Galaxy 4
Also called HGS 4
A fuel cell rupture occured (approx. 22:20 UT on 19 May 1998). The attitude
control and backup failed. The satellite was declared a total loss on 20 May.
Insurance paid $165 million.
The failure affected millions of pager accross the US.
Galaxy 6
was preempted to replace the satellite.
Out
of service
|
20
May 1998
|
Cause
|
failure
|
HGS would have found a customer to use the limited capabilities the satellite
still has.
sat-index articles
Specifications
C-band
Ku-band
C-band transponder frequency chart
Ku-band transponder frequency chart
Galaxy 4 also has a special footprint in Ku-band for Hawaii (44 dBW), Alaska
(40 dBW) and Puerto Rico (44 dBW), but only for some vertical transponders.
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.
Launched using the PVA (
Perigee Velocity Augmentation) technic. The
transfert orbit is 200/27975 km and then the apogee is upped to 35975 km with
the satellite's kick motor and then gradually circularized.