[Kenneth P. Katz]

This is double-plus bad.

The Wall Street Journal
June 18, 2009
GPS Satellite Glitches Fuel Concern on Next Generation

By Andy Pasztor

Technical problems are degrading the accuracy of signals from the last GPS satellite launched by the Pentagon, sparking concerns among U.S. military and aerospace industry officials that the next generation of the widely used satellites could face similar troubles.

The Air Force's Southern California space acquisition center on Tuesday announced that a Global Positioning System satellite, manufactured by Lockheed Martin Corp. and launched in March, is experiencing performance problems in orbit. It hasn't become part of the "operational constellation" of more than two dozen other GPS satellites, and is slated to undergo a battery of tests expected to stretch through October to try to resolve the problems, according to an Air Force news release.

The GPS system, which serves both military and civilian users, provides precise time and location coordinates for everything from military missile launches and "smart" bombs to automated bank-teller machines to aircraft, ships and everyday vehicles. The Lockheed satellite is the first to include a new civilian frequency -- dubbed L5 -- designed for, among other things, use by future nationwide air-traffic control systems. But that signal, part of test package, apparently is interfering with other signals from the satellite and reducing their accuracy, according to industry and Air Force officials. The degraded signals are accurate only to about 20 feet, versus about two feet for typical GPS signals, industry officials said.

The issue is significant, according to these officials, because it could complicate deployment of a new family of Boeing Co. GPS satellites currently being built that also feature the L5 signal. Already years behind schedule and hundreds of millions of dollars over budget, the 12 satellites, which are scheduled to replace satellites currently in orbit, could face further testing and delays to ensure that they are free of interference problems. The Boeing satellites have a history of quality-control and manufacturing problems unrelated to the latest concerns.

While the Air Force said it has "high confidence there is no related concern" with other Lockheed satellites in orbit or waiting for launch, Air Force brass have begun examining whether Boeing versions of GPS satellites require additional tests and analysis to eliminate concerns, according to industry officials familiar with the details. A spokeswoman for Boeing declined to comment. A Lockheed Martin spokesman said the company is working with the Air Force "to fully evaluate the issue and to ensure the satellite meets GPS requirements."

In its release, the Air Force said the routine in-orbit checkout of the suspect Lockheed satellite revealed that some signals "were inconsistent" with comparable GPS satellites. The Air Force also said upcoming tests will include simulations and "testing of real-life GPS receiver equipment to the greatest extent possible" to prevent "inadvertent impacts to GPS users."

The first of Boeing's GPS IIF satellites, incorporating the new civilian signal, is slated to launch late this year or early 2010, delayed from the summer.

In May 2008, Lockheed bested Boeing to win a contract worth at least $1.8 billion to build the most-advanced navigation satellites yet, dubbed GPS III, scheduled to go into operation around the middle of the next decade.

Concerns over signal quality come barely weeks after a Congressionally-ordered study raised a red flag about potential erosion of GPS accuracy in the next few years due to launch delays and other challenges. If certain launches get delayed up to two years, the General Accountability Office report predicted, the Pentagon could have trouble maintaining the desired fleet of 24 fully-functional GPS satellites in operation.

The Pentagon responded by minimizing the potential risk, arguing that significant spare capacity remains on orbit and on the ground to handle unexpected problems. Gen. Robert Kehler, head of Air Force Space Command, said in an interview earlier this month that the GAO conclusions were overly pessimistic partly because they failed to take into account strategies the Air Force could use to extend the life of existing satellites. For example, Gen Kehler said, managing power output could give solar arrays longer life.

Despite some continuing quality-control issues with Boeing's IIF versions, Gen. Kehler said, "we're not going to have an issue" maintaining the current robust constellation.

[shep854]

Huh. Map & compass, anyone? :rolleyes:

[aevans]

Kenneth P. Katz, on Thu 18 Jun 2009 0301, said:

This is double-plus bad.

A single Lock-Mart spacecraft has an unexpected performance problem on-orbit. The program very prudently orders a review of the potential for the same problem on unlaunched spacecraft of both Lock-Mart and Boeing manufacture. It's a delay. It's a frustration. These things happen.

[Kenneth P. Katz]

The GPS constellation needs to be replenished. This problem will delay that replenishment. And just based on the article, this seems like the kind of problem that should have been found during ground testing. So a large pot of $$$ may have been squandered. That's pretty bad by any reasonable standard.

aevans, on Thu 18 Jun 2009 1541, said:

A single Lock-Mart spacecraft has an unexpected performance problem on-orbit. The program very prudently orders a review of the potential for the same problem on unlaunched spacecraft of both Lock-Mart and Boeing manufacture. It's a delay. It's a frustration. These things happen.

[Mike Steele]

shep854, on Thu 18 Jun 2009 0636, said:

Huh. Map & compass, anyone? :rolleyes:

Rapidly diminishing skill.

[aevans]

Kenneth P. Katz, on Thu 18 Jun 2009 1609, said:

The GPS constellation needs to be replenished. This problem will delay that replenishment. And just based on the article, this seems like the kind of problem that should have been found during ground testing. So a large pot of $$$ may have been squandered. That's pretty bad by any reasonable standard.

If worse comes to worst, they launch the birds in time to replenish the constellation and never activate the L5 channel. This would be a graceful fail from a nominal capability set to an acceptable, if less than desired, capability set. No catastrophe involved.

If the worst doesn't come, they fix the problem and carry on.

