The Federal Aviation Administration (FAA) announced (on April 30) that
one of the two WAAS GEO satellites will drift out of usable orbit
within two to four weeks.

Earlier on April 8th, Intelsat announced it had lost control of its
Galaxy 15 satellite that hosts the WAAS SBAS transponder used by the
FAA.

The FAA says it is monitoring the satellite, but that failure is
imminent (by mid-May 2010).

When G-15 is out of usuable orbit, WAAS will be disrupted for users in
northwest Alaska.

The rest of the WAAS service area — U.S., Canada, Mexico — will
operate normally but will be reduced to a single point of failure with
only one WAAS broadcasting Anik F1R satellite remaining (PRN #138/
NMEA#51).

The impending failure of this satellite—which only affects WAAS signals
—comes at a time when there are questions about the regular GPS
constellation. The U.S. Government Accountability Office has said that
many of the older satellites currently in use could reach the end of
their operational life faster than they can be replenished, resulting
in a drop below the number of satellites needed to meet some GPS
users’ needs, as early as this year.

http://blog.geogarage.com/2010/04/wa...oing-down.html