WAAS PRN 135

From: https://listserv.unb.ca/cgi-bin/wa?A2=ind1012&L=CANSPACE&T=0&O=D&P=47218

"Subject: Galaxy XV WAAS Satellite Could Return to Service
From: Richard B. Langley
Date: Tue, 28 Dec 2010 18:01:15 -0400

Intelsat has reported that they have re-established control over
their
geostationary satellite Galaxy XV (known as FAA WAAS satellite CRW
[=
Central Region West], which operated as PRN 135). The satellite had
been uncontrollable since 5 April 2010 and has drifted from its
assigned orbital slot at 133 degrees west longitude to about 98
degrees west.

By the second week of December, the satellite's reaction wheels had
become saturated with momentum and the satellite could no longer
maintain Earth and sun lock. The deterioration of the satellite?s
ability to remain stable caused intermittent WAAS data link
disruptions that rendered the satellite unreliable for further data
transmissions. Galaxy 15 ceased broadcasting WAAS signals as of 16
December.

According to Intelsat, on 23 December, the power from the Galaxy XV
battery completely drained and the satellite's baseband equipment
command unit reset, as it was designed to do. Shortly thereafter the
satellite began accepting commands and Intelsat engineers began
receiving telemetry.

The satellite is now sun-pointed again, and the satellite?s
batteries
are fully charged.

After completing initial diagnostic tests, Intelsat will load
updated
commanding software to the satellite. They expect to relocate the
satellite to an Intelsat orbital location where their engineers will
initiate in-orbit testing to determine the functionality of every
aspect of the satellite.

Once initial diagnostic testing has been completed, Intelsat will
attempt to capture Earth lock and stop the drifting of the
satellite.
They have reported that this phase could take as long as two weeks
to
complete.

Intelsat have stated that there is a possibility that full
functionality of Galaxy XV could be regained. If that turns out to
be
the case, we might expect to see the FAA resuming WAAS operations
with
the satellite."