backtop


Print 24 comment(s) - last by inperfectdarkn.. on May 22 at 12:57 PM

The US Air Force needs to act now, report says

There is growing concern that the current global positioning system network of satellites used by the United States is aging and will begin to routinely fail starting in 2010, a Government Accountability Office (GAO) report indicates.

The U.S. Air Force now uses 30 different GPS satellites -- which launched into orbit in the early 1990s -- and has become noticeably less reliable and may be sending inaccurate navigational information to people using mobile GPS units.

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," the GAO's "Global Positioning System: Significant Challenges in Sustaining and Upgrading Widely Used Capabilities" report claims.

The US government is expected to invest almost $6 billion into new GPS satellite technology over the next four years, in an attempt to try and get back on schedule after suffering several years of "significant" technical issues.  If the Air Force is unable to get back on track, however, the GAO warns there could be wide-ranging ramifications for all GPS users.

As there is growing concern regarding GPS, Boeing recently lost a lawsuit that would have prevented the Air Force from disclosing Boeing GPS satellites cost.  Boeing believes Lockheed Martin, the company's biggest competitor, may be behind the request, which was filed several years ago under a Freedom of Information request.

A few years ago only specialized GPS units made use of GPS, but now many mobile phones and smartphones now utilize the technology for consumers to enjoy.  Furthermore, an even larger number of new cars are shipping from the factory with built-in GPS units.

However, there is a much larger concern regarding possible intercontinental flights being canceled or delayed, and the military's reduced amount of "smart bombs" for use in Afghanistan.

It should be interesting to see if the Air Force is able to straighten out budget issues and make sure there isn't a serious GPS gap in the coming years.  Military officials said its IIIA block of satellites will be launched three years earlier than planned, but the GAO report said it's "optimistic given the program's late start, past trends in space acquisitions, and challenges facing the new contractor."



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: Definite problem
By Shadowself on 5/20/2009 10:19:09 AM , Rating: 4
They've launched GPS satellites since 2000. Anyone can look that up and verify that. The satellites currently up there have most definitely *not* been up there since the early 90s!

You need four satellites to get a proper fix. Three for the physical calculation and one more for time relevance (all the calculations are based upon time). In theory, if your receive from more satellites than four you can get a slightly better fix.

You need to be able to "see" a minimum of four satellites to get a fix. Even if there are only four satellites and not 24 IF all four are over you at one time you can get a fix. In fact, the "Initial Operational Capability" of the GPS system was declared before they had 24 fully operational satellites in orbit.

Additionally, as I've said, they don't "use" 30 satellites at a time. The operational constellation has 24 satellites with six on orbit spares.


RE: Definite problem
By BadCat351w on 5/20/2009 2:01:53 PM , Rating: 3
Thanks for the info, but maybe you should take your own advice and look up the info,
http://en.wikipedia.org/wiki/Global_Positioning_Sy...
quote:
Since it became fully operational on April 27, 1995


RE: Definite problem
By openair on 5/20/2009 2:19:46 PM , Rating: 2
READ... From your own link.

"By December 1993 the GPS achieved initial operational capability.[11]
By January 17, 1994 a complete constellation of 24 satellites was in orbit."


RE: Definite problem
By BadCat351w on 5/20/2009 2:27:10 PM , Rating: 2
What I posted was one factual line stating when it was fully operational, thus pointing out that it has been fully operational long before 2000, there are many dates in the article with different outcomes going back to 1960, it was a reference, you want me to list all dates? No, you can do that,


RE: Definite problem
By openair on 5/20/2009 2:53:04 PM , Rating: 2
Ahh, I see. But of course it has. The op doesn't say otherwise. He mearly said that they have already replaced many satellites over the past 20 years.


RE: Definite problem
By jhb116 on 5/20/2009 5:10:54 PM , Rating: 2
You also inaccurately quote 24 versus 30. 24 is the minimum number required (evenly spread over a number of orbital planes) to provide 24/7 global coverage. The system is actually able to use up to 30 satellites for active use by consumers. If the wiki link is accurate - there is one stand-by spare (31 satellites).

The GAO report is probably alluding to the fact that probably more than half the constellation is past the design life and/or a large number of satellites might be what is referred to as a single point of failure away from becoming inoperable.


"This is from the DailyTech.com. It's a science website." -- Rush Limbaugh











botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki