Horizons-1

Horizons-1, also known as Galaxy 13, is a geostationary communications satellite operated by Intelsat and SKY Perfect JSAT Group (JSAT) which was designed and manufactured by Boeing on the BSS-601 platform. It has K_u band and C band payload and was used to replace Galaxy 9 at the 127°West longitude.^[4] It covers North America, Puerto Rico, Alaska, Hawaii and Mexico.^[5][2][6][7]

Satellite description

The spacecraft was designed and manufactured by Boeing on the BSS-601 satellite bus. It had a launch mass of 4,060 kg (8,950 lb) and a mass of 2,630 kg (5,800 lb) at the begging of its a 15-year design life. When stowed for launch, it measured 5.7 m (19 ft) of height and 2.7 m × 3.6 m (8 ft 10 in × 11 ft 10 in) on its sides. Its solar panels span 26.2 m (86 ft) when fully deployed and, with its antennas in fully extended configuration it is 7.0 m (23.0 ft) wide.^[8]

It had two wings with four solar panels each that that used dual-junction GsAs solar cells. Its power system generated 9.9 kW of power at beginning of life and 8.9 kW at the end of its design life and had a 30-cell NiH battery for surviving solar eclipse.^[8]

Its propulsion system was composed of an R-4D-11-300 LAE with a thrust of 490 N (110 lb_f). It also used had 12 22 N (4.9 lb_f) bipropellant thrusters for station keeping and attitude control. For North-South stationkeeping, its primary method was an electric propulsion system with four XIPS 13, with four of the chemical thrusters acting as backup. It included enough propellant for orbit circularization and 15 years of operation.^[8][6]

It had two 107 in (2.7 m) Gregorian antennas and 50 in (1.3 m) two gridded shaped antennas.^[8]

Its K_u band payload is composed of twenty four active plus eight spares 36 MHz transponders powered by TWTA with an output power of 108 Watts. It covers North America, Puerto Rico, Alaska, Hawaii and Mexico and is known as Horizons-1.^{[8][9][6][10][11]}

The C band payload had another twenty four plus eight spares 36 MHz transponders powered by 40 Watts TWTA. It covers North America, Puerto Rico, Alaska, Hawaii and Mexico and is known as Galaxy 13, which was used to replace Galaxy 9.^[12][13][8]

History

Horizons Satellite was originally an equal share joint venture with PanAmSat. On September 4, 2001, it ordered from Boeing its first satellite, Horizons-1/Galaxy 13.^[4] It was a 4 t (4.4 tons) spacecraft with 24 C band and 24 K_u band transponders. It had a 10 kW power generation capacity and 15 years of expected life.^[8]

On the same day of the satellite order, Boeing disclosed that it had received an parallel contract from PanAmSat, where the latter had excercised an existing option to launch Horizons-1 from its Sea Launch subsidiary.^[14]

It was successfully launched on October 1, 2003 at 4:03 UTC, aboard a Zenit-3SL rocket from the Ocean Odyssey platform sationed at the 154°W over the Equator in the Pacific ocean.^[5][15]

In late 2005 PanAmSat was taken over by Intelsat who continued the joint venture.

References