ST-1

Mission type	Communications
Operator	Singapore Telecom Chunghwa Telecom
COSPAR ID	1998-049A
SATCAT no.	25460
Mission duration	13 years
Spacecraft properties
Bus	Eurostar-2000+
Manufacturer	Matra Marconi
Launch mass	3,200 kilograms (7,100 lb)
Start of mission
Launch date	25 August 1998, 23:07 (1998-08-25UTC23:07Z) UTC[1]
Rocket	Ariane 44P V109
Launch site	Kourou ELA-2
Contractor	Arianespace
Orbital parameters
Reference system	Geocentric
Regime	Geostationary
Longitude	88° east
Perigee altitude	35,771 kilometres (22,227 mi)
Apogee altitude	35,813 kilometres (22,253 mi)
Inclination	1.83 degrees
Period	23.93 hours
Epoch	29 October 2013, 18:16:49 UTC[2]

ST-1 is a communications satellite owned by Singapore Telecom and Taiwan's Chunghwa Telecom Company, Ltd. It was placed launched on 25 August 1998, by an Ariane 4 rocket. The two companies jointly operate the spacecraft from control centres located in Seletar, Singapore and Taipei, Taiwan, respectively.

ST-1 carries 16 high-power K_u band transponders and 14 medium-power C-band transponders. Weighing over 3,000 kg (6,600 lb.) at launch, ST-1 generates more than 6,500 watts of electrical power. The satellite's broad C-band coverage beam extends from the Middle East to Japan, including all of Southeast Asia.

ST-1 also features two K_u-band spot beams: a "K1" beam that stretches from Taiwan to Singapore and from Indonesia to Malaysia and a "K2" beam centred over the Indian subcontinent. The ST-1 satellite currently delivers telephony, digital DTH broadcasting, VSAT and other business services throughout the region.

Singapore Telecom and Taiwan's Chunghwa Telecom Company are currently operating the replacement satellite ST-2 after ST-1 has reached its mission duration in 2011.