Definition
Intelsat 21 (also designated IS‑21) is a geostationary communications satellite operated by Intelsat, a global provider of satellite services. It delivers C‑band and Ku‑band telecommunications capacity across the Americas, Caribbean, and adjacent Atlantic regions.
Overview
Intelsat 21 was launched on 7 August 2012 aboard an Ariane 5 ECA launch vehicle from the Guiana Space Centre in Kourou, French Guiana. The satellite was placed into a geostationary orbit at 58° West longitude, where it remains in service providing broadband, broadcast, and data‑relay services to commercial, governmental, and maritime customers. Its operational design life is 15 years.
Etymology / Origin
The name “Intelsat” originates from the International Telecommunications Satellite Organization, the original intergovernmental consortium that established the commercial satellite fleet. The numerical suffix “21” follows Intelsat’s sequential naming convention for its spacecraft, indicating its position in the series of satellites launched by the company.
Characteristics
| Parameter | Details |
|---|---|
| Manufacturer | Boeing Satellite Development Center (formerly Boeing Satellite Systems) |
| Spacecraft bus | Boeing 702MP (Medium Power) platform |
| Launch mass | Approximately 4 700 kg |
| Power | Solar arrays delivering up to 12 kW of generated power |
| Transponders | 48 C‑band and 24 Ku‑band transponders |
| Frequency bands | C‑band (4–8 GHz) and Ku‑band (12–18 GHz) |
| Orbit | Geostationary orbit, 58° West longitude |
| Coverage area | North and South America, Caribbean, and Atlantic Ocean region |
| Design life | 15 years, with on‑orbit fuel and redundancy to support extended operation |
The satellite’s payload architecture enables a variety of services, including high‑definition television broadcasting, VSAT (very small aperture terminal) networking, and maritime communications. Its on‑board propulsion system employs a bipropellant chemical thruster for station‑keeping and orbit raising.
Related Topics
- Intelsat – The multinational satellite services provider that owns and operates the Intelsat fleet.
- Geostationary orbit (GEO) – The circular orbit approximately 35 786 km above Earth’s equator where satellites appear stationary relative to the ground.
- Ariane 5 – The European heavy‑lift launch vehicle used for the deployment of Intelsat 21.
- Boeing 702 satellite bus – A family of satellite platforms widely used for communications payloads.
- C‑band and Ku‑band communications – Frequency ranges commonly employed for satellite television, broadband, and data services.