Galaxy 7
Begin
|
End
|
Position
|
L:
28 Oct 19992
|
Oct
2000
|
91°W
|
Nov
2000
|
Nov
2000
|
125°W
|
Out
of service
|
22
Nov 2000
|
Cause
|
The
second control processor failed and the satellite was lost. The primary control
processor failed in June 1998. Panamsat should fill a $142 million claim for
insurance.
|
Problems with SCPs in 601 satellites are electrical shorts caused by internal
tin-plated relay latching switches that act as on/off switches within the
processors. Investigators have found that under certain conditions, a tiny,
crystalline structure, less than the width of a human hair, can grow and bridge
a relay terminal to its case, causing an electrical short.
sat-index articles
Specifications
C-band
Ku-band
C-band transponder frequency chart
Ku-band transponder frequency chart
C-band Horizontal
C-band Vertical
Ku-band Horizontal
Ku-band Vertical
The spacecraft was launched using the PVA (
Perigee Velocity
Augmentation) technic. The transfert orbit was 200/27975 km and then the
apogee was upped to 35975 km with the satellite's kick motor and then gradually
circularized.
Vertically polarized transponders are theoretically the only transponders that
can be made into half transponders. Cross-strapping: C-band transponders 18 and
24 can cross-strap to Ku-band transponders 17 and 23.