Welcome Lucianne Readers – and I am not yet a ‘former’ NASA contractor!

Update – some bloggers linking here have wondered if I work for NASA – and the answer is yes (as a contractor).  Here’s a good overview of the GPS system. Cheers, AJStrata – end update

You know it is really hard to tolerate rank amateurs when they go around screaming ‘fire’ because they don’t have a clue what a fire actually is. Case in point, the alarm bells being rung over a supposedly failing GPS network:

US government officials are concerned that the quality of the Global Positioning System (GPS) could begin to deteriorate as early as next year, resulting in regular blackouts and failures – or even dishing out inaccurate directions to millions of people worldwide.

What a pile of horse-hockey. What this is a prime example of reporting on a mildly complex subject with a massive amount of ignorance and incompetence. The GPS service is not really all the complicated to grasp, but apparently it was too much for these fools.

First let me explain the system in terms a high schooler could probably grasp. Each satellite broadcasts a signal that contains its position and a time marker. GPS receivers pick this broadcast up just like your car radio picks up an AM station. The difference is the time sync code.

The receiver can determine the time delay from the broadcast to reception. If you do this from 3-4 different satellites at any given time your receiver clock is synchronized to the universal time standard with incredible precision, and the 3-4 time delays and the orbital position data in the signal allow the receiver to triangulate its position.

You don’t always need 3-4 because once a position and time is fixed it can interpolate for quite a while on only 1-2 satellites. To get an ‘outage’ requires long delays without 2 or more satellites. You can (and you do) go down to 2 satellite signal for a good period of time before the receiver starts losing its position knowledge.

Now, the minimum number of satellites required to provide global coverage of 3-4 satellites at any given time with manageable ‘outages’ is 24 satellites. Guess how many satellites are up there now?  31. To go below the minimum and barely begin to degrade most commercial users requires the GPS system to lose 25% of the satellites. That won’t happen in one year, and won’t happen in 10 years.

The GOA report is a lot of bureaucrat hyperventilating. It seems to be part technical ignorance, but also could have a dash of the Obama administration searching for another faux emergency to come riding to the rescue over. Most of the whining is cost overruns:

In recent years, the Air Force has struggled to successfully build GPS satellites within cost and schedule goals; it encountered significant technical problems that still threaten its delivery schedule; and it struggled with a different contractor. 

There is plenty of spare capacity stored on orbit to handle the delays. What is bugging GOA is the fact the first contractor screwed up and the 2nd is struggling. Here is the essence of the delay:

… the launch of its first satellite has been delayed to November 2009—almost 3 years late.

If it is launched in November, even if we lose 1 satellite there are 6 spares on orbit. Sound the alarm bells!

A closer read shows this is not about the GPS II series, but the start of the GPS III replacement series:

… the Air Force is structuring the new GPS IIIA program to prevent mistakes made on the IIF program, the Air Force is aiming to deploy the next generation of GPS satellites 3 years faster than the IIF satellites.

…

If the Air Force does not meet its schedule goals for development of GPS IIIA satellites, there will be an increased likelihood that in 2010, as old satellites begin to fail, the overall GPS constellation will fall below the number of satellites required to provide the level of GPS service that the U.S. government commits to.

Actually there is only the slightest chance between now and 2010 6 satellites will fail. It is extremely UNLIKELY (take it from someone who lives and breathes satellites). This is completely false. 

But the GPS III series has NOTHING to do with the remote possibility of a cascade of never before seen failures across multiple spacecraft. There is no way to move up the series III development – none. But there is always the classic fall back of building more series II birds. 

These satellites are based on commonly used commercial spacecraft buses. It is the payload that is unique to GPS. There are always ways to take order of another copy of the bus being used for the series for national safety reasons. The GOA report doesn’t seem to know this (or care to share it with the public).

But the important detail in the report is the fact the first Series IIF launch is in November, not the first Series III launch or the last Series IIF launch. Just the first of many new birds coming on line.  The current Series IIF launch schedule shows 12 new satellites being launched between November 2009 and mid 2012. Not one, 12!

We have 7 extras on orbit and 12 news Series IIF in the pipeline and these knuckleheads cry ‘fire’? And they claim it is a delay in the Series III program – which is still on the drawing board and years away from its first launch – that will cause interruptions in 2010?

Folks, someone should be fired over this false alarm. Seriously.

Update: GPS Series III is not scheduled for its initial launch until 2014 – so there is no way Series III could effect the 2010 system availability. – end update

Addendum: I cannot believe how much traction this completely bogus report is getting in the news media. Does ANYONE fact check anymore? Here’s the deal with satellite design life. Voyager I and II were LAUNCHED in 1977 – over 30 years ago! Their ‘design life’ was probably around 5-7 years. That’s the minimum required, not what will happen.

These GPS birds (and their COMSAT cousins) are designed for 10-12 20 years minimum, which means ALL of them should reach that mark. But to do so means they will last – on average – well beyond that. Many of today’s work horse satellites can do 15-20 years if fuel permits. Some fail early, but most don’t.

GPS satellites will not be failing en masse next year my dear Shepard Smith – that’s not the way it works.

Update 2: This is just plain ridiculous:

SATNAV systems used by millions of motorists could become useless next year, it was claimed last night.

Experts warned that the Global Positioning System, which sat navs rely on, could collapse due to a lack of investment in new satellites.

The first replacement satellite had been due to be launched into space in 2007 but will not now be ready until November.

I repeat. There are 7 spares on orbit. They will not all fail before November. I doubt more than one would. But by mid 2012 there will be 12 spanking news ones on orbit. The people behind this report are not ‘experts’ by any stretch of the imagination. And the so called ‘experts’ claimed the Series III – due to launch start launching in 2014, are the reason we will lose GPS services next year. Anyone know the difference between 2010 and 2014! And people wonder why the news media is going out of business? 3rd graders could do a better job of reporting.

Pathetic.

Tags: False Alarm, GPS Network