| Name of Satellite, Alternate Names | Optus and Defence C1 |
| Country of Operator/Owner | Australia |
| Operator/Owner | Optus Communications (Parent: Singapore Telecom)/Australian Ministry of Defence |
| Users | Military/Commercial |
| Purpose | Communications |
| Class of Orbit | GEO |
| Type of Orbit | |
| Longitude of GEO (degrees) | 156.06 |
| Perigee (km) | 35773 |
| Apogee (km) | 35799 |
| Eccentricity | 0.000308378404023152 |
| Inclination (degrees) | 0.02 |
| Period (minutes) | 1436.08 |
| Launch Mass (kg.) | 4800 |
| Dry Mass (kg.) | 2000 |
| Power (watts) | 10600 |
| Date of Launch | 12-06-2003 |
| Expected Lifetime | 15 yrs. |
| Contractor | Space Systems/Loral |
| Country of Contractor | USA |
| Launch Site | Guiana Space Center |
| Launch Vehicle | Ariane 5G |
| COSPAR Number | 2003-028B |
| NORAD Number | 27831 |
| Comments | 50% owned by Defence Ministry; largest hybrid communications and military satellite launched to date; 24 Ku-band, coverage for Australia, New Zealand and East Asia; commercial services in Ku-band (24), military (8) in X-, UHF- and Ka-bands. |