum deadline [editor>s note: Yes, this is redundant, but this was the
official answer].
DJ: What does this do to your contract with LMCO for the remaining IIR birds?
GPSW: Contract actions will be required to extend the Lockheed Martin contract and are
already being defined.
DJ: Since this means a DoD Delta II launch team has to be kept trained and in readiness,
what are the cost impacts to the GPS program?
GPSW: There are expected to be cost impacts. The exact number will be determined by how
much delay will be realized. Lockheed Martin is doing a good job assigning some of their
work force to other programs while waiting for launch processing to continue.
DJ: What are the operational impacts associated with this delay?
GPSW: As we noted before, the GPS constellation is meeting all requirements with more than
the required number of satellites available. The current anticipated delays are not
expected to cause any degradation to those requirements.
Note that, again, this last answer is somewhat ambiguous and does not tell the whole
story. The answer that the constellation is meeting all requirements is not and should not
be comforting. The U.S. government requirement is for 24 satellites and three spares on
orbit or 24+3, although some will still argue that the original requirement was for 21
birds with three spares on orbit or 21+3, and while that may be true the expectations have
ramped-up over the years and 24+3 is now the accepted standard. This means that the
current GPS constellation could be reduced by eight satellites, and the Wing spokesmen
could still make this rather ambiguous statement concerning meeting requirements, but the
war fighters and all the other GPS global users would certainly notice the difference in
service and accuracy. Horizontal, vertical, and position dilution of precision would
certainly change for the worse, because, as I have said many times with regard to the GPS,
numbers and geometry matter.
Although the answers from the Wings were not exhaustive in nature, they do indicate that
they are working the fuse problem hard and evidently just don>t have any more definitive
answers as yet. But time is getting short, and every day puts us that much closer to
loosing the L5 frequency allocation.
I also spoke with the Julie C. Andrews, from the ULA (no not that Julie Andrews, although
she does have a very nice telephone voice) and she reassured me that "mission success is
the number one priority at ULA, and getting the Delta IIR-M satellites launched
successfully is something everyone at ULA is working hard to accomplish. "
I asked her about the recent Delta II launch of the GeoEye satellite, which occurred on
September 6th, 2008, after the fuse problem had been discovered, and she explained that
the particular Delta II version used in that launch was a civilian version of the rocket
that uses a different technology – and not three stages, so in other words, no fuse
problems because they don>t use them. The same will go for the COSMO-3 Delta II launch
coming up later this month. Since neither the civilian nor NASA Delta II variants use the
fuses causing the problems for the military three stage version, the Delta II launch
record should remain safe for now.
With regard to the string of successful launches, I also mentioned to Colonel Dave Madden
and others that we have had more than 60 successful launches since the bad old days when
we had several launch failures in a row and put hundreds of millions of dollars worth of
rockets and satellites in the drink. My point being that if he thinks his programs have
too much Congressional and DoD oversight now, all he has to do is have a launch failure
and destroy a perfectly good GPS satellite, then he will have more attention and oversight
than even he can stand. Plus, with everything else going on in the Air Force right now, a
launch failure is the last thing they need.
And as for the Wings' depending on the first Boeing IIF launch to save their bacon
concerning the L5 frequency allocation, that is disconcerting as well. I will not dwell on
how late and how much over budget the Boeing IIF program is, but suffice it to say that it
is embarrassing for everyone involved. If the Boeing IIF program were not the only option
currently available, it would have been cancelled years ago, but it is the best we have
right now, and we need to all get behind the program and support it.
But I have serious doubts about the IIF being launched in time to save the L5 frequency
allocation. I sincerely hope I am proved wrong and I will happily admit it when it
happens, but at the same time I am not holding my breath. The IIF has still not been
through full thermal vacuum testing, and that should have been accomplished more than six
months ago. Granted, a lot of the problems can be laid at the feet of Boeing>s
subcontractors, but then that is why prime contractors are paid the big bucks. And Boeing
has been paid big bucks and has had numerous contract/program extensions. Rumor has it
that Boeing may loose money with every IIF launch, and if they know that now, before the
first bird has even left the ground, then you have to lay it at the feet of Boeing
management. Enough said. I hope and pray Boeing proves the naysayers wrong. In fact that
would be fantastic news and I would be among the first to report it that way.
Now Back to the Good News
As for the current Lockheed Martin IIR and IIR-M satellites and payloads, longevity does
not seem to be an issue with these birds, and the crews at Schriever AFB are more than
satisfied with the satellites' and payloads' performance. The mean GPS accuracy is
literally getting better everyday, and there have not been any across-the-board subsystem
failures, which is always a good thing. The clocks are proving to be accurate and reliable
and generally require fewer updates than past generations of clocks, although the 2 SOPS
continues to perform updates on a rigorous schedule in order to provide the best possible
signal for our warfighters.
On an added note, I am sure most of you noticed that GIOVE-B, the second test satellite
for Galileo, was shut down for a period of 15 days because of radiation problems. The best
rumor to date is that the hydrogen maser test package and control system succumbed to a
single event upset caused by a spike of radiation. We are actively trying to determine
exactly what happened and will let you know as soon as we do. There is certainly a lot of
expertise on hardening of space electronics among U.S. manufacturers; I wonder if the
Galileo program is suddenly in the market for that expertise? But I digress … back to the
U.S. GPS program.
I spoke recently to Dr. Don DeGryse, the VP of Navigation Systems for Lockheed Martin, who
is in charge of the GPS III program for LMCO and he tells me that everything is currently
on schedule and there are no foreseeable showstoppers. He will know more after a milestone
review, called the Integrated Baseline Review or IBR, that takes place later this month,
and then he and I will talk again, and I will be able to give you a more definitive update.
So the bottom line is that as I write this column we have 32 GPS satellites on orbit with
a spare that can be brought online as needed. Satellites have not been failing at the
projected worst-case rate scenario and there are two more ready to go, plus the next
generation (GPS III that is) is on time and on schedule.
What more could you ask for?
Don>t get me started. Until next time, happy navigating. |
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