GPS NAVIGATION SATELLITE SET FOR LAUNCH THIS AFTERNOON
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Boeing's workhorse Delta 2 rocket is scheduled for launch at 2:50 p.m. EDT
(1850 GMT) this afternoon from Cape Canaveral, Florida. The booster will
loft a fresh satellite for the Global Positioning System. Follow the
countdown in our live Mission Status Center:

http://spaceflightnow.com/delta/d318/status.html

QUICK-LOOK FACTS:

http://spaceflightnow.com/delta/d318/cuecard.html


Delta 2 Rocket to Launch GPS Satellite Today

http://www.space.com/missionlaunches/delta2_gps2r15.html

Clocks have entered the final five hours in the countdown to today's liftoff of
the Boeing Delta 2 rocket and the GPS 2R-15 spacecraft.

UPDATING THE GPS SATELLITE NETWORK TAKES NEXT STEP
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One year to the day after the Global Positioning System constellation
began a modernization effort to improve the accuracy of the navigation
network, the next step in that upgrade blasted into space from Cape
Canaveral, Florida.

http://spaceflightnow.com/delta/d318/

LAUNCH PHOTO GALLERY:

http://spaceflightnow.com/delta/d318/060925launch/01.html

Solar flares cause GPS failures, possibly devastating for jets and distress calls, Cornell researchers warn

http://www.news.cornell.edu/stories/Sept06...res.gps.TO.html

Yeow...well, that's why LORAN-C is still around for maritime navigation. Back in the 90s the sea-based industries balked at the idea of a sole-source nav aid, and in retrospect this seems quite prudent. Might be smart for aircraft to follow suit.

a small INS can fix this.

True...but INUs and their peripheral equipment are very expensive in comparison to commercial LORAN receivers. Most ships have a directional gyro as their only stand-alone navaid, hence the pressure to keep LORAN-C functional...a testimony to the power of long-established protocols with respect to economics, 'cause commercial shippers want to make money & hate expensive infrastructure investments.

There are lots of ancillary installation issues to consider for INSs on ships...for example, determining the "true position" offset with respect to the INU location can be problematic on large vessels, which adds cost for both the site survey work and software sustainment as ship configurations change (which they always do). Heck, I suggested equipping the NOAA fleet with INSs back in the day, and was told that they couldn't afford it! (Hint, hint, for any INS developers out there...a cheap, reliable INU with simplified, adaptive installation techniques for commercial shipping with standard interfaces like NMEA-0183 might do very well on the open market).

FYI...I sailed on NOAA research ships in the '90s as an electronics technician, so I had some very direct experience with this mess...suffice to say that only the military was able to afford INS at that time, probably because they practiced far more rigorous vessel configuration control.

I'm not disputing your expertise in this but MEMS based INS systems are an area of heavy investment and R&D due to their increasing use as GPS assistance systems for in car navigation. See here for an example of a button sized solidstate rate gyro.
The state of the art might not be quite hitting the right cost\performance point to be perfect but it is rapidly converging on it.

Very cool indeed!!! Well, it looks like INS for the masses might well become a reality soon; it's about time.

I'd love to see INUs small & cheap enough so that even light aircraft could be equipped with at least quintuply-redundant systems. This would provide enough fault tolerance to enable a LOT of cool guidance and control applications...