AMSC 1
American Mobile Satellite Corporation 1
Also called MSAT 2
Operated by
MSV
(successor of Motient Services aka AMSC).
This satellite is a twin of
MSAT 1.
Both satellites were ordered at the same time (with separate contracts). Both
operators will provide complementary mobile telephone, radio, data, and
positioning service to land, aviation, and maritime users. Each operator also
will provide the other with backup and restoration capacity.
While testing a transmission was sent to the satellite which caused certain
components of the communication payload to overheat. The overheating damaged
one of eight output hybrid matrix ports that serve the spotbeams covering the
Eastern and Central United States. The other seven hybrid ports are operating
in accordance with specifications. The remaining four spotbeams, covering the
Mountain and Western portions of the United States, Alaska, Hawaii and the
Caribbean, were not affected. Furthermore, adjustments in the operation of the
satellite will be made to compensate for the power loss.
The satellite experienced in mid-1995, on separate occasions the shutdown of
two solid state power amplifiers (SSPA) serving the Mountain, Central,
Alaska/Hawaii and Caribbean spotbeams. These spotbeams were designed to be
served by eight SSPAs with two spares. As a result of these unusual
occurrences, AMSC is currently operating these spotbeams in a seven SSPA
configuration which preserves one spare SSPA for such spot beams.
Was to be leased to African Continental Telecommunications Ltd (ACTEL) of
Gibraltar through 2003. Cost: $182 million. ACTEL cancelled the lease in 1999.
The license this satellite expired on 31 Dec 2016 and several extensions were
granted to Ligado Networks Subsidiary LLC, now up-to 31 Dec 2024.
Begin
|
End
|
Position
|
L:
7 Apr 1995
|
Nov
2010
|
100.95°W
|
Dec
2010
|
Sep
2018
|
103.3°W
|
Sep
2018
|
Apr
2021
|
106.5°W
|
May
2021
|
|
107.5°W
|
Went
inclined in Nov 2004.
sat-index articles
Prime
contractor
|
Hughes
Hughes (bus) and SPAR Aerospace (payload)
|
Platform
|
HS-601
|
Mass
at launch
|
2550
kg
|
Mass
in orbit
|
1510
kg
|
Dimension
|
2.5
m x 3.5 m x 7.9 m
|
Solar
array
|
20.96
m span
|
Stabilization
|
3-axis
|
DC
power
|
BOL:
3600 W
|
Design
lifetime
|
12
years
|
Springback antennas: 6.7 x 4.9 m x 20 kg (for launch the 2 antennas as rolled
together into a 4.9 m high cone shape atop the satellite)
Main
transponders
|
16
|
Backup
transponders
|
4
|
Power
|
38
W (SSPA)
|
Bandwidth
|
|
Coverage
|
North
America (4 spot beams)
Alaska and Hawaii (1 beam)
Caribbean (1 beam)
|
EIRP
max
|
58
dBW
|
Total bandwith: 3200 x 5 KHz
Each beam transponder is equipped with eight surface acoustic wave filters
covering the 29 MHz L-band allocation, allowing selection of filters to math
traffic needs and to coordinate with other international users. Frequency reuse
is incorporated between the North American east and west beams. The beams are
combined into two L-band power pools, one covering the east and central beams,
and the other covering the remaining service areas. Each power pool is
generated by a hybrid matrix amplifier assembly.
Main
transponders
|
2
|
Backup
transponders
|
2
|
Power
|
100
W (TWTA)
|
Bandwidth
|
24
MHz
|
Coverage
|
CONUS,
Caribbean, Canada, Alaska and Hawaii
|
EIRP
max
|
36
dBW
|
Polarization
|
linear
V
|
Frequencies
|
10.760-10.910
GHz
|
The downlink frenquencies can be mapped to: 10.760, 10.790, 10.820, 10.850,
10.880 or 10.910 GHz.