Two
Space Systems/Loral (SS/L) satellites with the highest capacity
of any commercial payloads in space were delivered on orbit in
1995 and 1996 and are now providing a variety of fixed and mobile
domestic communications services to customers throughout Japan.
These satellites, N-STAR-a and -b, replace the service of the
SS/L CS satellites, which have now exceeded their expected lifetimes,
and will also provide significant new services, which range from
providing alternate routes for telephony, to emergency communications,
to marine and terrestrial mobile services, and ISDN.
The N-STARs were built for Nippon Telegraph and Telephone (NTT)
and NTT Mobile Communication Network Inc. (NTT DoCoMo). Dubbed
“switchboards in the sky,” for their wide range of
abilities, these 26 transponder satellites each carry five separate
communications payloads operating in four frequency bands:
The S-band payload provides terrestrial and maritime mobile communications
services in four S-band antenna beams via a radio frequency feeder
link at C-band. Dual mode phones enable users to connect to either
conventional cellular or satellite service.
The Ka-band multibeam payload provides satellite switched time-division
multiple-access (SS-TDMA) communications for the main Japanese
islands and Okinawa. This payload is a dynamic switch, program-mable
by commands from telemetry uplinks to switch traffic from any
of eight uplink beams into any of three downlink beams as needs
and conditions change. The Ka-band shaped-beam payload provides
five 100-MHz wide channels, operating as a conventional turnaround
repeater.
The C-band payload provides six 72-MHz channels, one of which
serves as a dedicated feeder link for the S-band mobile system.
The Ku-band payload provides eight 54-MHz channels, each using
a high-power TWTA as its final amplifier. One of the channels
serves as a backup to the C-band feeder link for the S-band mobile
system. In N-STAR, SS/L delivered a turnkey package on orbit
that included design and construction of the satellite, procurement
of launch services and insurance, orbit raising, and in-orbit
checkout. The N-STARs were launched aboard Ariane 44P vehicles.
N-STARs are based on SS/L’s three axis, body stabilized
1300 platform, whose modular design has proven its worth during
some 290 years of cumulative on-orbit service, close to one-half
of the total of 650 years amassed by SS/L satellites to date.
SS/L’s 1300 platforms are designed to achieve long useful
orbital life — in this case 10 years — through use
of a bipropellant propulsion system and a momentum-bias system
for excellent station keeping and orbital stability. Solar arrays
and nickel hydrogen batteries provide uninterrupted electrical
power.
Space Systems/Loral, a wholly owned subsidiary of Loral Space
& Communications, is a premier provider of a full range of
satellite systems and services, including the procurement
of insurance and launch services and mission control operations
from its Palo Alto, California, headquarters.
SS/L is ISO 9001 certified. SS/L’s product mix comprises
the 20.20 TM, the most powerful geostationary (GEO) commercial
spacecraft to fly, 1300 GE0 satellite platform and the 401S low-earth-orbit
(LEO) spacecraft. SS/L’s backlog consists of more than 60
satellites designed for applications such as digital telecommunications,
telephony, direct-to-home broadcast, environmental monitoring,
or air traffic control.
SS/L’s international customer base includes businesses and
government agencies involved in communications and environmental
monitoring. Customers for satellites under construction or recently
launched include: APSTAR, CD Radio, Chinasat, Globalstar, NASA,
INTELSAT, Rocketdyne, KaSTAR, Mabuhay, MTSAT, Loral Orion, PanAmSat,
Loral Skynet, and TEMPO. For more information, visit Space Systems/Loral’s
web site at http://www.ssloral.com.
Loral Space & Communications (NYSE:LOR) is a high technology
company that primarily concentrates on satellite manufacturing
and satellite-based services, including broadcast transponder
leasing and value added services, domestic and international
corporate data networks, global wireless telephony, broadband
data transmission and content services, Internet services, and
international direct-to-home satellite services.
For more information, visit Loral’s web site at http://www.loral.com.
SS/L satellites have amassed 650 years of cumulative on-orbit
service.
N-STAR
Space Systems/Loral
3825 Fabian Way
Palo Alto, California 94303-4697
650.852.4000 Fax 650.852.4788
http://www.ssloral.com 5/99