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GLOBALSTAR
 The
Space Systems Loral 'Big LEO' global mobile communications network offers global, digital
real time voice, data and fax via a constellation of 48 minisatellites. More than
10 major companies have invested US$2.6b (1998), and include Loral (39%), Qualcomm inc.,
AirTouch communications, Alcatel, DACOM, Daimler Benz Aerospace, Hyundai, Elsacomm, China
Telecom (HK), Vodaphone and France Telecom.
Artist impression (right) courtesy of Space Systems Loral
  The
constellation operates in a 1410km orbit inclined at 52 degrees, and will also have 8
spares. The satellites were built by Space Systems Loral and Alenia Aerospazio in Rome,
Italy.
  Pictures show the LS-400 LORAL/Alenia platform body is trapezoidal in
shape with two deployed solar panels, in order to allow multiple satellites to be carried
on the same launch. The satellite is 3-axis stabilised and employs magnetometers on a
deployable boom, sun sensors, GPS as attitude sensors, and carries two deployable solar
arrays delivering 1100W for normal operations. The propulsion system employs hydrazine,
and its primary use is station keeping. Each satellite weighs 450kg, with a dry mass of
350kg, and is designed for a 7.5 year lifetime. The payload antennas are phased arrays
mounted on the satellite body. The Attitude control, orbit control and solar panels were
delivered by Dornier (Ger).
  Globalstar has launched using DELTA,
Zenit, and Soyuz Ikar.
Spacecraft are operated from a San Jose Ca. control centre, and more than 60
further station(incl telemetry command unit gateways located in Aussaguel, France; Yeoju,
South Korea; Dubbo, Australia; Bosque Allegre, Argentina; and Clifton, Texas.) support the
system as gateways. Fixed and vehicle mounted terminals are supported by the system, as
well as standard hand-held phones.
The first 4 spacecraft were built in an 18 month schedule.
   The third launch failed leading to a US$190m
insurance claim. A picture shows the launch configuration.
The launch configuration for the Soyuz is shown to the right.
Operational service was started in the third Quarter of 1999.
Frequencies
  The
spacecraft employ secure links to control station (C-band 6875-7055MHz), and handsets (16
cells L-band 1610-1626.5MHz up, 16 cells S-band 2483.5-2500MHz down). CDMA is employed,
and data rates of up to 9600bps are supported on terminals.
Gateways cover a radius of approximately 2000km.
Orbits
Spacecraft are launched into a 1420km circular orbit inclined at 52 degrees.
Launch record
|
FM |
In orbit |
Launch date |
Launcher |
Site |
Initial Orbit |
ID's |
Comments |
| 1 |
1-4 |
4 |
14Feb98 |
DELTA-II |
Cape Canaveral |
1245x1258km |
U1, U2, L1, L2 |
|
| 2 |
6, 8, 14, 15 |
8 |
24Apr98 |
|
|
|
|
|
| 3 |
5, 7,9,10-13, 16-18,
20,21 |
8 |
9Sep98 |
Zenit-2 |
Baikonur Cosmodrome |
N/A |
|
Launch failure |
| 4 |
23, 36, 38,40 |
12 |
9Feb99 |
Soyuz-Ikar |
Baikonur Cosmodrome |
950km |
|
|
| 5 |
22, 41, 46, 37 |
16 |
15Mar99 |
Soyuz-Ikar |
Baikonur Cosmodrome |
952x910km |
|
|
| 6 |
19,42,44,45 |
20 |
15Apr99 |
Soyuz-Ikar |
Baikonur Cosmodrome |
897x950km |
|
|
| 7 |
25,49,47,52 |
24 |
10Jun99 |
DELTA-II |
Cape Canaveral |
1370km |
|
|
| 8 |
32, 30, 35, 51 |
28 |
10Jul99 |
DELTA-II |
Cape Canaveral |
185x1367km |
|
|
| 9 |
26, 28, 43, 48 |
32 |
25Jul99 |
DELTA-II |
Cape Canaveral |
|
|
|
| 10 |
24, 27, 53, 54 |
36 |
17Aug99 |
DELTA-II |
Cape Canaveral |
|
|
|
| 11 |
33, 50, 55, 58 |
40 |
22Sep99 |
Soyuz-Ikar |
Baikonur Cosmodrome |
|
|
|
| 12 |
31,56,57,59 |
44 |
18Oct99 |
Soyuz-Ikar |
Baikonur Cosmodrome |
|
|
|
| 13 |
29,34,39,61 |
48 |
22Nov99 |
Soyuz-Ikar |
Baikonur Cosmodrome |
|
|
|
| 14 |
|
|
8Feb2000 |
DELTA-II |
Cape Canaveral |
|
|
|
In 2001 it was reported that 2 spacecraft had failed due to intense solar
activity.
References
More...
[loral SS][Alenia]
[Satellite description at Globalstar][Description
of Globalstar][Lloyd Wood's Big LEO pages at CSER]
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