[Tuccy]

shep854, on Thu 18 Jun 2009 1436, said:

Huh. Map & compass, anyone? :rolleyes:

We don't need no stinkin' compasses! Atleast not here in the Central Europe where village density is high enough that it's usually enough to walk an hour to get exact fix by village name ;)

[Jason L]

Quote

Huh. Map & compass, anyone?

Ever try to consult a map and compass travelling 40 kph on a bike? My GPS tracks elevation and grade data as well.

[shep854]

Jason L, on Thu 18 Jun 2009 1349, said:

Ever try to consult a map and compass travelling 40 kph on a bike? My GPS tracks elevation and grade data as well.

Yep, land nav skills are dying, if folks have forgotten how to stop periodically to check location and direction... :) There are also the times the GPS database is wrong. I've had this happen a time or two with the GPS in my car. Yes, I do keep maps handy.

When I was a Mission Pilot with the Civil Air Patrol, it was fun to turn off the GPS and watch the observer quietly freak while he struggled with map and plotter to determine position and direction--which he should have prepared for as part of his mission prep.

[Jason L]

Quote

Yep, land nav skills are dying, if folks have forgotten how to stop periodically to check location and direction...

The whole point is not stopping, your heart rate drops, your legs cramp up, etc. Also the GPS stores detailed ride data so I can see how I did during various climbs, etc.

Carrying a detailed map on a bike when you aren't touring is a pain in the ass too.

[Kenneth P. Katz]

Not sure how that works in a Predator or a JDAM.

shep854, on Thu 18 Jun 2009 1236, said:

Huh. Map & compass, anyone? :rolleyes:

[Sikkiyn]

shep854, on Thu 18 Jun 2009 1444, said:

When I was a Mission Pilot with the Civil Air Patrol, it was fun to turn off the GPS and watch the observer quietly freak while he struggled with map and plotter to determine position and direction--which he should have prepared for as part of his mission prep.

Your observer was not familiar with a compass, sectional chart, and NBD/VOR?

Simple enough to figure out where you are at without having Magellan.

[aevans]

Sikkiyn, on Thu 18 Jun 2009 2036, said:

Your observer was not familiar with a compass, sectional chart, and NBD/VOR?

Simple enough to figure out where you are at without having Magellan.

VFR = Visually Follow Roads

IFR = I Follow Roads

[Jeff]

shep854, on Thu 18 Jun 2009 1544, said:

There are also the times the GPS database is wrong. I've had this happen a time or two with the GPS in my car. Yes, I do keep maps handy.

Ditto

[shep854]

Don't get me wrong; I looove GPS! :wub: I do courier work and if it weren't for my GPS, I probably would still be wandering around New Orleans, from a visit a year and a half ago!

As awesome as the things are though, backup is comforting.

Besides, using a map gives another incentive to look at the surroundings.

This post has been edited by shep854: 18 June 2009 - 1703 PM

[shep854]

Sikkiyn, on Thu 18 Jun 2009 1536, said:

Your observer was not familiar with a compass, sectional chart, and NBD/VOR?

Simple enough to figure out where you are at without having Magellan.

The scary thing is that too many pilots are depending on "Direct To" and ignoring (& forgetting) pilotage and ded reckoning. A friend who is an active pilot tells me that he is seeing these skills being neglected in flight training.

[swerve]

Jason L, on Thu 18 Jun 2009 2050, said:

The whole point is not stopping, your heart rate drops, your legs cramp up, etc. Also the GPS stores detailed ride data so I can see how I did during various climbs, etc.

Carrying a detailed map on a bike when you aren't touring is a pain in the ass too.

My bike GPS (a birthday present from Naomi-chan) uses Ordnance Survey map cards. I therefore have a detailed map, with my position marked, & any route I've loaded shown overlaid on the map, sitting on my handlebars. Also good for walking.

[shep854]

swerve, on Thu 18 Jun 2009 1811, said:

My bike GPS (a birthday present from Naomi-chan) uses Ordnance Survey map cards. I therefore have a detailed map, with my position marked, & any route I've loaded shown overlaid on the map, sitting on my handlebars. Also good for walking.

Are you able to access the maps if the GPS goes down?

[TomasCTT]

Whilst I agree that map reading and using a compass are important skills that still should be learned, still like what Kenneth said: JDAM and other GPS-guided ordnance and UAVs won't be able to work just as well without GPS (they sure can't fold out a map and bring out a compass as they hurtle towards the target).

[wallaby bob]

[quote name='shep854' date='Thu 18 Jun 2009 2318' post='681983']
Are you able to access the maps if the GPS goes down?
[/quote

ALL. This discussion evokes memories of navigating with a map ,and compass, only in pre-GPS days. Mention of no problems in closely settled areas may be alright in areas where one is fluent in the local l;anguage and script. Not everyone uses a Latin script.I can recall being almost totally unaware of my, our , location in Japan on a map reading exercise in japan due to the great multiplicity of towns/villages in a relatively small area until we came on a town where the Post Office was signposted in English or at least the Latin script.Alternately it may have been Romagi the Japanese rendering of the Latin alphabet..
And again in Seoul one morning when looking around the city on my own this time a fog descended. My knowledge of Korean being even more lamentable than my skills in Japanese scripts.
I thought I might mention that there are at least two(2) other global positioning networds availabe in orbit and working the European and the Russian Glonass. Their use might not be politiacally desirable. WB