Optus, Australia’s second largest telco and a subsidiary of Singapore Telecommunications Ltd., said its aging B1 satellite experienced an outage last week. The May 23outage was caused by a failure of the primary satellite control processor.

The outage led to two interruptions of service by New Zealand pay-TV operator Sky Network Television Ltd. The company said it is reviewing with Optus options to provide additional backup in case the original backup processor also fails.

Optus plans to launch a pair of new satellites, D1 and D2, with the first to be launched in 2006 and the second one 18 months later. Orbital Sciences Corp. is building the satellites, which will replace the B series satellites and will be used by broadcasters in Australia and New Zealand.